HomeMy WebLinkAboutDune Palms NESDune Palms Road Low-Water Crossing Replacement Project
Natural Environment Study
Including Jurisdictional Waters Delineation
City of La Quinta, California
Federal Aid Project No. BRLKS-5433(014)
September 2015
Natural Environment Study
STATE OF CALIFORNIA
Department of Transportation
and
City of La Quinta
Prepared By: ___________________________________ Date: __9/25/2015___
Scott Taylor, Senior Biological Program Manager
ECORP Consulting, Inc.
Prepared By: ___________________________________ Date: _9/25/2015____
Lorraine Ahlquist, CEM, Environmental Manager
Parsons Brinckerhoff
Recommended
for Approval By: ___________________________________ Date: ____________
Denesse Segura, Associate Environmental Planner - Biologist
Phone Number: 909-806-4727
Biological Studies and Permits Branch
California Department of Transportation, District 8
Approved By: ______________________________________ Date: ____________
Craig Wentworth, Environmental Planner Branch Chief
Phone Number: 909-388-5212
Biological Studies and Permits Branch
California Department of Transportation, District 8
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Summary
The City of La Quinta Public Works Department (City) proposes to replace the existing
low-water crossing spanning the Coachella Valley Storm Water Channel (CVSWC)
(Whitewater River) at Dune Palms Road with an all-weather access and multimodal
bridge (Project). The proposed improvements will provide a reliable route for vehicles
and pedestrians and safe access across the CVSWC at Dune Palms Road during rain
events, and improve traffic circulation. There are no alternatives to this project.
Dune Palms Road serves as a vital north/south link for emergency services, and access to
La Quinta High, John Glenn Middle, and Amelia Earhart Elementary Schools. It also
provides connectivity with residential developments north of the CVSWC with Highway
111 located to the south (Figure 1). The CVSWC conveys surface water flow from the
surrounding mountains, as well as storm water runoff from developed areas within the
Coachella Valley. Currently Dune Palms Road crosses the CVSWC over a low-water or
‘Arizona’ crossing. Consequently, the crossing floods during rain events – even fairly
minor ones. Flooding of the crossing generally occurs at a frequency of every two years,
which results in full street closure, forcing the detour of both vehicular and pedestrian
traffic. In the interest of public health and safety, and in response to community concerns
regarding frequent closures of the low-water crossing on Dune Palms Road, the City of
La Quinta has determined that replacement of the low-water crossing with a bridge is
needed to ensure that access is maintained during the full range of weather conditions.
This Natural Environment Study (NES) documents an assessment of the proposed Project
and its potential impacts to sensitive natural resources. The NES presents the results of
several studies performed in support of the Project, including a jurisdictional delineation,
special-status wildlife species habitat assessments, and a focused rare plant survey.
Documentation of these studies is included in appendices to the NES. The NES and
supporting studies considered the natural resources within a Biological Study Area (BSA)
that includes all spatial components of the Project.
The BSA contains disturbed, developed, and natural habitat, primarily consisting of the
Dune Palms Road and the CVSWC. Adjacent areas to the Road and River are heavily
disturbed and are only partially affected by Project activities. The CVSWC is heavily
disturbed by grading and large mechanical equipment, likely from flood cleanups after
heavy rain events. Habitats and features jurisdictional to the U.S. Army Corps of
Engineers (USACE), California Department of Fish and Wildlife (CDFW), and Regional
Water Quality Control Board (RWQCB) were mapped within the CVSWC and would be
impacted by the proposed Project. Before construction activities begin for the proposed
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Project, the following approvals/ permits must be obtained or determined not applicable
through additional coordination with the applicable federal and state resource agencies:
• Streambed Alteration Agreement pursuant to California Fish and Game Code
Section 1602;
• USACE Nationwide Permit pursuant to CWA Section 404; and RWQCB 401 Water
Quality Certification pursuant to CWA Section 401.
The CVSWC is a hospitable corridor for local wildlife movement. Although Project
activities will temporarily affect corridor functionality, the planned bridge will improve
the corridor by creating a safe undercrossing for mobilizing wildlife. Currently, wildlife
that cross Dune Palms Road are at risk from moving vehicles and other pedestrian
activities residing on the low-crossing.
During reconnaissance surveys, no sensitive wildlife species were detected within the
BSA. During focused surveys for rare plants, no rare plant species were detected within
the BSA. Analysis of the Project area with respect to potentially-occurring species
revealed that the only potential species of concern for the Project include nesting bird
species and burrowing owls. Nesting birds could potentially occur throughout the Project
area, but burrowing owls are only anticipated to have potential to occur within the
southeast corner of the Project area. There is no critical habitat located within the BSA.
Mitigation measures to address the potentially-occurring species are summarized below.
To avoid effects to nesting birds, vegetation removals would occur outside of the nesting
bird season (i.e., February 15–August 31) to the maximum extent practicable. In the
event that vegetation clearing is necessary during the nesting season, the contractor will
have a qualified biologist conduct a preconstruction survey within 300 ft. of construction
areas no more than 30 days prior to construction at the location to identify the locations
of nests (if any). A qualified biologist is one that has surveyed for nesting bird species
within the Coachella Valley previously and has at least two years of prior nesting bird
survey experience. Should nesting birds be found, an exclusionary buffer will be
established by the qualified biologist around each nest site. This buffer will be a distance
from the construction activity based on the nest location, surrounding existing
disturbances and the species of bird that is nesting. The buffer will be clearly marked in
the field by construction personnel under guidance of the contractor’s qualified biologist,
and construction or clearing will not be conducted within this zone until the qualified
biologist determines that the young have fledged or the nest is no longer active.
The qualified biologist will monitor the nests on a weekly basis to ensure that
construction activities do not disturb or disrupt nesting activities. If the qualified biologist
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determines that construction activities are disturbing or disrupting nesting activities then
the biologist will notify the City. Responses may include, but are not limited to,
increasing the size of the exclusionary buffer, curtailing nearby work activities, turning
off vehicle engines and other equipment whenever possible to reduce noise, installing a
protective noise barrier between the nest and the construction activities, and/or working
in other areas until the young have fledged.
To ensure that any burrowing owl that may occupy the Project area are not affected by
construction activities, the contractor will be required to have preconstruction burrowing
owl surveys conducted by a qualified biologist within 30 days prior to any phase of
construction, including staging, in the areas identified as potential burrowing owl habitat.
These preconstruction surveys are also required to comply with the MBTA and the
California Fish and Game Code. If any of the preconstruction surveys determine that
burrowing owls are present, one or more of the following mitigation measures will be
required: (1) avoidance of active nests/burrows and surrounding buffer area during
construction activities; (2) passive relocation of individual owls; and (3) preservation of
on-site habitat with long-term conservation value for the owl. Because any presence of
burrowing owl must be documented and mitigation measures must be developed in
concert with the CDFW, the contractor’s qualified biologist, the City and CDFW will
determine which specific measure(s) will be implemented.
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Table of Contents
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Table of Contents
Summary ............................................................................................................................................ i
Chapter 1 – Introduction ................................................................................................................... 1
1.1 Purpose and Need .................................................................................................................. 7
1.1.1 Purpose ............................................................................................................................. 7
1.1.2 Need ................................................................................................................................. 7
1.2 Project Description ................................................................................................................. 7
1.2.1 Existing Conditions ........................................................................................................... 7
1.2.2 Proposed Improvements .................................................................................................. 8
1.2.3 Temporary Construction Bypass ....................................................................................... 9
1.2.4 Permanent COnstruction Limits ....................................................................................... 9
1.2.5 Right-of-Way Requirements ............................................................................................. 9
Chapter 2 – Study Methods ............................................................................................................. 14
2.1 Regulatory Requirements .................................................................................................... 15
2.1.1 Federal Policies and Regulations .................................................................................... 15
2.1.2 State Policies and Regulations ......................................................................................... 19
2.2 Studies Required .................................................................................................................. 21
2.2.1 Definition of the Biological Study Area ............................................................................ 21
2.2.2 Literature Search ............................................................................................................. 22
2.2.4 Survey Methods ............................................................................................................... 24
2.3 Personnel and Survey Dates ................................................................................................. 26
2.4 Agency Coordination and Professional Contacts ................................................................. 28
2.5 Limitations That May Influence Results ............................................................................... 29
Chapter 3 – Results: Environmental Setting .................................................................................... 31
3.1 Description of the Existing Biological and Physical Conditions ............................................ 31
3.1.1 Study Area ....................................................................................................................... 31
3.1.2 Physical Conditions .......................................................................................................... 32
3.1.3 Biological Conditions in the Biological Study Area .......................................................... 37
3.2 Regional Species and Habitats and Natural Communities of Concern ................................. 44
3.2.1 Critical Habitat ................................................................................................................. 44
3.2.2 Sensitive Plant Communities ........................................................................................... 48
3.2.3 Sensitive Plant Species .................................................................................................... 49
3.2.4 Sensitive Wildlife Species ................................................................................................ 49
Chapter 4 – Results: Biological Resources, Discussion of Impacts and Mitigation ............................ 55
4.1 Habitats and Natural Communities of Special Concern ....................................................... 55
4.1.1 Waters of the United States. ........................................................................................... 55
4.1.4 Waters of the State ......................................................................................................... 57
4.2 Special Status Plant Species ................................................................................................. 61
4.2.1 Coachella Valley Milk Vetch............................................................................................. 61
4.2.3 Other Sensitive Plant Species .......................................................................................... 62
Table of Contents
Dune Palms Road Crossing Replacement Project NES vi
4.3 Special Status Animal Species Occurrences.......................................................................... 63
4.3.1 Desert Pupfish ................................................................................................................. 63
4.3.2 Coachella Valley Fringe-toed Lizard ................................................................................. 64
4.3.3 Casey’s June Beetle ......................................................................................................... 65
4.3.4 Peninsular Bighorn Sheep ................................................................................................ 66
4.3.8 Other Sensitive Animal Species ....................................................................................... 66
Chapter 5 – Conclusions and Regulatory Determinations ................................................................ 71
5.1 Federal Endangered Species Act Consultation Summary ..................................................... 71
5.2 Essential Fish Habitat Consultation Summary ..................................................................... 71
5.3 California Endangered Species Act Consultation Summary ................................................. 71
5.4 Wetlands and Other Waters Coordination Summary .......................................................... 71
5.5 Invasive Species .................................................................................................................... 72
5.6 Other .................................................................................................................................... 72
5.6.1 Migratory Bird Treaty Act ................................................................................................ 72
5.6.2 Wild and Scenic Rivers ..................................................................................................... 74
Chapter 6 – References ................................................................................................................... 75
Appendix A – USFWS Species List .................................................................................................... 77
Appendix B – Flora and Fauna Species Compendium ...................................................................... 78
Appendix C – Jurisdictional Delineation Report ............................................................................... 79
Appendix D – Email Correspondence with Agencies ........................................................................ 80
Appendix E – Project Area Photographs .......................................................................................... 81
List of Figures and Tables
Dune Palms Road Crossing Replacement Project NES vii
List of Exhibits
Exhibit 1.1: Regional Project Vicinity. ...................................................................................................... 3
Exhibit 1.2: Local Project Vicinity. ........................................................................................................... 5
Exhibit 1.3: Temporary Impact Area. ..................................................................................................... 10
Exhibit 1.4: Permanent Impact Area. .................................................................................................... 12
Exhibit 3.1: Soils Map of the BSA. .......................................................................................................... 35
Exhibit 3.2: Vegetation Communities Map of the BSA. ......................................................................... 39
Exhibit 3.3: Designated Critical Habitat in the Project Vicinity.............................................................. 47
Exhibit 4.1: Jurisdictional Delineation Map. .......................................................................................... 59
List of Tables
Table 3-1: Regional Plant and Wildlife Species of Concern ................................................................... 51
Table 4-1: Potential USACE Jurisdictional Area Impacts........................................................................ 55
Table 4-2: Potential CDFW and RWQCB Jurisdictional Area Impacts .................................................... 57
List of Figures and Tables
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List of Figures and Tables
Dune Palms Road Crossing Replacement Project NES ix
List of Abbreviated Terms
AQMP Air Quality Management Plan
BA Biological Assessment
BMPs Best Management Practices
BSA Biological Study Area
BUOW Burrowing owl
Cal-IPC California Invasive Plant Council
The Department California Department of Transportation
CDFW California Department of Fish and Game
CEQA California Environmental Quality Act
CESA California Endangered Species Act
CFR Code of Federal Regulations
CHP California Highway Patrol
CNDDB California Natural Diversity Data Base
CNPS California Native Plant Society
CSA construction staging area
CWA Clean Water Act
Department California Department of Transportation
ECR Environmental Commitment Record
ECORP ECORP Consulting, Inc.
EO Executive Order
EPA U.S. Environmental Protection Agency
ESA Environmentally Sensitive Area
FESA Federal Endangered Species Act
FHWA Federal Highway Administration
ft. foot, feet
HCP Habitat Conservation Plan
HOV high-occupancy vehicle
I-10 Interstate 10
in. inch
MBTA Migratory Bird Treaty Act
mi mile(s)
NCCP Natural Community Conservation Plan
NEPA National Environmental Policy Act
NES Natural Environment Study
NPDES National Pollutant Discharge Elimination System
NRCS Natural Resource Conservation Service
OWUS other waters of the U.S.
PCE primary constituent element
PDT Project Development Team
List of Figures and Tables
Dune Palms Road Crossing Replacement Project NES x
PM post mile
PS&E plans, specifications, and estimate
ROW right-of-way
RPW Relatively Permanent Waters
RSS Riversidean coastal sage scrub
RTP Regional Transportation Plan
RWQCB Regional Water Quality Control Board
SAFETEA-LU Safe, Accountable, Flexible and Efficient Transportation
Act: A Legacy for Users
SAN Streambed Alteration Notification
SCAQMD South Coast Air Quality Management District
SSC species of special concern
SWPPP Stormwater Pollution Prevention Plan
TCE temporary construction easement
U.S.C. United States Code
USACE U.S. Army Corps of Engineers
USDA U.S. Department of Agriculture
USFWS United States Fish and Wildlife Service
USGS U.S. Geological Survey
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Chapter 1 – Introduction
This Natural Environment Study (NES) was prepared to document National
Environmental Policy Act (NEPA) and California Environmental Quality Act (CEQA)
compliance for the proposed Dune Palms Road Crossing Replacement Project, located in
La Quinta, Riverside County, California (Figures 1 and 2). The City of La Quinta (City)
proposes to replace the existing low-water crossing spanning the Coachella Valley Storm
Water Channel (CVSWC) (Whitewater River) at Dune Palms Road with an all-weather
access and multimodal bridge (Project). This NES provides an account of the existing
biological conditions in the Project area and vicinity, and an analysis of potential Project
effects to biological resources. It was prepared according to guidelines set forth in the
California Department of Transportation’s (Caltrans) NES Guidelines, Quality Control
and Assurance for Biological Technical Documents, and Standard Environmental
Reference, and includes data and analyses required by the U.S. Fish and Wildlife Service
(USFWS) in support of federal Endangered Species Act (ESA) compliance; by the
California Department of Fish and Wildlife (CDFW) in support of California Endangered
Species Act (CESA) compliance; and by the U.S. Army Corps of Engineers (USACE) in
support of compliance with the Clean Water Act (CWA), as well as other environmental
laws and policies overseen by these and other agencies. Caltrans serves as the lead
agency for NEPA compliance, as well as consultation under the ESA pursuant to the
Safe, Accountable, Flexible and Efficient Transportation Act: A Legacy for Users
(SAFETEA-LU), Section 6005, and as amended by the Moving Ahead for Progress in the
21st Century Act (MAP-21) to establish a revised and permanent Surface Transportation
Project Delivery Program. The City is the Project proponent and a responsible agency
under CEQA.
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1.1 Purpose and Need
1.1.1 PURPOSE
The City proposes to replace the existing low-water crossing spanning the Coachella
Valley Storm Water Channel (CVSWC) (Whitewater River) at Dune Palms Road with an
all-weather access. The Project will provide safe access across the CVSWC (Whitewater
River) during all-weather events, reliable route for emergency vehicles, motorists,
pedestrians, and bicyclists, and achieve the City’s General Plan goals for the corridor.
The Project has only one build alternative.
1.1.2 NEED
Dune Palms Road serves a vital access for emergency services within the project area, as
well as for La Quinta High, John Glenn Middle and Amelia Earhart Elementary Schools.
It also provides connectivity of the city residential development north of the Channel
with the Highway 111 commercial corridor located south of the CVSWC.
The CVSWC conveys storm water runoff from the surrounding mountains as well as
developed areas within the Coachella Valley. The elevation of the existing Dune Palms
Road low-water crossing causes it to flood during minor rain events (2-year frequency)
and results in full street closure and detour of both vehicle and pedestrian traffic. In the
interest of public health and safety, and in response to community concerns regarding
frequent closures of the low-water crossing, the City of La Quinta has determined that
replacement of the low-water crossing with a new bridge is needed to ensure that all-
weather access is maintained. The Dune Palms Road low-water crossing is the last
remaining low-water crossing of the CVSWC within the City.
1.2 Project Description
1.2.1 EXISTING CONDITIONS
The existing Dune Palms Road crosses the CVSWC at the channel grade. The roadway
width is 68 feet at the crossing, and consists of one northbound and two southbound
through lanes, eight foot wide walkway area along the western edge, and an eight foot
shoulder along the eastern edge of the road; and no median. The existing roadway
approach south of the crossing consists of one northbound and two southbound through
lanes. The northern roadway approach consists of one through lanes in each direction.
The transition from one to two lanes in the southbound direction occurs at the midpoint
of the channel crossing. Dune Palms Road approximately one-quarter mile north of the
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channel low-water crossing and just south of the project limits is a four lane roadway
with a median. The roadway section just north of the crossing will be widened as part of
an approved City project. The project was approved with a Mitigated Negative
Declaration under CEQA in April 2010.
1.2.2 PROPOSED IMPROVEMENTS
The project proposes to remove the existing low-water crossing of Dune Palms Road at
the CVSWC in the City of La Quinta, Riverside County. The crossing will be replaced
with a 480 feet long and 86 feet wide four-span bridge. The bridge typical section
consists of six-foot sidewalk on both sides of the bridge, two (2) eight-foot outside
shoulders also serving as bike/golf cart lanes, a 10 foot raised median, two (2) eleven-foot
travel lanes, and two (2) twelve-foot travel lanes. The proposed configuration will be
consistent with the existing four lane roadway section to the south, and the City’s current
improvement project to the north (project number 2009-04), which will widen Dune
Palms Road from two to four lanes with a median and left turn lanes.
The proposed improvements will include a reconstruction of the north and south bridge
approaches to accommodate the significant raised profile of the roadway. In order to
match the roadway section on the south side of the bridge, the project’s construction
limits will be extended to 239 feet of Highway 111. On the north side of the bridge, the
project construction limits will be extended to include a vacant lot immediately north of
the project limits. The vacant lot is owned by the City and will be offered by the City in
the bidding documents to be used for storage and construction staging by the contractor
for the construction of this project, if needed.
As a part of the bridge construction, concrete slope protection will be installed along the
north side of the channel. Additionally, minor removal and replacement of slope
protection will be required on the south side of channel west of the proposed bridge and
extension of slope protection approximately 300 feet downstream of the proposed bridge.
The slope protection is needed for scour countermeasures. As a result of the proposed
cast-in-place drilled shaft bridge construction, scour protection within the bottom of the
channel should not be required.
The project will also include the following additional improvements:
• Railing Architectural treatment. The bridge design will incorporate railing
architectural treatment as required by the City’s standard design.
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• Integration of a regional Bike/Pedestrian/NEV corridor (CV Link). The Coachella
Valley Association of Governments (CVAG) and the communities within the
Coachella Valley are working together on the implementation of a regional
Bike/Pedestrian/NEV corridor (CV Link) along Whitewater River and Coachella
Valley Storm Water Channel. The project design will be consistent with these
plans by allowing for the integration of a trail under crossing within the southern
slope protection, which also includes a trail connector to the pedestrian and bike
facilities proposed along Dune Palms Road in the project area.
• Utility Relocation. The project will also require utility relocations for overhead
electrical distribution lines (Imperial Irrigation District facility), adjustment to
both water valve can and lids and the manhole covers, minor 12” ductile iron pipe
water main relocations at each bridge abutment, and relocation of both a 12” and
18” sewer line at the northern bridge abutment.
1.2.3 TEMPORARY CONSTRUCTION BYPASS
The existing roadway will be modified to construct a temporary bypass road. The
temporary bypass will allow for staged construction of the bridge, and maintaining
vehicle and pedestrian access during the construction period. Temporary and short term
access impact may occur during construction, and will require coordination with property
owners, the public, and other stakeholders. The configuration of the temporary bypass
and short-term access is depicted in Exhibit 1.3.
1.2.4 PERMANENT CONSTRUCTION LIMITS
The Project will construct the bridge in a location that would roughly coincide with the
existing roadway footprint (Exhibit 1.4). This will minimize the permanent impacts to the
CVSWC and the associated environment.
1.2.5 RIGHT-OF-WAY REQUIREMENTS
The Project will require right-of-way acquisition on the northeast and southeast corners
of the proposed bridge. The existing development at the northeast corner of the proposed
bridge consists of a mobile home park with one single family home. Some of the mobile
homes adjacent to Dune Palms Road are encroaching within the street right-of-way. As a
consequence, the Project may require the acquisition of the single-family residence and
relocation of two mobile homes residents. The Project will be designed to avoid and
minimize relocation impacts of the mobile homes, to the extent possible.
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Exhi bit 1.3 Temporary Impacts
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Chapter 2 – Study Methods
This section discusses the regulatory requirements and the study methods for evaluating
the natural resources within the Project’s Biological Study Area (BSA). The following
studies were conducted within the BSA in support of the evaluation of the Project:
general biological plant and wildlife surveys; habitat assessment for burrowing owl
(Athene cunicularia); focused rare plant surveys; and a jurisdictional assessment of
waters and wetlands. These studies were conducted in support of obtaining Project
clearance/permission under requirements in several federal and state environmental
regulations, laws, and policies, described below.
Results of the studies are incorporated into this NES. A jurisdictional delineation report,
providing more detail than can be incorporated here, is provided as an attachment to this
document (Appendix D).
2.1 Regulatory Requirements
2.1.1 FEDERAL POLICIES AND REGULATIONS
2.1.1.1 Clean Water Act: Section 401
Section 401 of the CWA requires that a state water quality certification be obtained for
any action or project, including but not limited to dredge and fill projects that may result
in discharge of pollutants into waters of the United States. Under the Porter-Cologne
Water Quality Control Act (described under state regulations), the California State
Regional Water Quality Control Board (RWQCB) is provided the regulatory authority to
administer water quality certification decisions and grant National Pollutant Discharge
Elimination System (NPDES) permits, pursuant to CWA Section 401 compliance.
In California, before the USACE will issue a Section 404 permit (see below), applicants
must apply for and receive a Section 401 Water Quality Certification or waiver from the
RWQCB. Although the Water Quality Certification must be sought for the same effects
to Waters of the United States as indicated in a Section 404 permit, certification can also
cover effects to water bodies that are not USACE jurisdictional (i.e., isolated wetlands).
2.1.1.2 Clean Water Act: Section 404
Section 404 of the CWA requires that permission be obtained from the USACE for any
action or project, including but not limited to dredge and fill projects that may result in
discharge of materials into waters of the United States. These waters include wetlands
and non-wetland bodies of water that meet specific criteria as outlined in the guidelines
provided in the USACE 1987 Manual (USACE 1987) and are founded on a connection,
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or nexus, between the water body in question and interstate commerce. The following
definition of waters of the United States is taken from the discussion provided at Title 33
Code of Federal Regulations (CFR) Part 328.3:
“The term waters of the United States means:
(1) All waters which are currently used, or were used in the past, or may be
susceptible to use in interstate or foreign commerce…;
(2) All interstate waters including interstate wetlands;
(3) All other waters such as intrastate lakes, rivers, streams (including
intermittent streams)…the use, degradation or destruction of which could
affect interstate or foreign commerce…;
(4) All impoundments of waters otherwise defined as waters of the United States
under the definition; and
(5) Tributaries of waters defined in paragraphs (a) (1)–(4) of this section.”
USACE and the U.S. Environmental Protection Agency (EPA) define wetlands as
follows:
“Those areas that are inundated or saturated by surface or groundwater at a
frequency and duration sufficient to support, and that under normal
circumstances do support, a prevalence of vegetation typically adapted to
life in saturated soil conditions.”
To be considered a jurisdictional wetland under CWA Section 404, an area must possess
three wetland characteristics: hydrophytic vegetation, hydric soils, and wetland
hydrology. Each characteristic has a specific set of mandatory wetland criteria that must
be satisfied.
In 2006, the United States Supreme Court further considered USACE jurisdiction of
“waters of the United States” in the consolidated cases Rapanos v. United States and
Carabell v. United States (126 S. Ct. 2208), collectively referred to as Rapanos. The
Supreme Court concluded that wetlands are “waters of the United States” if they
significantly affect the chemical, physical, and biological integrity of other covered
waters more readily understood as navigable. On June 5, 2007, USACE issued guidance
regarding the Rapanos decision. This guidance states that USACE will continue to assert
jurisdiction over traditional navigable waters, wetlands adjacent to traditional navigable
waters, relatively permanent non-navigable tributaries that have a continuous flow at least
seasonally (i.e., typically 3 months), and wetlands that directly abut relatively permanent
tributaries. USACE will determine jurisdiction over waters that are non-navigable
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tributaries that are not relatively permanent and wetlands adjacent to or abutting non-
navigable tributaries that are not relatively permanent only after making a significant
nexus finding.
Furthermore, the preamble to USACE regulations (Preamble Section 328.3, Definitions)
states that USACE does not generally consider the following waters to be waters of the
United States; however, USACE does reserve the right to regulate these waters on a case-
by-case basis:
• Nontidal drainage and irrigation ditches excavated on dry land;
• Artificially irrigated areas that would revert to upland if the irrigation ceased;
• Artificial lakes or ponds created by excavating and/or diking dry land to collect and
retain water and used exclusively for such purposes as stock watering, irrigation,
settling basins, or rice growing;
• Artificial reflecting or swimming pools or other small ornamental bodies of water
created by excavating and/or diking dry land to retain water for primarily aesthetic
reasons;
• Water-filled depressions created in dry land incidental to construction activity and
pits excavated in dry land for purposes of obtaining fill, sand, or gravel unless and
until the construction or excavation operation is abandoned and the resulting body of
water meets the definition of waters of the U.S.
Waters found to be isolated and not subject to CWA regulation are often still regulated by
the RWQCB under the State Porter–Cologne Water Quality Control Act and CWA
Section 401.
2.1.1.3 Federal Endangered Species Act
The ESA, which is administered by the USFWS, is intended to protect and recover
imperiled species and their ecosystems. Under the ESA, species may be listed as either
Endangered or Threatened. “Endangered” means a species is in danger of extinction
throughout all or a significant portion of its range, whereas “Threatened” means a species
is likely to become endangered within the foreseeable future. Under the ESA, Congress
defined species to include subspecies, varieties, and, for vertebrates, distinct population
segments. The ESA protects listed and candidate species from “take” which is defined as
“to harass, harm, pursue, hunt, shoot, wound, kill, trap, capture, or collect, or to attempt
to engage in any such conduct.” Project-related take may only be allowed by the USFWS
through Sections 7 and 10 of the ESA, described below. Section 4(a)3(A) of the ESA also
provides authority to the USFWS to designate Critical Habitat for listed species.
Designated Critical Habitat is also protected from take.
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Section 7
Under provisions of the ESA, Section 7(a)(2), a federal agency that permits, licenses,
funds, or otherwise authorizes a project activity must consult with the USFWS to ensure
that its actions would not jeopardize the continued existence of any listed species or
destroy or adversely modify critical habitat that may be affected by the project.
Accordingly, Caltrans would be required to initiate formal ESA Section 7 consultation
with USFWS for any potential Project effects on listed species. During the Section 7
consultation process, the USFWS evaluates the potential for project-related take and
issues a Biological Opinion that provides measures for avoiding and minimizing take, as
well as permission for and limits on a certain amount of take.
Section 10
Section 10(a)(1)(B) of the ESA allows take of listed species under an agreement between
the USFWS and a project proponent, usually specified within a Habitat Conservation
Plan that provides for covered activities, covered species, and covered areas. The current
Project is located within the plan area for the Coachella Valley Multiple Species Habitat
Conservation Plan (MSHCP), a plan that is an agreement between the USFWS and
numerous plan signatories to allow for take of covered species during implementation of
projects. The MSHCP is a comprehensive, multi-jurisdictional Habitat Conservation Plan
(HCP) focusing on the long-term conservation of 27 species and their habitats (240,000
acres) in the Coachella Valley of Riverside County (County of Riverside 2007). Both the
City and Caltrans are permittees and signatories to the MSHCP.
2.1.1.4 Migratory Bird Treaty Act
The federal Migratory Bird Treaty Act (MBTA) protects all migratory birds, including
their eggs, nests, and feathers. The MBTA is enforced by USFWS, and potential
constraints to species protected under this law may be evaluated by USFWS during the
project consultation process. The USFWS typically requires that any actively breeding
pairs of migratory birds, their nests, and their eggs and young be protected from any
action or project. Breeding season for migratory birds protected under the MTBA
generally extends between February 15 and August 31 for most species.
2.1.1.5 Executive Order 11990: Protection of Wetlands
On May 24, 1977, President Carter signed Executive Order (EO) 11990, requiring federal
agencies to avoid to the extent possible the long and short term adverse impacts
associated with the destruction or modification of wetlands and to avoid direct or indirect
support of new construction in wetlands wherever there is a practicable alternative. The
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term “wetlands” is defined as those areas that are inundated by surface or ground water
with a frequency sufficient to support and under normal circumstances does or would
support a prevalence of vegetative or aquatic life that requires saturated or seasonally
saturated soil conditions for growth and reproduction. Examples of wetlands are also
provided in the EO: wetlands generally include swamps, marshes, bogs, and similar areas
such as sloughs, potholes, wet meadows, river overflows, mud flats, and natural ponds.
An Individual EO 11990 “Wetlands Only Practicable Alternative Finding” is required
from FHWA if a state project is federally-aided and involves fill in wetlands requiring a
USACE Section 404 Individual or Nationwide Permit (NWP) or a DEC/APA Article 24
Wetlands Permit. An additional requirement is to provide early public involvement in
projects affecting wetlands.
2.1.1.6 Executive Order 13112: Invasive Species
On February 3, 1999, President Clinton signed EO 13112, requiring federal agencies to
combat the introduction or spread of invasive species in the United States. The order
defines invasive species as “…any species, including its seeds, eggs, spores, or other
biological material capable of propagating that species, that is not native to that
ecosystem whose introduction does or is likely to cause economic or environmental harm
or harm to human health.” Federal Highway Administration (FHWA) guidance issued
August 10, 1999, directs the use of the state’s noxious weed list to define the invasive
plants that must be considered as part of CEQA analysis for a proposed project.
2.1.2 STATE POLICIES AND REGULATIONS
2.1.2.1 California Endangered Species Act
The CESA, which is administered by the CDFW, prohibits the take of plant and animal
species identified as either threatened or endangered in the State of California by the Fish
and Game Commission (Fish and Game Code Section 2050–2097). “Take” means to
hunt, pursue, catch, capture, or kill or attempt to hunt, pursue, catch, capture, or kill.
CESA Sections 2091 and 2081 allow CDFW to authorize exceptions to the prohibition of
take of the State-listed threatened or endangered plant and animal species for purposes
such as public and private development. CDFW requires formal consultation to ensure
that these actions would not jeopardize the continued existence of any listed species or
destroy or adversely modify critical habitat.
2.1.2.2 Porter-Cologne Water Quality Control Act
The Porter-Cologne Water Quality Control Act (Porter-Cologne Act) established nine
regional RWQCB offices and provides authority to the RWQCB to regulate State water
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rights and Section 401 of the CWA. Under the Porter-Cologne Act, the RWQCB
regulates actions that would involve “discharging waste, or proposing to discharge waste,
within any region that could affect the water of the state” (Water Code 13260(a)). The
RWQCB takes jurisdiction of surface waters that are outside of the jurisdiction of
USACE as “Waters of the State,” defined as “any surface water or groundwater,
including saline waters, within the boundaries of the state” (Water Code 13050 (e)).
Under this Act, the RWQCB regulates all such activities, as well as dredging, filling, or
discharging materials into Waters of the State, that are not regulated by the USACE due
to a lack of connectivity with a navigable water body or lack of an ordinary high water
mark (OHWM). The RWQCB can require mitigation measures beyond those required by
USACE or the CDFW; however, typically the mitigation proposed to satisfy USACE and
CDFW meets RWQCB requirements to offset impacts to water quality.
2.1.2.3 State of California Fish and Game Code
Sections 1600-1616
State of California Fish and Game Code Sections 1600-1616 requires that any person,
state, or local government agency, or public utility proposing a project that may affect a
river, stream, or lake to notify CDFW before beginning the project. If activities will result
in the diversion or obstruction of the natural flow of a stream; substantially alter its bed,
channel, or bank; impact riparian vegetation; or adversely affect existing fish and wildlife
resources, then a Streambed Alteration Agreement is required.
A Streambed Alteration Agreement lists the CDFW conditions of approval relative to the
project, and it serves as an agreement between an applicant and CDFW for a term of not
more than 5 years for the performance of activities subject to this section. A CDFW
Streambed Alteration Notification (SAN) is required for all activities potentially affecting
streambeds and/or their associated riparian habitats. Subsequently, implementation of the
project may require a 1602 Streambed Alteration Agreement if these areas are determined
to be jurisdictional by CDFW.
Section 2810: Natural Community Conservation Plan Act
The Natural Community Conservation Plan Act (NCCP), authorized under Assembly Bill
2172, established a process for multispecies conservation within California that allows
the CDFW to enter into agreements for the preparation and implementation of habitat
conservation plans. The NCCP process also allows for the articulation with federal
Habitat Conservation Plans developed and implemented under the ESA, utilizing both the
Section 4(d) Special Rule and the Section 10 Habitat Conservation Plan (HCP) processes.
The goal of the NCCP is to identify significantly important species and habitats and to
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develop ways and means to preserve and/or restore the ecological value of plant
communities and their attendant sensitive species in rapidly urbanizing settings.
The current Project is located within an existing NCCP, the MSHCP implemented under
Section 10 of the ESA.
Other Fish and Game Code Sections
California Fish and Game Code Section 3503 include provisions to protect the nests and
eggs of native birds. Sections 3511, 4700, 5050, and 5515 include provisions to protect
fully protected species, such as (1) prohibiting take or possession “at any time” of the
species listed in the statute, with few exceptions; (2) stating that “no provision of this
code or any other law shall be construed to authorize the issuance of permits or licenses
to “take” the species; and (3) stating that no previously issued permits or licenses for take
of the species “shall have any force or effect” for authorizing take or possession. CDFW
cannot authorize incidental take of “fully protected” species when activities are proposed
in areas inhabited by those species. Any project-related activities that could result in the
“take” of any fully protected species would have to be avoided.
2.2 Studies Required
2.2.1 DEFINITION OF THE BIOLOGICAL STUDY AREA
ECORP biologists characterized the biological resources in the Project area and
immediate vicinity by initially determining the limits of the BSA. The BSA is intended to
encompass the area within which all Project activities will occur, plus a buffer around the
Project site containing biological resources that may be indirectly impacted by Project
activities. ECORP determined that the BSA should include the entire “Temporary
Construction Easement” which includes all proposed work areas within the Project
boundary and additional areas up and downstream within the CVSWC (Exhibits 1.3 and
1.4). The BSA is based on preliminary Project design information that represents the
maximum area within which biological resources could potentially affected by the
proposed Project. Several highly modified anthropogenic features and environments in
the vicinity of the Project, including La Quinta High School, mobile home park, and
business developments in the immediate vicinity of the Project, are not included within
the BSA due to their highly modified character and low potential for occurrence of
biological resources. The BSA is comprised of 76.97 acres (31.15 ha), of which the
Project impact areas will occur over 10.92 acres (4.42 ha).
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2.2.2 LITERATURE SEARCH
Prior to performing the field surveys, ECORP biologists reviewed existing databases and
documentation to characterize the biological conditions within the BSA. This included
accessing the most recent records of sensitive species and habitat occurrences within the
California Natural Diversity Database (CNDDB) and the California Native Plant
Society’s (CNPS) Electronic Inventory of Rare and Endangered Vascular Plants of
California (Inventory). ECORP searched for CNDDB and CNPS Inventory records
within the La Quinta United States Geological Survey (USGS) 7.5-minute topographic
quadrangle on which the Project is situated, plus the surrounding eight topographic
quadrangles, including Cathedral City, Myoma, West Berdoo Canyon, Indio, Valerie,
Martinez Mountain, Toro Peak, and Rancho Mirage. The CNDDB and CNPS Inventory
contain records of reported occurrences of federal- or state-listed endangered, threatened,
proposed endangered, or threatened species; California Species of Special Concern
(SSC); or other special-status species or habitat that may occur within or in the vicinity of
the BSA. ECORP gathered additional information from the following sources:
• State and federally listed endangered and threatened animals of California
(CDFW 2014c);
• Special animals list (CDFW 2014d),
• California Natural Diversity Database Special Vascular Plants, Bryophytes and
Lichens List (CDFW 2014e);
• The Jepson Manual (Baldwin et al. 2012);
• Various online websites (e.g., CalFlora 2014);
• USFWS Critical Habitat Mapper;
• The Manual of California Vegetation, 2nd Edition (Sawyer et al. 2009); and
• National Resources Conservation Services’ Web Soil Survey (USDA 2014).
Using these sources of information and observations in the field, ECORP generated a list
of special-status plant and animal species with the potential to occur within or
immediately adjacent to the Project site. For the purposes of this assessment, special-
status species are defined as plants or animals that:
• Have been designated as either rare, threatened, or endangered by CDFW or the
USFWS, and are protected under either the CESA or FESA;
• Are candidate species being considered or proposed for listing under these same
acts;
• Are fully protected by the California FGC, Sections 3511, 4700, 5050, or 5515;
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• Are monitored by the CNDDB or the CNPS and are considered to be those of
greatest conservation need; and/or
• Are of expressed concern to resource and regulatory agencies, or local
jurisdictions.
In addition to performing searches in the CNDDB and CNPS Inventory, ECORP
biologists requested a list of proposed, threatened, or endangered species potentially
occurring within the BSA from the USFWS on March 26, 2015. The official USFWS
response is provided in Appendix A. ECORP additionally performed a search within the
Critical Habitat Portal for USFWS-designated habitat for federal listed species in the
vicinity of the BSA. ECORP also searched CNDDB records for occurrences of sensitive
natural vegetation communities.
ECORP assessed the potential for occurrence of special-status species and communities
within the BSA based upon records in the Project vicinity and/or presence of suitable
habitat in the BSA. The potential for occurrence of each species and community
evaluated in the literature search was categorized according to the following criteria:
Present: Species was observed within the BSA during a site visit or focused
survey.
High Potential: Habitat (including soils and elevation factors) for the species
occurs within the BSA and a known occurrence has been recorded
within 5 miles (8 kilometers) of the BSA.
Moderate Potential: Habitat (including soils and elevation factors) for the species
occurs within the BSA and a documented observation occurs
within the literature search, but not within 5 miles (8 kilometers) of
the BSA; or a documented observation occurs within 5 miles (8
kilometers) of the BSA and marginal or limited amounts of habitat
occurs in the BSA.
Low Potential: Limited habitat for the species occurs within the BSA and a
documented observation occurs within the literature search, but not
within 5 miles (8 kilometers) of the BSA; or suitable habitat
strongly associated with the species occurs on the BSA, but no
records were found within 5 miles (8 kilometers) of the BSA
during the literature search.
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Presumed Absent: Species was not observed during a site visit or focused surveys
conducted in accordance with protocol guidelines at an appropriate
time for identification; habitat (including soils and elevation
factors) does not exist on the BSA; or the known geographic range
of the species does not include the BSA.
(Note: Location information for some special-status species may be of questionable
accuracy or unavailable; therefore, for survey purposes, environmental factors associated
with species occurrence requirements may be considered sufficient reason to give a
species a well-defined potential for occurrence).
2.2.4 SURVEY METHODS
Following the literature search, ECORP biologists performed a number of surveys in the
BSA to determine and map the extent of vegetation communities and habitats, to conduct
focused surveys for rare plant species, to assess the presence of suitable habitat for
sensitive plant and wildlife species, and to conduct a jurisdictional delineation, described
below. A compendium of all flora and fauna observed during the field surveys is
provided in Appendix B.
2.2.4.1 Vegetation Community Mapping
ECORP biologists identified and mapped vegetation communities within the BSA during
an initial field visit. The vegetation communities within the BSA were classified
according to Holland’s Preliminary Descriptions of the Terrestrial Natural Communities
of California (1986 and 1992 update) and mapped using 7.5-minute USGS topographic
base maps and high-resolution aerial photography. Vegetation mapping was further
refined during the jurisdictional delineation field work.
2.2.4.2 Rare Plant Surveys
ECORP biologists conducted a series of rare plant surveys within the BSA during the
winter and spring of 2015 for the purposes of identifying the presence of any rare plant
species occurrences or populations. The surveys were conducted by qualified biologists
with experience conducting botanical surveys and knowledge regarding plant taxonomy,
plant species in the region, and special-status plant species. Survey methods conformed to
the following protocols: 1) Guidelines for Conducting and Reporting Botanical
Inventories for Federally Listed, Proposed, and Candidate Plants (USFWS 2002); 2)
Guidelines for Assessing the Effects of Proposed Projects on Rare, Threatened, and
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Endangered Plants and Natural Communities (CDFG 2000); and 3) CNPS Botanical
Survey Guidelines (CNPS 2001). All surveys were scheduled to coincide with the bloom
periods and during a period when target species were easily identified.
2.2.4.3 Burrowing Owl Habitat Assessment
ECORP biologists familiar with the habitat requirements for burrowing owl performed a
habitat assessment for the species within the BSA. Areas of burrowing owl habitat,
including any areas of open vegetation, such as grassy fields or disturbed vacant lots,
were mapped using 7.5-minute USGS topographic base maps and high-resolution aerial
photography. The biologists also mapped and noted areas of burrowing owl habitat that
contained mammal burrows that could support owl occupancy. The burrowing owl
habitat assessment was performed in accordance with protocol specified in the Staff
Report on Burrowing Owl Mitigation (CDFW 2012).
2.2.4.4 Jurisdictional Delineation
ECORP wetlands specialists performed a delineation of jurisdictional waters and
wetlands within the BSA in accordance with regulations set forth in 33 CFR Part 328 and
the USACE guidance documents referenced below:
• USACE Wetlands Research Program Technical Report Y-87-1 (online edition),
“Wetlands Delineation Manual,” Environmental Laboratory, 1987 (Wetland
Manual).
• USACE “Guidelines for Jurisdictional Determinations for Waters of the United
States in the Arid Southwest,” 2001 (Arid Southwest Guidelines).
• USACE “Minimum Standards for Acceptance of Preliminary Wetlands
Delineations,” November 30, 2001 (Minimum Standards).
• USACE “Regional Supplement to the Corps of Engineers Wetland Delineation
Manual: Arid West Region (Version 2.0),” September 2008 (Arid West
Supplement).
• USACE “Jurisdictional Determination Form Instructional Guidebook,” May 30,
2007 (JD Form Guidebook).
• USACE and EPA guidance (2007) and draft guidance on jurisdictional
delineations (2011).
Prior to entering the field, ECORP reviewed aerial photography, USGS 7.5-minute
topographic quadrangle maps, and National Wetland Inventory (NWI) to identify any
previously documented wetlands within the BSA. In addition, ECORP determined
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previously mapped soils within the BSA from United States Department of Agriculture’s
(USDA) Soil Survey Map.
ECORP wetland specialists used the unified federal method to delineate jurisdictional
areas using methodology outlined in the USACE Wetlands Delineation Manual
[Environmental Laboratory 1987] and the Regional Supplement to the Corps of
Engineers Wetland Delineation Manual: Arid West Region (Arid West Region
Supplement Version 2.0) [USACE 2008]. ECORP delineated the boundaries of potential
Waters of the U.S. through a field determination made in conjunction with aerial
photograph interpretation. A presentation of the full methodology and detailed results for
the jurisdictional delineation is provided in Appendix D.
2.3 Personnel and Survey Dates
The ECORP biologists who performed the studies in support of the Project include:
• Scott I. Taylor, B.A. Mr. Taylor performed the jurisdictional delineation and
authored the delineation report and NES. Mr. Taylor has over 24 years of
experience conducting biological studies, natural resource management, and
endangered species research for private and public sector projects, including
Caltrans Local Assistance Projects within the Coachella Valley and direct
contracts with Caltrans for On Call Biological Resource Studies. Within most of
the local jurisdictions of southern California, he has conducted biological
resources work for several of the endangered and threatened species that are
commonly associated with public projects in the Coachella Valley and elsewhere
within Riverside County. His experience includes identifying and surveying for
endangered/threatened species, biological and ecological surveys, jurisdictional
delineation, aquatic services, and regulatory permitting.
• Bradley Haley, B.A. Mr. Haley performed the initial biological reconnaissance of
the Project site and contributed to technical reports. Mr. Haley’s professional
experience involves ten years of field surveys and report preparation for projects
involving terrestrial and aquatic biological resources in southern California. Mr.
Haley conducts general habitat assessments, focused biological surveys, and
biological monitoring for listed and special-status wildlife and plant species. He
has specific expertise in conducting focused surveys for burrowing owl, nesting
birds, and vegetation communities. He has experience with data collection, field
survey techniques and protocols, and analysis on a variety of environmental issues
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as well as preparing various biological reports and NEPA/CEQA documents for
government agencies and private clients.
• Kristen Wasz, B.S. Ms. Wasz contributed to background research and technical
reports. Ms. Wasz has ten years of professional experience involving project
management and extensive field survey and report preparation for terrestrial and
aquatic biological resources in southern California. She specializes in leading and
conducting biological surveys and habitat assessments for listed and sensitive
wildlife species in southern California, including Palm Springs round-tailed
ground squirrel, burrowing owl, and nesting birds and raptors, among others. She
regularly conducts biological constraints analyses and assessments of potential
project-related impacts to sensitive biological resources. Ms. Wasz has also
authored many large and complex documents and technical reports, such as the
specific documents required by the California Department of Transportation,
analyses and reviews of impacts to natural resources for projects of varying sizes,
and National Environmental Policy Act (NEPA) and California Environmental
Quality Act (CEQA) documents.
• Josh Corona-Bennett, B.S. Mr. Corona-Bennett conducted the rare plant survey
and contributed to technical reports. Mr. Corona-Bennett has over 18 years of
experience in conducting biological resource studies and surveys, including
leading rare plant survey efforts for transportation projects, alternative energy
projects, and utility projects in southern California. In addition to performing rare
plant surveys, Mr. Corona-Bennett has prepared and implemented restoration and
revegetation plans, conducted horticultural and botanical/biological monitoring of
restoration and mitigation sites, collected seed from various rare plant species,
propagated native plants, and conducted vegetation community mapping.
• Kevin Cornell, B.S. Mr. Cornell assisted with the initial biological
reconnaissance, jurisdictional delineation, and rare plant surveys, and contributed
to the background research and technical reports. Mr. Cornell is an assistant
biologist with experience in biological reconnaissance, rare plant surveys,
restoration monitoring, habitat assessment, nesting bird surveys, raven nest
studies, jurisdictional delineations and construction monitoring. Mr. Cornell has
contributed to a variety of biological reports including nesting bird reports,
biological monitoring reports, biological assessments, annual monitoring reports,
and jurisdictional delineation reports.
The ECORP biologists performed field studies/surveys of the BSA on the following
dates:
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• Initial biological reconnaissance survey. This survey was conducted on
December 11, 2014 by Bradley Haley and Kevin Cornell. This visit consisted of a
reconnaissance of the Project site, recording of plant and wildlife species,
vegetation mapping, and habitat assessment for burrowing owl.
• Jurisdictional delineation. The jurisdictional delineation was conducted on
February 13, 2015 by Scott Taylor and Kevin Cornell. During this visit, the
biologists also recorded plant and wildlife species observed within the BSA.
• Rare plant survey. Evidence for the occurrence of the Coachella Valley milk-
vetch, which is an easy species to detect and identify when it is present, was
searched for during the initial biological reconnaissance survey on December 11,
2014 and the jurisdictional delineation on February 13, 2015. A rare plant survey
was conducted on March 20, 2015 by Brad Haley and Kevin Cornell.
2.4 Agency Coordination and Professional Contacts
ECORP Senior Biologist and Project Manager Michael Tuma sent an email to the
USFWS on December 5, 2014 requesting a list of proposed, threatened, or endangered
species potentially occurring within the BSA. USFWS Biologist Felicia Sirchia
responded via telephone on December 12, 2014, requesting that the BSA be evaluated for
the presence of the endangered Coachella Valley milk-vetch (Astragalus lentiginosus var.
coachellae).
Following two visits to the BSA to search for Coachella Valley milk-vetch, ECORP
Senior Biologist and Project Manager Michael Tuma sent an email to Ginny Short,
Biologist with the Center for Natural Lands Management and manager of several
preserves in the Coachella Valley that support Coachella Valley milk-vetch populations,
on February 24, 2015. Ms. Short responded that the area had not received sufficient
precipitation to germinate milk-vetch seeds, and that it would be difficult to find the plant
during the 2015 season. Following this response, Mr. Tuma again contacted Ms. Sirchia
at the USFWS to inquire how the USFWS would recommend proceeding. Ms. Sirchia
responded with a recommendation for additional survey work to cover the spring months
as well as recommendations for inclusion of best management practices (BMP) within the
NES. Copies of the email requests to and responses from agency coordination and
professional contacts are provided in Appendix D.
Ultimately the milk vetch was observed blooming at a reference site in March 2015 and
surveys were undertaken at the Project area.
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2.5 Limitations That May Influence Results
The developed areas surrounding the BSA include a number of private properties that
were not accessible during the field surveys. Wherever feasible, a visual assessment of
these adjacent properties was conducted during the fieldwork; however, in areas where a
wall, solid fence, or dense vegetation was present, it was not possible to assess adjacent
properties. ECORP biologists relied on aerial imagery, including Google Earth, to
characterize the biological conditions on these adjacent properties, which consisted
primarily of urbanized developments.
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Chapter 3 – Results: Environmental Setting
3.1 Description of the Existing Biological and Physical Conditions
3.1.1 STUDY AREA
3.1.1.1 Regional Environmental Setting
The BSA is located in the Coachella Valley, which is the northern extent of a large
lowland trough extending northward from the Gulf of Mexico to the San Gorgonio Pass.
The Coachella Valley thus extends in the north from the San Gorgonio Pass, a mountain
gap between the San Bernardino Mountains and the San Jacinto Mountains northwest of
Palm Springs, southeastward to the northern extent of the Salton Sea, a man-made lake
within the former Salton Sink dry lakebed. The BSA is located in the south-central
portion of the Coachella Valley, which is bounded on the south and west by the Santa
Rosa Mountains and to the north and east by the Little San Bernardino Mountains. This
portion of the Coachella Valley includes the Whitewater River, which originates in the
San Bernardino Mountains and flows through the valley floor. To contain and control
periodic flash flooding within urbanized areas of the Coachella Valley, the CVWD has
channelized portions of the Whitewater River, including the reach of the river in the
vicinity of the BSA. The channelized Whitewater River currently flows through the
CVSWC, over which the Project will be constructed.
The Coachella Valley has historically been one of the fastest growing human population
centers in southern California, with a population of nearly 400,000 residents distributed
across nine cities and various unincorporated communities. Urban development is a
prominent feature across the Coachella Valley, including residential and commercial
developments, but also numerous golf courses and resorts. Other prominent land uses
include alternative energy developments in the northwestern portions of the valley and
agriculture in the southeastern portion. Numerous anthropogenic linear features traverse
the valley, including Interstate 10, the Coachella and All-American Canals, and the Path
42 Electrical Transmission Line, among many others.
Several preserve areas are located in the Coachella Valley and the environs, including the
San Gorgonio Wilderness, Whitewater Preserve, Mission Creek, Big Morongo Canyon
Preserve, Joshua Tree National Park, the Salton Sea, Anza Borrego Desert State Park,
Santa Rosa Mountains, San Jacinto Mountains, Snow Creek, and Mount San Jacinto State
Park. All of the preserve areas mentioned are more than five miles away from the Project
area and are not connected geographically, via undeveloped lands, to the Project area.
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Therefore no substantial connectivity or wildlife movement issues exist between the
regional preserves listed and the Project area.
3.1.1.2 Local Environmental Setting
La Quinta is bounded on the west by the City of Indian Wells, the north by the
unincorporated community of Bermuda Dunes, to the south by undeveloped lands of the
Santa Rosa Mountains, and the east by the City of Indio. Development within the City
consists primarily of residential and commercial uses, with secondary uses consisting of
golf course developments and public open space. The CVSWC runs through the Project
area and effectively bisects the City. The Project area is located in a heavily urbanized
part of the City of La Quinta. Developments in the immediate vicinity of the BSA include
La Quinta High School and residential developments immediately to the north, and
several commercial developments (shopping centers) to the south. One undeveloped
parcel zoned for additional commercial, occurs to the southeast of the Project, abutting
the CVSWC but otherwise surrounded by developed areas.
3.1.2 PHYSICAL CONDITIONS
3.1.2.1 Topography
Natural topography is absent within the Project area and its vicinity. Local topography in
the Project area consists of a developed flood control channel surrounded by upland areas
that have either been graded or developed. Elevation in the BSA ranges from 45 feet
above MSL within the CVSWC to 75 feet above MSL on Dune Palms Road at the
southern extent of the Project site.
La Quinta is part of the Coachella Valley, situated in the northwestern extent of a large
geographical trough that pre-historically was a northern extension of the Gulf of
California. The valley floor ranges in elevation from 1,600 feet above mean sea level
(MSL) in the northwest to about 227 feet below MSL at the Salton Sea. With the
exception of the Indio Hills, the Coachella Valley is generally broad and flat with sloping
alluvial fans at the mouths of mountain canyons.
3.1.2.2 Hydrology
The BSA is traversed by the Whitewater River, which is channelized within the CVSWC,
over which the Project will be constructed. The Whitewater River is a 45 mile stream that
originates in the San Bernardino Mountains and terminates near the Salton Sea. The
majority of its length is channelized. Flows within the western limits of Whitewater River
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are heavily manipulated by releases from the Colorado River Aqueduct that assist in
maintaining the groundwater levels in the Coachella Valley. Groundwater stemming from
percolation along the CVSWC is diverted for many uses within the Coachella Valley
(County of Riverside General Plan 2012).
The Whitewater River watershed originated in the San Bernardino Mountains near Mount
San Gorgonio. The river is not dammed or diverted, but is influenced by input from the
CRA north of I-10 and by urban surface water runoff between the cities of Banning and
Coachella. Most of the Whitewater River surface flows entering the Coachella Valley are
collected within a series of recharge basins at the northern portion of the urbanized
portions of the valley. In the vicinity of the BSA, several miles south of these recharge
basins, the CVSWC conveys little of the upstream flows from the Whitewater River, but
consists mostly of storm water runoff from the surrounding mountains and urban runoff
from developed areas within the Coachella Valley. The CVSWC is designed to convey
82,000 Cubic Feet Per Second (CFS) of water, which is the Specific Project Flood (SPF)
flow.
3.1.2.3 Soils
The soils within the BSA have been highly modified from their natural condition through
anthropogenic disturbances associated with urbanization, road construction, and
channelization of the Whitewater River into the CVSWC. Two soil types have been
mapped in the BSA by the NRCS Web Soil Survey, including Coachella fine sand in the
CVSWC and Myoma fine sand in the adjacent uplands (Exhibit 3.1). The Coachella
series soils are characterized as well-drained, moderately to rapidly permeable soils. They
are alluvial soils formed predominantly from igneous rocks and are found in water
channels and basins. The Myoma series soils are eolian sediments that originated from
recent alluvium, and are characterized by moderately alkaline, fine and very fine sands.
In their natural state they are nearly level to rolling, with hummocky micro-relief.
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MaD
MaD
MaB
CpA
CpA
CpACpA
Exhi bit 3.1SoilsMap Date: 3/13/2015Photo Source: NAIP (2012)
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0 400
S c a l e i n F e e t
Map Feature s
Temporary Construction Easement
NRCS Soil Types
CpA - C oachella fine sand, 0 to 2 percent slopes
MaB - Myoma fine sand, 0 to 5 percent slopes
MaD - Myoma fine sand, 5 to 15 percent slopes
Natura l Resources Conservation Servi ce (NRCS)Soil Survey Geographic (SSURGO) Database for Riverside County, CA
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3.1.3 BIOLOGICAL CONDITIONS IN THE BIOLOGICAL STUDY AREA
3.1.3.1 Vegetation Communities
The BSA is comprised of predominantly disturbed riparian herbaceous areas associated
with the CVSWC. There is also a small amount of freshwater marsh associated with a
pipe that releases urban runoff into the channel. The upland areas comprise developed
and disturbed areas. There are no intact, natural vegetation communities in the BSA,
though there are several areas in that support scattered native shrubs, including rubber
rabbitbush, creosote (Larrea tridentata), and fourwing saltbush (Atriplex canescens).
Following is a description of each habitat type in the BSA.
Freshwater Marsh
Marsh habitats are wet areas associated with frequent inundation. Naturally these areas
are associated with either perennial streams or lakes or ponds. But in special
circumstances where water is frequently present, they can develop without those
geographical features being present. The marsh located within the Project area, along the
western side of Dune Palms Road within the northern side of the CVSWC, results from
runoff from the direction of the high school into the CVSWC via an existing storm drain
system and outlet. The stormwater empties into a short gully before seeping into the
sandy areas of the larger channel. Vegetation within this marsh area includes narrow-
leaved cattail (Typha latifolia), rabbit-foot grass (Polypogon monspeliensis), and
cocklebur (Xanthium strumarium). The marsh is approximately 0.03 acre in extent within
the BSA and is located outside of the proposed work areas.
Disturbed Riparian Herbaceous
Disturbed Riparian Herbaceous habitat is characterized by non-native, often annual plants
associated with the CVSWC. Many of the plant species within the channel are considered
“ruderal” plants, associated with human settlements and urban areas, such as vacant lots,
but also along edges of agricultural fields and other human-modified environments.
Dominant species in this community on site include castor bean (Ricinis communis),
Russian thistle (Salsola tragus), cheeseweed (Malva parviflora), common sow-thistle
(Sonchus oleraceus) and non-native annual grasses such as wild oat (Avena sp.) and rip-
gut brome (Bromus diandrus). The habitat is approximately 5.77 acres in extent within
the BSA and is partially located within the proposed work areas within the CVSWC
portion of the Project.
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Disturbed/Developed Areas
Disturbed/Developed is not a vegetation classification, but rather a land cover type that is
either largely devoid of vegetation due to human development, or dominated by unnatural
vegetation such as lawns and landscaping. Often areas surrounding this land cover type
support non-native, invasive plant species. Disturbed/Developed cover type occurs in the
northern portion of the BSA, as well as along the Dune Palms Road alignment (Figure 7).
Portion of the BSA, predominantly within and bordering developed areas, are planted in
ornamental vegetation. Numerous non-native plants used in landscaping these areas
within the BSA include eucalyptus trees (Eucalyptus sp.), Peruvian pepper tree (Schinus
molle), Mexican fan palm (Washingtonia robusta), oleander shrubs (Nerium oleander),
and hottentot fig (Carpobrotus edulis). Disturbed habitats within the vacant parcel on
adjacent uplands is dominated by lamb’s quarters (Chenopodium album), black mustard
(Brassica nigra), Bermuda grass (Cynodon dactylon), and purple fountain grass
(Pennisetum setaceum). Scattered throughout the disturbed habitat are a few native
perennial shrubs, including creosote (Larrea tridentata) and fourwing saltbush (Atriplex
canescens); however the disturbed nature of the soils and vegetation where these shrubs
occur, as well as the paucity of native perennial shrubs, precludes these areas from being
characterized as desert scrub habitat. Within the BSA, approximately 1.97 acres is
considered disturbed and 3.15 acres are considered developed.
DDuunneePPaallmmssRRddCCoorr ttee zz LLnnRoudel LnRoudel LnCorporate Centre Dr
Corporate Centre Dr
£¤111
Exhi bit 3.2Vegetation Commu nities
Map Date: 3/25/2015Photo Source: USGS (2012)
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Vegeta tion Co mmunity
Fre shwat er Marsh (0.03 acres)
Disturbed R iparia n Herbaceous (5 .77 acre s)
Disturbed (1.9 7 ac res)
Develop ed (3.15 a cres)
I
0 300
S c a l e i n F e e t
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3.1.3.2 Dominant Plant Species
Plant species in the BSA are characteristic of highly disturbed, anthropogenically-
modified environments, and include predominantly ruderal and ornamental species.
Channel areas are dominated by castorbean; the dominant ornamental plant in landscaped
areas is oleander.
A compendium of plant species observed within the BSA is found in Appendix B.
3.1.3.3 Common Animal Species
Numerous common wildlife species that are preadapted to tolerate anthropogenically-
modified environments were observed in the BSA. Wildlife species most frequently
observed include common raven (Corvus corax), rock dove (Columba livia), northern
mockingbird (Mimus polyglottos), black phoebe (Sayornis nigricans), Eurasian-collared
dove (Streptopelia decaocto), and European starling (Sturnus vulgaris). Most of these
species were observed perched on distribution poles, wires, fences, and in ornamental
trees on the periphery of the BSA, whereas only a few were observed near Dune Palms
Road or within the CVSWC. No other wildlife other than birds and common insects were
observed within the Project BSA. Although not observed, the Project site may host
multiple lizard species, rabbits, ground squirrels, and coyotes.
A compendium of wildlife species observed within the BSA can be found in Appendix B.
3.1.3.4 Aquatic Resources
The major aquatic resource within the BSA is the channelized Whitewater River
alignment within the CVSWC. The channel in this location is highly modified from its
original form due to being channelized, and is regularly maintained by the CVWD to
reduce sediment and maintain flows. The channel in the urbanized area is characterized
as having an earthen bottom and a mixture of earthen and concrete slopes on the sides,
thus supporting vegetation growth. The water flow is intermittent and the CVSWC
conveys surface storm water runoff during significant rain events, which typically occur
during the winter season, but may also occur during summer monsoon season.
Local urban runoff flows into the site via a pipe along the north side of the channel west
of Dune Palms Road. This runoff has been consistent enough to sustain a small patch of
freshwater marsh along a gully. The patch is approximately 0.03 acre in extent. This plant
community represents the only truly aquatic habitat type within the Project area.
Although this freshwater marsh habitat patch is small in extent and supported by urban
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runoff, there is potential for aquatic invertebrates to occur within portions where water
pools. Invertebrates expected to occur would include common species associated with
urban environments such as mosquito larvae (Family Culicidae) or predaceous diving
beetles (Family Dytiscidae). However, this patch of habitat clearly did not occur
historically and, due to its small extent, no substantial native aquatic resources are
expected to use the marsh habitat. Aquatic plants and animals do not occur within the
remainder of the river channel or in the remaining BSA.
3.1.3.5 Invasive Species
Due to the location of the Project site in an urbanized area and the anthropogenically-
modified environments in the BSA, there are numerous non-native, invasive species of
plants and wildlife present. Three invasive plant species dominate much of the vegetated
areas within the BSA, including castorbean, Russian thistle, and Mediterranean tamarisk
(Tamarix ramosissima). All three of these species are considered exotic and invasive by
the California Invasive Plant Council (Cal-IPC). Castorbean is an herbaceous plant or
semi-woody large shrub or small tree. It grows quickly in mild climates and has escaped
cultivation to become a noxious weed in southern and central California. Russian thistle
is a large, bushy summer annual. It can be found throughout California, including in
agricultural areas, desert, roadsides and other disturbed areas. Mediterranean tamarisk is a
shrub or a tree and can be found along streams and lake shores, throughout California.
Mediterranean tamarisk is associated with dramatic changes in geomorphology,
groundwater availability, soil chemistry, fire frequency, plant community composition,
and native wildlife diversity.
Other non-native plant species listed as invasive by the Cal-IPC that present in the BSA
include:
• Black mustard (Brassica nigra)
• Tree tobacco (Nicotiana glauca)
• Bermuda grass (Cynodon dactylon)
• Purple fountain grass (Pennisetum setaceum)
Other non-native plant species that are not considered invasive by the Cal-IPC but are
naturalized and present in the BSA include:
• Oleander (Nerium oleander)
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• Lamb’s quarter (Chenopodium album)
• Sourclover (Melilotus indica)
• Puncture vine (Tribulus terrestris)
No substantial populations of invasive wildlife were documented in the BSA, though
several individuals of rock dove, Eurasian-collared dove, and European starling were
observed within and near the BSA. Other non-native, invasive wildlife, including house
sparrows (Passer domesticus), Virginia opossums (Didelphis virginiana), and the
Norway rat (Rattus norvegicus), are known to occur in urban areas in the Project vicinity,
as do feral dogs (Canis lupus familiaris) and cats (Felis catus).
3.1.3.6 Habitat Connectivity
Habitat connectivity is established when a wildlife movement corridor connects two
blocks of undeveloped wildlife habitat. The habitat areas connected can be either native
or non-native areas, as long as they support wildlife values. A wildlife corridor is defined
as a linear path between such habitats that functions to allow for genetic interchange
between wildlife populations. Wildlife corridors provide genetic interchange between
otherwise separate wildlife populations and effectively increase the wildlife population
viability within each connected block of habitat. They are also useful for dispersal of
yo ung animals, and means of escape and survival during stochastic disturbances such as
fire, flood, or other large-scale disturbance.
The Project area contains one potential wildlife corridor, the CVSWC. This corridor is
highly disturbed, relatively narrow, and traverses through highly urbanized areas. The
distance along the CVSWC between the Project area and the nearest substantial (> 100
acres) native area of undeveloped land is eight miles to the northwest. To the southeast,
the channel runs through several cities and eventually crosses Highway 86S
approximately 4.5 miles north of its outlet into the Salton Sea. No substantial wildlife
movement along the CVSWC between these large blocks of open lands is expected due
to the disturbances present.
Local movement between isolated habitat patches is a more likely scenario. Several
smaller vacant lots, similar to the vacant lot southeast of Dune Palms Road, line the
CVSWC or are proximal to the channel along its length. There is also a golf
course/residential community east of Dune Palms Road and another golf course to the
north of that one that both provide wildlife habitat opportunities. Most of the species
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using the golf courses are expected to be well-adapted to urban environments, and
common species, such as house finches (Carpodacus mexicanus), coyotes (Canis
latrans), and desert cottontail (Sylvilagus audubonii). Nevertheless, the CVSWC
undoubtedly provides a local movement corridor for these species throughout much of
the Coachella Valley between urban habitat patches. The CVSWC also represents a local
water source during local rain events and provides some vegetative cover as well as a
source of invertebrate prey base.
Although the amount of urban development along most of the CVSWC severely limits its
functionality as a regional wildlife movement corridor, it can serve as a local movement
corridor.
3.2 Regional Species and Habitats and Natural Communities of
Concern
3.2.1 CRITICAL HABITAT
Critical Habitat has been designated for seven federally-listed species in the Project
vicinity, including Coachella Valley milk-vetch (Astragalus lentiginosus var.
coachellae), Casey’s June beetle (Dinacoma caseyi), Quino checkerspot butterfly
(Euphydryas editha quino), Mountain yellow-legged frog (Rana muscosa), Agassiz’s
desert tortoise (Gopherus agassizii), Coachella Valley fringe-toed lizard (Uma inornata),
and peninsular bighorn sheep (Ovis canadensis nelsoni). None of these critical habitat
areas overlap the Project area. Descriptions of the Critical Habitat Units for these species,
and their geographic relationship to the BSA, are provided below. A map of the critical
habitat areas in the site vicinity is included as Exhibit 3.3 below.
3.2.1.3 Coachella Valley Milk-Vetch
This critical habitat area occurs north of I-10, approximately 5 miles north and west of
the Project area. Habitats within the critical habitat consist of dune areas, of which no
representation is found within the Project area.
3.2.1.2 Casey’s June Beetle
This critical habitat area occurs approximately 15 miles west of the Project area. Habitats
within the critical habitat consist of habitat areas within Palm Canyon south of Palm
Springs. The species habitat is absent from the Project area.
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3.2.1.7 Quino Checkerspot Butterfly
Critical habitat for this species occurs west of Mount San Jacinto within western
Riverside County. No suitable Quino checkerspot butterfly habitat occurs within the
Project area.
3.2.1.5 Mountain Yellow-Legged Frog
Critical habitat for this species occurs on the western-facing slopes of Mount San Jacinto
within western Riverside County. No suitable mountain yellow-legged frog habitat
occurs within the Project area.
3.2.1.4 Agassiz’s Desert Tortoise
Critical habitat for this species occurs in the Chocolate Mountains substantially east of
the Project area. No suitable desert tortoise habitat occurs within the Project area.
3.2.1.1 Coachella Valley Fringe-Toed Lizard
This critical habitat area occurs north of I-10, approximately 5 miles north and west of
the Project area. Habitats within the critical habitat consist of dune areas, of which no
representation is found within the Project area.
3.2.1.6 Peninsular Bighorn Sheep
Critical habitat for this species occurs in the lower San Jacinto Mountains west of the
Project area. No suitable bighorn sheep habitat occurs within the Project area. Although
the sheep do sometimes occur within and near urbanized settings in the Coachella Valley,
these sightings are made within canyons that abut large, undeveloped open spaces.
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Project Area
ST195
ST62
ST86S
ST371
ST86
ST74
ST111 ¨§¦10
Exhibit 3.3 Designated Critical Habitatin the Project Vicinity.
Map Date: 3/4/2015
1 US Fish and Wildlife Service
Photo Source: NAIP 2012
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Critical Habitat 1
Coachella Valley Fringed Toed Lizard
Caseys June Beetle
Coachella Valley Milk Vetch
Desert Tortoise
Mountain Yellow Legged Frog
Peninsular Bighorn Sheep
Quino Checkerspot Butterfly
I
0 2.5 5 7.5
Miles
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3.2.2 SENSITIVE PLANT COMMUNITIES
The literature review and database query determined that one sensitive plant community
has been recorded within five miles of the BSA: Desert Fan Palm Oasis Woodland.
Desert Fan Palm Oasis Woodland is dominated by native fan palms (Washingtonia
filifera) with several associated shrub species. The community occurs within the bottoms
of deep canyons of the eastern San Jacinto Mountains against the urban areas of the
Coachella Valley floor. The nearest recorded location of this community is within
Magnesia Spring Canyon near Rancho Mirage, approximately seven miles west of the
Project area. No fan palms occur within the Project area.
All riparian plant communities are considered to be sensitive plant communities because
their distribution is relatively rare and limited. The freshwater marsh located on site is
considered to be a riparian habitat type and a sensitive plant community. Disturbed
riparian herbaceous is likewise considered to be a riparian habitat type, although it is
dominated by disturbed plant species and is of low habitat value.
3.2.3 SENSITIVE PLANT SPECIES
The literature review and database query determined that 40 special-status plant species
have been recorded in the region. Of these, four are known to occur within five miles of the
BSA and one has been recorded within a mile of the BSA. Species recorded within five miles
of the Project area include glandular ditaxis (Ditaxis claryana), California ditaxis (Ditaxis
californica), chaparral sand verbena (Abronia villosa var. aurita), and slender cottonheads
(Nemacaulus denudata var. gracilis). Glandular ditaxis was observed closest to the Project
area, to the south adjacent to Highway 111. None of these species are formally listed at either
state or federal levels.
All of the special-status plant species analyzed for the Project, including those recorded
within five miles of the BSA, are summarized in Table 3-1. These designations are based
on their current distribution, habitat requirements, and information concerning land use
within the vicinity of the BSA. Based on surveys discussed in Section 2.2 and the
rationale discussed for each species in Table 3-1, all of the plant species analyzed are
unlikely to occur within the BSA.
3.2.4 SENSITIVE WILDLIFE SPECIES
The literature review and database query determined that 31 special-status animal species
have been recorded occur in the region. Of these, 12 wildlife species are known to occur
within five miles of the BSA and three have been recorded within a mile of the BSA.
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Wildlife species recorded within five miles of the Project area include Coachella Valley
fringe-toed lizard (Uma inornata), burrowing owl (Athene cunicularia), Le Conte’s thrasher
(Toxostoma lecontei), Coachella giant sand-treader cricket (Macrobaenetes valgum), black-
tailed gnatcatcher (Polioptila melaneura), prairie falcon (Falco mexicanus), pocketed free-
tailed bat (Nyctinimops femorosaccus), flat-tailed horned lizard (Phrynosoma mcallii), Palm
Springs round-tailed ground squirrel (Xerospermophilus tereticaudus chlorus), western
yellow bat (Lasiurus xanthinus), Casey’s J une beetle (Dinacoma caseyi), and loggerhead
shrike (Lanius ludovicianus). Coachella Valley fringe-toed lizard, the giant sand-treader
cricket, and Palm Springs round-tailed ground squired were observed closest to the Project
area. Of these three species recorded closest to the Project area, the fringe-toed lizard is
formally listed at both state (endangered) and federal (threatened) levels. Neither the giant
sand-treader cricket nor the Palm Springs round-tailed ground squirrel is formally listed at
either state or federal levels.
Sightings of Coachella Valley fringe-toed lizard and Palm Springs round-tailed ground
squirrel are south of the Project area and south of Highway 111. Records of Coachella Valley
fringe-toed lizard and the giant sand-treader cricket are north of the Project area and
urbanized sections of La Quinta.
The U.S. Fish and Wildlife Service was consulted for information as to which species should
be analyzed for this document. The list they provided is included in Appendix A. Species that
were on the list included Coachella Valley fringe-toed lizard, Casey’s June beetle, desert
pupfish (Cyprinodon macularius), and peninsular bighorn sheep (Ovis Canadensis nelsoni).
All of these species are analyzed for their potential to occur within Table 3-1 below.
All of the special-status animal species analyzed for the Project, including those recorded
within five miles of the BSA, are summarized in Table 3-1. These designations are based
on their current distribution, habitat requirements, and information concerning land use
within the vicinity of the BSA. Based on surveys discussed in Section 2.2 and the
rationale discussed for each species in Table 3-1, there is suitable habitat for five species
within the BSA: burrowing owl, loggerhead shrike, Earthquake Merriam’s kangaroo rat
(Dipodomys merriami bangsi), pallid bat (Antrozous pallidus), and western yellow bat
(Lasiurus xanthinus). Of these species, only the burrowing owl poses a potential
constraint for the Project.
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Table 3-1: Regional Plant and Wildlife Species of Concern
Scientific Name Common Name Status General Habitat Description
Habitat
Present/
Absent Rationale
Plants
Abronia villosa var.
aurita
Chaparral sand
verbena
US:--
CA:--
CNPS 1B
Sandy areas within desert scrub habitats. A Not likely to occur. The BSA contains
disturbed land typical of urban areas. Some
small potential occurs within the CVSWC
areas. Surveys for this species were
conducted and were negative.
Astragalus
lentiginosus var.
coachellae
Coachella Valley
milk vetch
US:FE
CA:--
CNPS 1B
Occurs in sand dunes within the Coachella
Valley.
A Not likely to occur. The BSA contains
disturbed land typical of urban areas. Some
small potential occurs within the CVSWC
areas. Surveys for this species were
conducted and were negative.
Ditaxis claryana Glandular ditaxis US:--
CA:--
CNPS 2
Sandy soils in creosote bush scrub within the
Coachella Valley.
A Not likely to occur. No suitable habitat within
the BSA.
Ditaxis serrata var.
californica
California ditaxis CNPS 3 Natural washes and canyons within the
Coachella Valley.
A Not likely to occur. No suitable habitat within
the BSA.
Nemacaulus
denudata var.
gracilis
Slender
cottonheads
CNPS 2 Coastal dunes, Sonoran desert scrub, desert
dunes.
A Not likely to occur. No suitable habitat within
the BSA.
Birds
Polioptila melanura Black-tailed
gnatcatcher
US: --
CA: --
Inhabits many forms of desert scrub, mesquite
bosque, and other desert habitats of the
southwest.
A Not likely to occur. No suitable habitat within
the BSA.
Athene cunicularia Burrowing owl US:BCC
CA:SSC
Uses large rodent burrows or other burrows in
disturbed areas, grasslands, prairies, and
agricultural areas.
P Moderate potential to occur. Suitable
habitat occurs within the BSA in the disturbed
areas.
Falco mexicanus Prairie falcon US: –
CA:WL
Inhabits extensive open spaces in deserts,
prairies and grasslands. Breeds in cliff areas
within a mile of foraging areas.
A Not likely to occur. No suitable habitat within
the BSA.
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Table 3-1: Regional Plant and Wildlife Species of Concern
Scientific Name Common Name Status General Habitat Description
Habitat
Present/
Absent Rationale
Lanius ludovicianus loggerhead shrike US: BCC
CA: SSC
Nests in broken woodlands, savannah,
pinyon-juniper, Joshua tree, and riparian
woodlands, desert oases, scrub, and washes.
Prefers open country for hunting, with perches
for scanning, and fairly dense shrubs and
brush for nesting.
A Low potential to occur. Minimally suitable
habitat exists within the BSA.
Toxostoma lecontei Le Conte’s
thrasher
US:--
CA: SSC
Found in desert washes within dune areas,
desert scrub and other desert habitats.
A Not likely to occur. No suitable habitat within
the BSA. Although it is a wash, the habitat is
too disturbed for this species.
Toxostoma crissale Crissal thrasher US:--
CA: SSC
Desert washes and desert riparian thickets,
and palm oases.
A Not likely to occur. No suitable habitat within
the BSA. Although it is a wash, the habitat is
too disturbed for this species.
Reptiles
Uma inornata Coachella Valley
fringe-toed lizard
US:FE
CA:ST
May be found in low-elevation coastal scrub,
chaparral, and valley-foothill hardwood;
prefers sandy washes with patches of brush
and rocks.
P Not likely to occur. No suitable habitat within
the BSA.
Phrynosoma mccallii Flat-tailed horned
lizard
US:--
CA:CE
Fine sand habitats (such as dunes) within the
Imperial and Coachella Valleys.
P Not likely to occur. No suitable habitat within
the BSA.
Amphibians
Batrachoseps major
aridus
Desert slender
salamander
US:FE
CA:SE
Inhabits palm oases associated with springs
coming off of the Santa Rosa Mountains.
Known only from Hidden Palms Canyon and
Guadalupe Canyon. Thought to possibly be
extinct.
A Not likely to occur. No suitable habitat within
the BSA.
Mammals
Dipodomys merriami
collinus
Earthquake
Merriam’s
kangaroo rat
US: --
CA: --
Found in sandy soils, among rocks, in clays
and gravel areas. Habitat requirements for
this species are less rigid than many of its
close relatives.
A Low potential to occur. Suitable habitat is
present within the BSA; however, the habitat
is highly disturbed and unlikely to provide for a
sustainable population of this species.
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Table 3-1: Regional Plant and Wildlife Species of Concern
Scientific Name Common Name Status General Habitat Description
Habitat
Present/
Absent Rationale
Antrozous pallidus pallid bat US:--
CA:SSC
May be found in rocky, mountainous areas
and near water. Found in a variety of habitats,
from scattered desert scrub, grassland, shrub
land, woodland, and forests, from sea level
through mixed conifer. In addition, found over
more open, sparsely vegetated grasslands,
and seem to prefer to forage in the open.
Commonly found roosting in bridges.
P Moderate potential to occur. Although the
vegetation is disturbed, ruderal areas adjacent
to the BSA may provide foraging opportunities
for this species. May roost in trees, buildings,
and bridges within and near BSA.
Nyctinomops
femorosaccus
pocketed free-
tailed bat
US:--
CA:SSC
Found in the lower Colorado Desert and
coastal areas of southern California, but are
known as far north as Los Angeles and
southern San Bernardino counties.
Associated with arid lowland areas,
particularly desert canyons, and creosote
bush and chaparral habitats. Day roosts
primarily in crevices in cliff faces and
boulders, although has been found in caves
and buildings.
A Not likely to occur. No suitable habitat within
the BSA.
Lasiurus xanthinus western yellow bat US:--
CA:SSC
Found in fan palm oases and associated
riparian habitats in the Colorado Desert of
California. Appears to be expanding its range
northward in association with ornamental
palms. Range extends into Los Angeles and
southern San Bernardino counties.
P Moderate potential to occur. This species is
not known to use bridges for roosting;
however, the BSA contains ornamental palms
within and adjacent to the BSA.
Taxidea taxus American badger US:--
CA:SSC
Drier open stages of shrub, forest, and
herbaceous habitats, with friable soils; needs
sufficient food and open, uncultivated ground;
digs burrows.
A Not likely to occur. No suitable habitat within
the BSA.
Xerospermophilus
tereticaudus chlorus
Palm Springs
round-tailed ground
squirrel
US:FT
CA:SE
Mesquite and creosote-dominated sand dune
areas, creosote bush scrub, creosote-palo
verde scrub, and alkali scrub plant
communities.
A Not likely to occur. No suitable habitat within
the BSA.
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Table 3-1: Regional Plant and Wildlife Species of Concern
Scientific Name Common Name Status General Habitat Description
Habitat
Present/
Absent Rationale
Perognathus
longimembris bangsi
Palm Springs
pocket mouse
US:--
CA:SSC
May be found in lower elevation grasslands
and coastal sage communities; prefers open
ground with fine sandy soils.
A Not likely to occur. No suitable habitat within
the BSA.
Ovis Canadensis
nelson
Peninsular bighorn
sheep
US:--
CA: FP
Occurs within rocky habitats of the eastern
side of the San Jacinto and Santa Rosa
Mountains.
A Not likely to occur. No suitable habitat within
the BSA.
Fish
Cyprinodon
macularius
Desert pupfish US: --
CA:--
Occurs within seeps, springs, and slow-
moving streams within the Salton Sea basin.
A Not likely to occur. No suitable habitat within
the BSA.
Invertebrates
Dinacoma caseyi Casey’s June
beetle
US:FE
CA:--
Found only in and around palm oases of the
mountains west of the Coachella Valley.
Known currently only from Palm Canyon
Wash south of Palm Springs.
A Not likely to occur. No suitable habitat within
the BSA.
Macrobaenetes
valgum
Coachella giant
sand-treader
cricket
US:--
CA:--
Associated with sand dune areas. A Not likely to occur. No suitable habitat within
the BSA.
US: Federal Classifications
FE Federal Endangered
FT Federal Threatened
PE Proposed Endangered
PT Proposed Threatened
FC Federal Candidate
BCC Bird of Conservation Concern
CNPS: California Native Plant Society Classifications
1A Plants presumed extinct in California
1B Plants considered by CNPS to be rare, threatened, or endangered in California and
elsewhere
2 Plants considered by CNPS to be rare, threatened, or endangered in California, but
more common elsewhere
3 Plants considered by CNPS to require more information
CA: State Classifications
SE State Endangered
ST State Threatened
SR State Rare
SSC California Species of Concern
Habitat Present/Absent within the BSA
P Present
A Absent
CH Critical Habitat
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Chapter 4 – Results: Biological Resources, Discussion of
Impacts and Mitigation
4.1 Habitats and Natural Communities of Special Concern
4.1.1 WATERS OF THE UNITED STATES.
4.1.1.1 Survey Results
Within the BSA, the CVSWC was determined to be a potential jurisdictional Waters of
the U.S. as set forth in 33 CFR 328.33(a). There was also a potential jurisdictional
wetland area found to the west of Dune Palms Road, associated with a pipe outlet
conveying urban runoff. The jurisdictional portion of the channel accounts for a total of
2.20 acres and 490 linear feet of intermittent streambed and 0.28 acre and 15 linear feet
of wetland within the BSA (Exhibit 4.1).
4.1.1.2 Project Impacts
In total, USACE jurisdiction features being impacted consist entirely of intermittent
stream within a previously disturbed drainage channel. The construction of this feature
was considered an authorized impact because it was constructed prior to the Clean Water
Act. Typically all impacts to previously authorized constructed features are considered to
be temporary impacts. Based on preliminary engineering for the Project, there would be
0.05 acre and 12 linear feet of temporary impacts and 0.02 acre and five linear feet of
permanent impacts to USACE jurisdictional areas. The impacts below are depicted
showing both temporary and permanent impacts for each project alternative (Table 4-1).
Table 4-1: Potential USACE Jurisdictional Area Impacts
Geomorphic Feature Impacts (Acres/Linear Feet)
Temporary Permanent
Intermittent Stream
(CVSWC) 0.05/12 0.02/5
Wetland 0/0 0/0
Total 0.05/12 0.02/5
Before construction activities begin for the proposed project, the following approvals/
permits must be obtained or determined not applicable by the Department through
additional coordination with the applicable Federal and State resource agencies:
• Streambed Alteration Agreement pursuant to California Fish and Game Code
Section 1602;
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• USACE Nationwide Permit pursuant to CWA Section 404; and RWQCB 401 Water
Quality Certification pursuant to CWA Section 401.
4.1.1.3 Avoidance and Minimization Efforts
Waters of the U.S. impacts have been avoided to the maximum extent practicable by
project design to avoid work that fills these areas. Temporary impacts are necessary to
divert traffic away from the location of the permanent bridge during the construction
period. The temporary impact areas would be restored to existing topography after
construction has been completed. The location of the permanent bridge structure would
coincide with the existing location of the low-flow crossing within Dune Palms Road.
The following measures are proposed to reduce and minimize impacts:
• Project construction activities are anticipated to occur through the rainy season.
Should surface water flow occur through the project area at any point, then the
contractor will initiate appropriate BMPs. Groundwater levels are below the level of
anticipated Project excavations. Construction activities within the CVSWC will be
designed/conducted to maintain downstream flow conditions.
• ESAs will be incorporated into the plans and specifications for the project so that the
contractor is aware of the limits of allowable site access and disturbance.
• BMPs will be implemented to preserve downstream water quality.
• All drainages temporarily impacted during construction will be returned to their
original contours at the end of project activities.
• Measures will be adopted to prevent potential pollutants from entering the
watercourse. Construction materials and debris will not be stored in drainages to
prevent spills/runoff from entering jurisdictional areas.
4.1.1.4 Compensatory Mitigation
Specific mitigation for the temporary impacts to waters of the U.S. is not being proposed
due to the disturbed nature of the habitats to be impacted. Additional mitigation, if
required, will be conducted in the context of the regulatory permitting process for the
Project. No mitigation of temporary impacts to unvegetated channels within the study
corridor is being proposed other than re-contouring of the area being impacted to match
pre-project conditions. For permanent impacts, no mitigation is proposed because the
Project impacts are to highly disturbed areas and the Project would remove the concrete
low-flow crossing that is currently in place and re-contour that area to a natural condition.
The Project would have a net beneficial impact due to a net reduction in the impact
footprint of the road crossing.
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4.1.3.5 Cumulative Impacts
Cumulative effects include the effects of future state, tribal, local, or private actions that
are reasonably certain to occur in the study corridor. Many of the actions that are
reasonably certain to occur within this project vicinity will not be subject to federal or
state review or consultations for plant or wildlife species because they occur within
heavily urbanized zones that support limited natural habitat. With incorporation of the
avoidance and minimization measures identified in Section 4.1.3.2 and permit conditions
that would be identified during permit coordination with USACE, CDFW, and RWQCB,
no substantial cumulative impacts are anticipated.
4.1.2 WATERS OF THE STATE
4.1.2.1 Survey Results
CDFW jurisdiction includes the entirety of the USACE jurisdictional features cited
above. Prior to project implementation, a 1602 Streambed Alteration Agreement from the
CDFW would be required for impacts to jurisdictional areas.
Based on the results of this study presented in Section 4, potential RWQCB jurisdiction
was determined to include the entire impacted Waters of the State located within the
Project area. Prior to issuing a 404 permit for the project, a 401 water quality certification
would be required for impacts to the jurisdictional areas.
4.1.2.2 Project Impacts
Based on preliminary engineering for the Project, there would be 0.05 acre and 12 linear
feet of temporary impacts and 0.02 acre and five linear feet of permanent impacts to
CDFW jurisdictional areas. Permanent and temporary effects for each alternative are
summarized in Table 4-2.
Table 4-2: Potential CDFW and RWQCB Jurisdictional Area Impacts
Geomorphic Feature Impacts (Acres/Linear Feet)
Temporary Permanent
Intermittent Stream
(CVSWC) 0.05/12 0.02/5
Wetland 0/0 0/0
Total 0.05/12 0.02/5
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4.1.2.3 Avoidance and Minimization Efforts
Waters of the State impacts have been avoided to the maximum extent practicable by
project design to minimize work that fills these areas. The minimization efforts being
proposed for impacts to CDFW and RWQCB jurisdiction duplicate those used to mitigate
impacts to USACE jurisdiction.
4.1.2.4 Compensatory Mitigation
Specific mitigation for the temporary impacts to waters of the state is not being proposed
due to the disturbed nature of the habitats to be impacted. The areas to be impacted would
be restored to their existing topographic grade. See Section 4.1.2 for details. Additional
mitigation, if required, will be conducted in the context of the regulatory permitting
process for the Project. No mitigation is being proposed because the Project impact area
is highly disturbed and the existing low flow crossing would be removed after
construction has been completed, leading to a net beneficial impact for the Project.
4.1.2.5 Cumulative Impacts
Cumulative effects include the effects of future state, tribal, local, or private actions that
are reasonably certain to occur in the study corridor. Many of the actions that are
reasonably certain to occur within this project vicinity will not be subject to federal or
state review or consultations for plant or wildlife species because they occur within
heavily urbanized zones that support limited natural habitat. With incorporation of the
avoidance and minimization measures identified in Section 4.1.3.2 and permit conditions
that would be identified during permit coordination with USACE, CDFW, and RWQCB,
no substantial cumulative impacts are anticipated.
Exhibit 4.1Jurisdictional Delineation
Map Date: 6/17/2015
Photo Source: Esri
2014-173 La Quinta Dune PalmsLocation: N:\2014\2014-173 La Quinta Dune Palms\MAPS\Wetland_Mapping\Wetland_Delineation\v1\LQDP_JD_V1.mxd (MAG, DW)-dwagnon 6/17/2015 !>!>
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Existing Low Flow Crossing
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4.2 Special Status Plant Species
During 2015 focused biological surveys conducted for rare plant species within the
Project area no sensitive plant species were noted. Prior to the survey, during the
literature search, some special-status plants with a moderate potential to occur were
identified, including chaparral sand verbena. Coachella Valley milk vetch was not
expected to occur, but due to its level of sensitivity the survey period encompassed the
blooming period for this plant as well as several others.
4.2.1 COACHELLA VALLEY MILK VETCH
The Coachella Valley milk vetch is a Federal endangered species that is found only
within sand dune habitat areas within the Coachella Valley. It blooms between February
and May. At reference populations that were checked in 2015, the plants began to bloom
in March.
Suitable habitat is comprised of sandy soils within desert dunes and Sonoran desert scrub
habitat areas (CNPS Online Inventory). The species is strongly associated with active,
stabilized, and shielded sandy substrates (Sanders and Thomas Olsen Associates 1996,
White 2004). These areas typically maintain a perennial plant cover of less than 50
percent. Associated plants include evergreen or deciduous shrubs, scattered low annuals,
and perennial grasses.
The closest known population of this plant species is north of the Project area within the
outskirts of Palm Desert, in sand dune areas. The closest Critical Habitat for this species
is mapped north of I-10.
4.2.1.1 Survey Results
No Coachella Valley milk vetch plants were observed within the Project area.
4.2.1.2 Project Impacts
There is no suitable habitat for the Coachella Valley milk vetch within the BSA. There
would also be no impact to the species Critical Habitat with the Project. No impacts to
the species are anticipated.
4.2.1.3 Avoidance and Minimization Efforts
It is not anticipated that the species would occur within the project footprint and no
impacts are anticipated due to the proposed Project. No avoidance and minimization
efforts are therefore proposed.
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4.2.1.4 Compensatory Mitigation
No compensatory mitigation would be required for this species because it is not expected
to occur within the project footprint.
4.2.1.5 Cumulative Impacts
There is no suitable habitat for the species, and it not expected to occur within the project
footprint. The proposed project would have no cumulative effects on the Coachella
Valley milk vetch.
4.2.3 OTHER SENSITIVE PLANT SPECIES
Other special-status species include all other plant species of special interest at the state
or federal level. None of the other special-status plant species is likely to occur within the
BSA. The BSA is highly disturbed, is directly adjacent to heavily developed areas, and
provides limited potential for habitat for other special-status plant species.
4.2.3.1 Survey Results
During rare plant surveys conducted in 2015, no other sensitive plant species were
observed within the BSA.
4.2.3.2 Project Impacts
No impacts from the project are anticipated at this time to other sensitive plant species.
With incorporation of the avoidance measures identified below, no substantial impacts to
other special-status plant species are anticipated.
4.2.3.3 Avoidance and Minimization Efforts
Although it is not anticipated that other special-status plant species will occur within the
Project footprint, due to the seasonal and annual variability of the species and related
climatic conditions and the potential passage of time between environmental approval
and initiation of construction activities, the following measure is required to
minimize/avoid any potential effects and ensure the opportunity for their protection prior
to construction disturbance:
If construction of the Project is delayed more than one (1) year from the time of the
current botanical survey, a botanical reassessment survey focused on CNPS species
within the proposed construction disturbance areas shall be conducted by a qualified
botanist during the appropriate flowering season(s) at least 1-year prior to initiation of
construction activities. If CNPS species are observed during the reassessment survey,
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then plant specimens shall be flagged and the City will be notified. Ground-disturbing
activities will not occur within 100 ft. of the location for 30 days to allow the City to
coordinate with CDFW regarding collection or relocation, as applicable, in accordance
with California Fish and Game Code Sections 1900-1913.
4.2.3.4 Compensatory Mitigation
No compensatory mitigation would be required for potential effects on other special-
status plant species. There is no suitable habitat for these species, and they are not
expected to occur within the project footprint. If other special-status plant species are
discovered within the project footprint during future surveys, the City would coordinate
with CDFW regarding their collection or relocation in accordance with California Fish
and Game Code Sections 1900-1913.
4.2.3.5 Cumulative Impacts
There is no suitable habitat for these species, and they are not expected to occur within
the project footprint. The proposed project would not contribute to cumulative effects on
other special-status species.
4.3 Special Status Animal Species Occurrences
Section 2.3 contains descriptions of the dates and results of the biological surveys
conducted for the project to assess potential presence of sensitive species and species
with protection measures assigned through Federal, State or local laws. Habitat
evaluations were made for burrowing owl, Palm Springs round-tailed ground squirrel,
and other sensitive species.
In addition, the USFWS identified the potential for four listed species to occur within the
study corridor. These additional listed species include desert pupfish, Coachella Valley
fringe-toed lizard, Casey’s June beetle, and peninsular bighorn sheep. None of these
species are expected to occur within the Project area or its environs.
4.3.1 DESERT PUPFISH
The desert pupfish is a small fish in Family Cyprinodontidae that historically occurred in
the deserts of southern California and Arizona within pools of permanent water and
streams. Their distribution is highly limited and known from only a few sites in the
region of the Salton Sea and Coachella Valley. Desert pupfish critical habitat does not
occur within the vicinity of the BSA.
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4.3.1.1 Survey Results
No desert pupfish surveys were conducted because the species is not expected to occur
within the study corridor due to a lack of habitat.
4.3.1.2 Project Impacts
Based on the analysis for this species, no desert pupfish would be impacted by the
proposed Project.
4.3.1.3 Avoidance and Minimization Efforts
No specific avoidance or minimization efforts are warranted for this species.
4.3.1.4 Compensatory Mitigation
No direct impact on the species is anticipated; therefore no compensatory mitigation is
required.
4.3.1.5 Cumulative Impacts
The species is not expected to occur within the project footprint, and the proposed Project
would not contribute to cumulative effects on the desert pupfish.
4.3.2 COACHELLA VALLEY FRINGE-TOED LIZARD
The Coachella Valley fringe-toed lizard is a sand-dwelling lizard species that is known
from several types of sandy habitat within the Coachella Valley. Although it can occur
near several vegetation types, it requires sandy areas to burrow and forage. Critical
habitat for this species occurs approximately five miles northwest of the BSA to the north
of I-10.
4.3.2.1 Survey Results
No fringe-toad lizard surveys were conducted because the species is not expected to
occur within the study corridor due to a lack of habitat.
4.3.2.2 Project Impacts
Based on the analysis for this species, no fringe-toed lizards would be impacted by the
proposed Project.
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4.3.2.3 Avoidance and Minimization Efforts
No specific avoidance or minimization efforts are warranted for this species.
4.3.2.4 Compensatory Mitigation
No direct impact on the species is anticipated; therefore no compensatory mitigation is
required.
4.3.2.5 Cumulative Impacts
The species is not expected to occur within the project footprint, and the proposed Project
would not contribute to cumulative effects on the fringe-toed lizard.
4.3.3 CASEY’S JUNE BEETLE
Casey’s June Beetle is a scarab beetle (Family Scarabaeidae). The beetle occurs within
palm tree oases along the southeastern edge of the San Jacinto and Santa Rosa Mountain
ranges. Casey’s June beetle critical habitat occurs within Palm Canyon south of Palm
Springs and approximately 15 miles northwest of the BSA.
4.3.3.1 Survey Results
No Casey’s J une beetle surveys were conducted because the species is not expected to
occur within the study corridor due to a lack of habitat.
4.3.3.2 Project Impacts
Based on the analysis for this species, no Casey’s June beetles would be impacted by the
proposed Project.
4.3.3.3 Avoidance and Minimization Efforts
No specific avoidance or minimization efforts are warranted for this species.
4.3.3.4 Compensatory Mitigation
No direct impact on the species is anticipated; therefore no compensatory mitigation is
required.
4.3.3.5 Cumulative Impacts
The species is not expected to occur within the project footprint, and the proposed Project
would not contribute to cumulative effects on the Casey’s June beetle.
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4.3.4 PENINSULAR BIGHORN SHEEP
Peninsular bighorn sheep are a large ungulate species that inhabits desert slopes of the
Peninsular Ranges in San Diego, Imperial and Riverside Counties. They occur on rocky
slopes, desert canyons, washes and alluvial fans. Bighorn sheep critical habitat has been
designated within the northeastern slopes of the San Jacinto and Santa Rosa Mountain
ranges, the closest section of which is three miles south of the BSA.
4.3.4.1 Survey Results
No Peninsular bighorn sheep surveys were conducted because the species is not expected
to occur within the study corridor due to a lack of habitat.
4.3.4.2 Project Impacts
Based on the analysis for this species, no bighorn sheep would be impacted by the
proposed Project.
4.3.4.3 Avoidance and Minimization Efforts
No specific avoidance or minimization efforts are warranted for this species.
4.3.4.4 Compensatory Mitigation
No direct impact on the species is anticipated; therefore no compensatory mitigation is
required.
4.3.4.5 Cumulative Impacts
The species is not expected to occur within the project footprint, and the proposed Project
would not contribute to cumulative effects on the bighorn sheep.
4.3.8 OTHER SENSITIVE ANIMAL SPECIES
Other special-status species include all other wildlife of species of special interest at the
State and Federal levels. Table 3-1 identifies all other special-status wildlife species with
the potential to occur within the BSA. The BSA is highly disturbed, directly adjacent to
urbanized areas, and provides limited habitat for special-status wildlife species.
4.3.8.1 Survey Results
All wildlife species observed during the surveys discussed in Section 2.2 were noted and
are included in the fauna compendium in Appendix B. No other special-status species
were observed during general biological surveys. Based on the habitat types and quality
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within the BSA, there is a low potential for loggerhead shrike and earthquake Merriam’s
kangaroo rat, and a moderate potential for burrowing owl, western yellow bat and pallid
bat to occur within the BSA. Areas with the highest potential for other special-status
species include the undeveloped CVSWC, the undeveloped parcel southeast of Dune
Palms Road, and in trees and shrubs within and adjacent to the BSA. Although not
specifically listed in Table 3-1 or observed during surveys, common raptors and other
nesting birds protected by the MBTA have a high potential to occur within shrubs and
trees within the BSA; however, no nests were observed within vegetation during biological
studies. No burrowing owl or sign of burrowing owl were observed within the Project area.
No focused surveys for other special-status wildlife species were completed for the
proposed Project.
4.3.8.2 Project Impacts
Areas to be temporarily affected due to construction activities include areas within
CVSWC to be used for a temporary bypass during construction, and temporary
construction access. The permanent impact include areas used for the construction of the
bridge columns.
Direct impacts to wildlife would include both temporary and permanent loss of habitat,
including areas used for nesting and for burrows by ground-dwelling mammals and
reptiles. Species that are relatively mobile (e.g., birds and many small mammals and
reptiles) would likely disperse into nearby areas. Some mortality of less mobile and
burrowing species may occur.
Temporary impacts would be limited to the construction period and include increased
noise levels and increased human disturbance. Construction noise may adversely affect
nesting birds, particularly if construction and vegetation clearing begins after the onset of
the nesting season; however, all vegetation clearing and nest removal would be
completed in accordance with the measures previously discussed, and no substantial
temporary effects on nesting birds are anticipated.
Indirect effects on wildlife beyond the BSA could result from impacts to water quality
during construction; however, these impacts would be avoided and minimized through
implementation of BMPs in accordance with the SWPPP. The SWPPP and anticipated
treatment BMPs are designed to minimize impacts on water quality and accommodate
and treat runoff from the road surface. Incorporation of BMPs into all phases of the
Project would ensure no substantial adverse effects on wildlife associated with
construction or operational effects on water quality. No substantial adverse indirect
impacts to wildlife beyond the BSA are expected as a result of the project. Additional
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common indirect effects associated with construction include noise and glare, invasive
species, increased dust generation, mortality of displaced wildlife.
Nesting Birds and Swallows
Raptors and migratory birds potentially using plant species within and adjacent to the
BSA could be affected by their removal and/or proximity to construction activities.
Project impacts to nesting birds are primarily limited to the removal of vegetation within
the BSA and ground disturbance (for ground-nesting species such as burrowing owl). No
raptor nests or other nests in vegetation within the BSA were observed during biological
surveys. Permanent impacts from loss of vegetation communities are limited to primarily
disturbed and ornamental species that do not provide any substantial value as wildlife
habitat. Other than indirect impacts through loss of vegetation, no other effects on
wildlife are expected.
Burrowing Owls
No burrowing owls were observed within the study area during the general biological
surveys but a burrowing owl habitat assessment was completed during 2015. Burrowing
owl habitat is considered to consist of the southeast corner of the BSA, outside of the
CVSWC, and consisting of 1.97 acres of habitat area located in an undeveloped parcel
outside of the main channel, being considered as a CSA. There is no identified burrowing
owl habitat within the proposed bridge work areas for the temporary or permanent
impacts for the road construction. If the vacant lot is used as a CSA, we recommend that
preconstruction burrowing owl surveys would be completed within 30 days prior to ground
disturbance or site preparation within the CSA.
If burrowing owls are observed during pre-construction surveys, and are not avoidable, then a
burrowing owl mitigation plan would be developed and approved by CDFW prior to Project
construction. Possible mitigation measures may include passive relocation and burrowing
owl exclusion from burrows during the non-breeding season. With implementation of the
proposed measures, no substantial effects on burrowing owls are anticipated.
Bats
It is though that certain bat species, including the western yellow bat and pallid bat, have
a moderate potential to use the CVSWC channel areas and surrounding urban areas. Bat
use is expected to be temporary and consist of foraging use primarily or temporary
resting on ornamental vegetation or structures. Because bat use of the BSA is anticipated
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to be limited, and no permanent roost sites are identified within the Project area, no
substantial project effects on bats are anticipated.
4.3.8.3 Avoidance and Minimization Efforts
Nesting Bird Species
To avoid effects to nesting birds, vegetation removals would occur outside of the nesting
bird season (i.e., February 15–August 31) to the maximum extent practicable. In the
event that vegetation clearing is necessary during the nesting season, the contractor will
have a qualified biologist conduct a preconstruction survey within 300 ft. of construction
areas no more than 30 days prior to construction at the location to identify the locations
of nests (if any). A qualified biologist is one that has surveyed for nesting bird species
within the Coachella Valley previously and has at least two years of prior nesting bird
survey experience. Should nesting birds be found, an exclusionary buffer will be
established by the qualified biologist around each nest site. This buffer will be a distance
from the construction activity based on the nest location, surrounding existing
disturbances and the species of bird that is nesting. The buffer will be clearly marked in
the field by construction personnel under guidance of the contractor’s qualified biologist,
and construction or clearing will not be conducted within this zone until the qualified
biologist determines that the young have fledged or the nest is no longer active.
The qualified biologist will monitor the nests on a weekly basis to ensure that
construction activities do not disturb or disrupt nesting activities. If the qualified biologist
determines that construction activities are disturbing or disrupting nesting activities, then
the biologist will notify the City. Responses may include, but are not limited to,
increasing the size of the exclusionary buffer, curtailing nearby work activities, turning
off vehicle engines and other equipment whenever possible to reduce noise, installing a
protective noise barrier between the nest and the construction activities, and/or working
in other areas until the young have fledged.
Burrowing Owls
To ensure that any burrowing owl that may occupy the Project area are not affected by
construction activities, the contractor will be required to have preconstruction burrowing
owl surveys conducted by a qualified biologist within 30 days prior to any phase of
construction, including staging, in the areas identified as potential burrowing owl habitat.
These preconstruction surveys are also required to comply with the MBTA and the
California Fish and Game Code. If any of the preconstruction surveys determine that
burrowing owls are present, one or more of the following mitigation measures will be
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required: (1) avoidance of active nests/burrows and surrounding buffer area during
construction activities; (2) passive relocation of individual owls; and (3) preservation of
on-site habitat with long-term conservation value for the owl. Because any presence of
burrowing owl must be documented and mitigation measures must be developed in
concert with the CDFW, the contractor’s qualified biologist, the City and CDFW will
determine which specific measure(s) will be implemented.
4.3.8.4 Compensatory Mitigation
Due to the relatively low level of sensitivity of the other sensitive species that could
occur within the Project area, no compensatory measures are proposed other than those
specified above.
4.3.8.5 Cumulative Impacts
With incorporation of the avoidance and minimization measures previously discussed, no
substantial cumulative effects on other special-status species are expected.
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Chapter 5 – Conclusions and Regulatory Determinations
5.1 Federal Endangered Species Act Consultation Summary
No federally listed species or critical habitat for a federally-listed species was determined
to have a potential to occur within the BSA. The species list for this project was
requested and received in March 2015.
5.2 Essential Fish Habitat Consultation Summary
No federal fisheries or essential fish habitat resources are present within the proposed
study corridor, and no consultation with National Marine Fisheries Service is required.
5.3 California Endangered Species Act Consultation Summary
No species listed pursuant to the CESA occur within or adjacent to the BSA, and no
impacts on state-listed species are expected.
5.4 Wetlands and Other Waters Coordination Summary
In 2015, a delineation of jurisdictional waters and wetlands within the Project area
revealed the presence of an intermittent stream and wetland within the BSA. The
Jurisdictional Delineation Report is provided in Appendix D.
The final determination of the limits of the jurisdictional areas within the BSA and
whether mitigation will be required for such impacts is ultimately subject to the
discretion of the agencies (i.e., CDFW, USACE, and RWQCB) during the federal and
state regulatory permitting processes. Based on preliminary engineering for the Project,
there would be 0.05 acre and 12 linear feet of temporary impacts and 0.02 acre and five
linear feet of permanent impacts to USACE, CDFW, and RWQCB jurisdictional areas.
As previously discussed in Sections 4.1.1 and 4.1.2, impacts to jurisdictional areas would
occur during construction of the proposed Project. Before construction for the proposed
project begins, the following permits must be obtained or determined not applicable
through additional coordination with the applicable federal and state resource agencies:
Section 404 authorization from USACE (Linear Transportation Projects), Section 401
Water Quality Certification from RWQCB, and Section 1602 Streambed Alteration
Agreement from CDFW. Measures to address unavoidable impacts will be negotiated
with resource agencies and incorporated into the environmental commitments record for
the project before construction begins.
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5.5 Invasive Species
Invasive, exotic plant species exist within the BSA. Exotic species are typically more
numerous adjacent to roads and developed areas and frequently border the ornamental
landscape. In the past, these areas within the BSA supported native plant communities.
Consequently, some native plants are often found intermixed with exotic species within
the BSA.
Seven (7) exotic plants on Cal-IPC’s California Invasive Plant Inventory were identified.
Of these species, three have an overall high rating and four have a moderate rating.
Invasive species that have severe ecological impacts are given a high rating. Within the
BSA, species with a high rating are castor bean, tamarisk, and Russian thistle.
In compliance with EO 13112, and subsequent guidance from FHWA, the landscaping
and erosion control included in the project will not include species listed on either the
Federal or the State of California Noxious Weed List. In areas of particular sensitivity
(i.e., near or adjacent to drainages) extra precautions would be taken if invasive species
are found in or adjacent to these areas. This would include the inspection and cleaning of
construction equipment and eradication strategies, as needed should an invasion occur.
As discussed in Chapter 3, no substantial populations of invasive wildlife have been
documented in the BSA. House sparrows, rock pigeons, and European starlings, as well
as Virginia opossums and feral dogs and cats, are known to occur and are common in
urban areas throughout southern California. Due to their prevalence within urban
habitats, eradication of these species within the BSA would have no effect on the local or
regional populations. No measures for invasive wildlife are therefore proposed for the
Project.
5.6 Other
5.6.1 MIGRATORY BIRD TREATY ACT
Native bird species and their nests are protected under the MBTA (16 United States Code
[U.S.C.] 703- 712). The MBTA states that all migratory birds and their parts, including
eggs, nests, and feathers, are fully protected. The MBTA prohibits the take, possession,
import, export, transport, selling, purchase, barter, or offering for sale, purchase, or
barter, any migratory bird, its eggs, parts, and nests, except as authorized under a valid
permit.
EO 13186 (Responsibilities of Federal Agencies to Protect Migratory Birds) directs
Federal agencies “taking actions that have, or are likely to have, a measurable negative
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effect on migratory bird populations to develop and implement a Memorandum of
Understanding with the Fish and Wildlife Service that promotes the conservation of
migratory bird populations.” In accordance with EO 13186 and the provisions of the
MBTA, the following measures will be incorporated, as described also in Chapter 4:
Nesting Bird Species
To avoid effects to nesting birds, vegetation removals would occur outside of the nesting
bird season (i.e., February 15–August 31) to the maximum extent practicable. In the
event that vegetation clearing is necessary during the nesting season, the contractor will
have a qualified biologist conduct a preconstruction survey within 300 ft. of construction
areas no more than 30 days prior to construction at the location to identify the locations
of nests (if any). A qualified biologist is one that has surveyed for nesting bird species
within the Coachella Valley previously and has at least two years of prior nesting bird
survey experience. Should nesting birds be found, an exclusionary buffer will be
established by the qualified biologist around each nest site. This buffer will be a distance
from the construction activity based on the nest location, surrounding existing
disturbances and the species of bird that is nesting. The buffer will be clearly marked in
the field by construction personnel under guidance of the contractor’s qualified biologist,
and construction or clearing will not be conducted within this zone until the qualified
biologist determines that the young have fledged or the nest is no longer active.
The qualified biologist will monitor the nests on a weekly basis to ensure that
construction activities do not disturb or disrupt nesting activities. If the qualified biologist
determines that construction activities are disturbing or disrupting nesting activities, then
the biologist will notify the City. Responses may include, but are not limited to,
increasing the size of the exclusionary buffer, curtailing nearby work activities, turning
off vehicle engines and other equipment whenever possible to reduce noise, installing a
protective noise barrier between the nest and the construction activities, and/or working
in other areas until the young have fledged.
Burrowing Owls
To ensure that any burrowing owl that may occupy the Project area are not affected by
construction activities, the contractor will be required to have preconstruction burrowing
owl surveys conducted by a qualified biologist within 30 days prior to any phase of
construction, including staging, in the areas identified as potential burrowing owl habitat.
These preconstruction surveys are also required to comply with the MBTA and the
California Fish and Game Code. If any of the preconstruction surveys determine that
burrowing owls are present, one or more of the following mitigation measures will be
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required: (1) avoidance of active nests/burrows and surrounding buffer area during
construction activities; (2) passive relocation of individual owls; and (3) preservation of
on-site habitat with long-term conservation value for the owl. Because any presence of
burrowing owl must be documented and mitigation measures must be developed in
concert with the CDFW, the contractor’s qualified biologist, the City and CDFW will
determine which specific measure(s) will be implemented.
5.6.2 WILD AND SCENIC RIVERS
There are no designated Wild and Scenic Rivers within the study corridor.
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Chapter 6 – References
CDFW (California Department of Fish and Game). 2003 (September). List of
California Terrestrial Natural Communities Recognized by the California
Natural Diversity Database. California Department of Fish and Game, Wildlife
and Habitat Data Analysis Branch. Sacramento, CA.
CNPS (California Native Plant Society). 2006. Inventory of Rare and Endangered
Plants (online edition, v6-05a). California Native Plant Society. Sacramento,
CA. Accessed on April 7 from http://www.cnps.org/inventory.
CNDDB (California Natural Diversity Database). 1999. Dodecahema leptoceras,
unpublished report, Natural Heritage Division, California Department of Fish
and Game, Sacramento, CA.
Hall, E. Raymond. 1981. The Mammals of North America, vols. I and II, 2nd ed. John
Wiley and Sons, Inc. New York, New York, USA. 1181.
Holland, R.F. 1986. Preliminary Descriptions of the Terrestrial Natural Communities
of California. Non-game Heritage Program. California Department of Fish and
Game. Sacramento, CA. Updated in 1992.
Lidicker, W.Z., Jr. 1960. An analysis of intraspecific variation in the kangaroo rat
Dipodomys merriami. University of California Publications in Zoology,
67:125-218.
Moyle, P.B. 1976. Inland fishes of California. University of California Press,
Berkeley, CA. 405 pp.
Moyle, P.B., R.M. Yoshiyama, J.E. Williams, and E.D. Wikramanayake. 1995. Fish
species of special concern in California. Second edition. California
Department of Fish and Game, Inland Fisheries Division, Rancho Cordova,
CA. iv + 272 pp.
Page, L.M. and B.M. Burr. 1991. A field guide to freshwater fishes: North America
north of Mexico. Houghton Mifflin Company, Boston, MA. 432 pp.
USDA (U.S. Department of Agriculture). 1971. Soil Survey: Riverside County,
California. Department of the Interior. U.S. Government Printing Office.
Washington, D.C.
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Zeiner, D.C., W.F. Laudenslayer, Jr., K.E. Mayer, and M. White. Editors. 1990.
California’s Wildlife. Volume 2. Birds. State of California, Department of Fish
and Game. Sacramento, CA. 731 pp.
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Appendix A – USFWS Species List
United States Department of the Interior
FISH AND WILDLIFE SERVICE
Carlsbad Fish and Wildlife Office
2177 SALK AVENUE - SUITE 250
CARLSBAD, CA 92008
PHONE: (760)431-9440 FAX: (760)431-5901
URL: www.fws.gov/carlsbad/
Consultation Code: 08ECAR00-2015-SLI-0306 March 26, 2015
Event Code: 08ECAR00-2015-E-00610
Project Name: La Quinta Dune Palms Road
Subject:List of threatened and endangered species that may occur in your proposed project
location, and/or may be affected by your proposed project
To Whom It May Concern:
The enclosed species list identifies threatened, endangered, and proposed species, designated
critical habitat, and candidate species that may occur within the boundary of your proposed
project and/or may be affected by your proposed project. The species list fulfills the
requirements of the U.S. Fish and Wildlife Service (Service) under section 7(c) of the
Endangered Species Act (Act) of 1973, as amended (16 U.S.C. 1531 ).et seq.
New information based on updated surveys, changes in the abundance and distribution of
species, changed habitat conditions, or other factors could change this list. Please feel free to
contact us if you need more current information or assistance regarding the potential impacts to
federally proposed, listed, and candidate species and federally designated and proposed critical
habitat. Please note that under 50 CFR 402.12(e) of the regulations implementing section 7 of
the Act, the accuracy of this species list should be verified after 90 days. This verification can
be completed formally or informally as desired. The Service recommends that verification be
completed by visiting the ECOS-IPaC website at regular intervals during project planning and
implementation for updates to species lists and information. An updated list may be requested
through the ECOS-IPaC system by completing the same process used to receive the enclosed
list.
The purpose of the Act is to provide a means whereby threatened and endangered species and
the ecosystems upon which they depend may be conserved. Under sections 7(a)(1) and 7(a)(2)
of the Act and its implementing regulations (50 CFR 402 ), Federal agencies are requiredet seq.
to utilize their authorities to carry out programs for the conservation of threatened and
endangered species and to determine whether projects may affect threatened and endangered
species and/or designated critical habitat.
A Biological Assessment is required for construction projects (or other undertakings having
similar physical impacts) that are major Federal actions significantly affecting the quality of the
human environment as defined in the National Environmental Policy Act (42 U.S.C. 4332(2)
(c)). For projects other than major construction activities, the Service suggests that a biological
evaluation similar to a Biological Assessment be prepared to determine whether the project may
affect listed or proposed species and/or designated or proposed critical habitat. Recommended
contents of a Biological Assessment are described at 50 CFR 402.12.
If a Federal agency determines, based on the Biological Assessment or biological evaluation,
that listed species and/or designated critical habitat may be affected by the proposed project, the
agency is required to consult with the Service pursuant to 50 CFR 402. In addition, the Service
recommends that candidate species, proposed species and proposed critical habitat be addressed
within the consultation. More information on the regulations and procedures for section 7
consultation, including the role of permit or license applicants, can be found in the "Endangered
Species Consultation Handbook" at:
http://www.fws.gov/endangered/esa-library/pdf/TOC-GLOS.PDF
Please be aware that bald and golden eagles are protected under the Bald and Golden Eagle
Protection Act (16 U.S.C. 668 ), and projects affecting these species may requireet seq.
development of an eagle conservation plan
(http://www.fws.gov/windenergy/eagle_guidance.html). Additionally, wind energy projects
should follow the wind energy guidelines (http://www.fws.gov/windenergy/) for minimizing
impacts to migratory birds and bats.
Guidance for minimizing impacts to migratory birds for projects including communications
towers (e.g., cellular, digital television, radio, and emergency broadcast) can be found at:
http://www.fws.gov/migratorybirds/CurrentBirdIssues/Hazards/towers/towers.htm;
http://www.towerkill.com; and
http://www.fws.gov/migratorybirds/CurrentBirdIssues/Hazards/towers/comtow.html.
We appreciate your concern for threatened and endangered species. The Service encourages
Federal agencies to include conservation of threatened and endangered species into their project
planning to further the purposes of the Act. Please include the Consultation Tracking Number in
the header of this letter with any request for consultation or correspondence about your project
that you submit to our office.
Attachment
2
http://ecos.fws.gov/ipac, 03/26/2015 04:34 PM
1
Official Species List
Provided by:
Carlsbad Fish and Wildlife Office
2177 SALK AVENUE - SUITE 250
CARLSBAD, CA 92008
(760) 431-9440
http://www.fws.gov/carlsbad/
Consultation Code: 08ECAR00-2015-SLI-0306
Event Code: 08ECAR00-2015-E-00610
Project Type: Bridge Construction / Maintenance
Project Name: La Quinta Dune Palms Road
Project Description: The Project entails replacement of a low-flow crossing over the Coachella
Valley Storm Channel with a new bridge.
Please Note: The FWS office may have modified the Project Name and/or Project Description, so it
may be different from what was submitted in your previous request. If the Consultation Code
matches, the FWS considers this to be the same project. Contact the office in the 'Provided by'
section of your previous Official Species list if you have any questions or concerns.
United States Department of Interior
Fish and Wildlife Service
Project name: La Quinta Dune Palms Road
http://ecos.fws.gov/ipac, 03/26/2015 04:34 PM
2
Project Location Map:
Project Coordinates: MULTIPOLYGON (((-116.2801235 33.7123061, -116.2753385
33.7121812, -116.2753374 33.70804, -116.2800592 33.7082542, -116.2801235 33.7082899, -
116.2801235 33.7123061)))
Project Counties: Riverside, CA
United States Department of Interior
Fish and Wildlife Service
Project name: La Quinta Dune Palms Road
http://ecos.fws.gov/ipac, 03/26/2015 04:34 PM
3
Endangered Species Act Species List
There are a total of 4 threatened or endangered species on your species list. Species on this list should be considered in
an effects analysis for your project and could include species that exist in another geographic area. For example, certain
fish may appear on the species list because a project could affect downstream species. Critical habitats listed under the
Has Critical Habitat column may or may not lie within your project area. See the Critical habitats within your
project area section further below for critical habitat that lies within your project. Please contact the designated FWS
office if you have questions.
Fishes Status Has Critical Habitat Condition(s)
Desert pupfish (Cyprinodon
macularius)
Population: Entire
Endangered Final designated
Insects
Casey's June Beetle (Dinacoma
caseyi)
Population: Entire
Endangered Final designated
Mammals
Peninsular bighorn sheep (Ovis
canadensis nelsoni)
Population: Peninsular CA pop.
Endangered Final designated
Reptiles
Coachella Valley Fringe-Toed lizard
(Uma inornata)
Population: Entire
Threatened Final designated
United States Department of Interior
Fish and Wildlife Service
Project name: La Quinta Dune Palms Road
http://ecos.fws.gov/ipac, 03/26/2015 04:34 PM
4
Critical habitats that lie within your project area
There are no critical habitats within your project area.
United States Department of Interior
Fish and Wildlife Service
Project name: La Quinta Dune Palms Road
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Appendix B – Flora and Fauna Species Compendium
Scientific Name Common Name
APOCYNACEAE DOGBANE FAMILY
Nerium oleander*Oleander
ASTERACEAE SUNFLOWER FAMILY
Ambrosia acanthicarpa Annual bur-sage
Ambrosia psilostachya Western ragweed
Helianthus annuus common sunflower
Palafoxia arida Spanish needles
Xanthium strumarium cocklebur
BORAGINACEAE BORAGE FAMILY
Emmenanthe penduliflora whispering bells
Tiquilia plicata plicate tiquilia
BRASSICACEAE MUSTARD FAMILY
Brassica sp.mustard
Brassica nigra*black mustard
CHENOPODIACEAE GOOSEFOOT FAMILY
Atriplex canescens four-wing saltbush
Chenopodium album*lamb's quarters
Salsola tragus*Russian thistle; tumbleweed
CUCURBITACEAE GOURD FAMILY
Cucurbita palmata coyote melon
Marah macrocarpa (= M. macrocarpus)wild cucumber
EUPHORBIACEAE SPURGE FAMILY
Croton setigerus (= Eremocarpus setigerus)dove weed
Ricinus communis*castor-bean
FABACEAE LEGUME FAMILY
Acacia sp.acacia
Melilotus indica*sourclover
Psorothamnus spinosus smoke tree
FAGACEAE OAK FAMILY
Quercus sp.oak
MYRTACEAE MYRTLE FAMILY
Eucalyptus sp.gum tree
NYCTAGINACEAE FOUR O'CLOCK FAMILY
ANGIOSPERMS (DICOTYLEDONS)
Abronia villosa sand verbena
Bougainvillea spectabilis bougainvillea
POLYGONACEAE BUCKWHEAT FAMILY
Rumex obtusifolius bitter dock
SOLANACEAE NIGHTSHADE FAMILY
Datura discolor jimson weed
Datura wrightii datura
Nicotiana glauca*tree tobacco
TAMARICACEAE TAMARISK FAMILY
Tamarix ramosissima*Mediterranean tamarisk
ZYGOPHYLLACEAE CALTROP FAMILY
Larrea tridentata creosote bush
Tribulus terrestris*puncture vine
POACEAE GRASS FAMILY
Cynodon dactylon*Bermuda grass
Pennisetum setaceum*fountain grass
TYPHACEAE CATTAIL FAMILY
Typha latifoilia broadleaf cattail
ANGIOSPERMS (MONOCOTYLEDONS)
* non-native species
Common Name Scientific Name
Ants Hymenoptera
Ant Hymenoptera
Birds Avians
black phoebe Sayornis nigricans
Eurasian-collared dove Streptopelia decaocto
northern mockingbird Mimus polyglottos
savannah sparrow Passerculus sandwichensis
common raven Corvus corax
california gull Larus californicus
rock dove Columba livia
great-tailed grackle Quiscalus mexicanus
Say's pheobe Sayornis saya
American kestrel Falco sparperius
European starling Sturnus vulgaris
greater roadrunner Geococcyx californianus
Anna's hummingbird Calypte anna
White-crowned sparrow Zonotrichia leucophrys
yellow-rumped warbler Dendroica coronata
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Appendix C – Jurisdictional Delineation Report
Dune Palms Road Low-Water Crossing Replacement Project
Jurisdictional Waters Delineation
City of La Quinta, California
Federal Aid Project No. BRLKS-5433(014)
September 2015
DUNE PALMS ROAD LOW-WATER CROSSING REPLACEMENT PROJECT
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Jurisdictional Delineation for the
Dune Palms Road Low-Water
Crossing Replacement Project
1.0 INTRODUCTION ................................................................................................. 1
1.1 PROJECT LOCATION ...................................................................................................... 2
1.2 PROJECT DESCRIPTION ................................................................................................. 2
2.0 REGIONAL SETTING ........................................................................................... 7
2.1 EXISTING CONDITIONS ................................................................................................. 7
2.2 VEGETATION COMMUNITIES ......................................................................................... 8
2.3 SOILS ............................................................................................................................. 9
2.4 WATERSHEDS .............................................................................................................. 10
3.0 METHODS ......................................................................................................... 13
3.1 U.S. ARMY CORPS OF ENGINEERS USACE JURISDICTION ........................................... 13
3.2 CALIFORNIA DEPARTMENT OF FISH AND WILDLIFE (CDFW) JURISDICTION .............. 16
3.3 REGIONAL WATER QUALITY CONTROL BOARD (RWQCB) JURISDICTION ................... 17
4.0 RESULTS .......................................................................................................... 18
4.1 POTENTIAL WATERS OF THE U.S. ............................................................................... 18
4.2 OTHER WATERS OF THE U.S. ...................................................................................... 19
4.3 CDFW JURISDICTION................................................................................................... 20
4.4 RWQCB JURISDICTION ................................................................................................ 20
4.4 PROJECT IMPACTS ....................................................................................................... 22
5.0 CONCLUSIONS AND RECOMMENDATIONS ....................................................... 25
5.1 CONCLUSIONS ............................................................................................................. 25
5.2 AVOIDANCE AND MINIMIZATION RECOMMENDATIONS .............................................. 25
7.0 REFERENCES .................................................................................................... 28
LIST OF TABLES
Table 1 – Classification of Wetland-Associated Plant Species ................................................. 15
Table 2 – Potential Waters of the U.S. ................................................................................ 18
Table 2 – Potential USACE Jurisdictional Area Impacts ......................................................... 22
LIST OF FIGURES
Exhibit 1.1 – Project Vicinity ................................................................................................ 5
Exhibit 1.2 – Project Location .............................................................................................. 6
Exhibit 2.1 – NRCS Soil Classifications ................................................................................. 11
Exhibit 2.2 – HUC 12 Watershed ......................................................................................... 12
Exhibit 4.1 – Jurisdictional Delineation ................................................................................ 21
Exhibit 4.2 – Jurisdictional Delineation Temporary Impacts…………………………………… ..... ……..23
Exhibit 4.3 – Jurisdictional Delineation Permanent Impacts…………………………………… ..... ……..24
CONTENTS
DUNE PALMS ROAD LOW-WATER CROSSING REPLACEMENT PROJECT
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LIST OF APPENDICES
Appendix A – Botanical Compendium
Appendix B – Arid West Wetland Determination Data Forms
Appendix C – Site Photographs
DUNE PALMS ROAD LOW-WATER CROSSING REPLACEMENT PROJECT
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September 2015 1
1.0 INTRODUCTION
The City of La Quinta Public Works Department (City) is proposing to replace the existing low-
water crossing spanning the Coachella Valley Storm Water Channel (CVSWC), also known as the
Whitewater River, at Dune Palms Road with an all-weather access and multimodal bridge
(Project) within the City of La Quinta, Riverside County, California. The CVSWC is a segment of
the Whitewater River that has been lined in many areas throughout the urbanized sections of
the channel with concrete to improve flood protection. The Whitewater River is an intermittent
stream within east Riverside County that is a part of the Whitewater River Watershed. The
Whitewater River headwaters are located in the San Bernardino Mountains, beginning on Mount
San Gorgonio and traveling southeast. The Whitewater River then turns into the CVSWC and is
channelized downstream from Point Happy in La Quinta near Highway 111 and Washington
Street. The channel then continues east and turns southeast where it terminates at the Salton
Sea, just south of the City of Mecca. It is the primary drainage course in Coachella Valley. The
CVSWC conveys storm water runoff from the surrounding mountains as well as developed areas
within the Coachella Valley. The elevation of the existing Dune Palms Road low-water crossing
causes it to flood during minor rain events (2-year frequency) and results in full street closure
and detour of both vehicle and pedestrian traffic. In the interest of public health and safety, and
in response to community concerns regarding frequent closures of the low-water crossing, the
City of La Quinta has determined that replacement of the low-water crossing with a new bridge
is needed to ensure that all-weather access is maintained. The Dune Palms Road low-water
crossing is the last remaining low-water crossing of the CVSWC within the City. The naturally-
occurring Whitewater River riverbed flows for approximately 25 miles before meeting the
CVSWC, which flows an additional 24.5 miles [CVWD].
ECORP Consulting, Inc. (ECORP) conducted a biological resource assessment and jurisdictional
wetland delineation of 0.25-miles along Dune Palms Road and adjacent impact areas in the
CVSWC. The jurisdictional delineation conformed to the unified federal method, as defined by
the U.S Army Corps of Engineers (USACE), using methodology outlined in the Corps of
Engineers Wetlands Delineation Manual [USACE 1987] and the Regional Supplement to the
Corps of Engineers Wetland Delineation Manual: Arid West Region (Arid West Region
Supplement Version 2.0) [USACE 2008]. This method consists of conducting field work using
paired sample point analysis, made in conjunction with aerial photograph interpretation, and
mapping of jurisdictional resources based on the location of Ordinary High Water Mark (OHWM)
for Waters of the US and limits of floodplain for Waters of the State, also known as California
Department of Fish and Wildlife (CDFW) Streambeds [USACE 2008].
DUNE PALMS ROAD LOW-WATER CROSSING REPLACEMENT PROJECT
ECORP Consulting, Inc. Dune Palms Road Low Water Crossing Replacement Project
ECORP Project No: 2014-173/004 Jurisdictional Delineation
September 2015 2
1.1 Project Location
The Project site is located in La Quinta, California, in a region known as Coachella Valley in
eastern Riverside County (Exhibit 1.1). The surrounding area is desert lowland that extends 45
miles southeastward from the San Gorgonio Pass region to the north end of the Salton Sea. The
Coachella Valley floor where the Project resides is bounded on the west by the Santa Rosa
Mountains and to the east by Mecca Hills. To the north of the Project, north of Interstate 10,
there is a mix of residential and undeveloped areas below the foothills of Joshua Tree National
Park (Exhibit 1.2). Dune Palms Road serves a vital access for emergency services within the
project area, as well as for La Quinta High, John Glen Middle and Amelia Earhart Elementary
Schools. It also provides connectivity of the city residential development north of the Channel
with the Highway 111 commercial corridor located south of the CVSWC.
The existing roadway crosses the CVSWC at the channel grade. The roadway width is 68 feet at
the crossing, and consists of one northbound and two southbound through lanes, eight foot
wide walkway area along the western edge, and an eight foot shoulder along the eastern edge
of the road, and no median. The existing roadway approach south of the crossing consists of
one northbound and two southbound through lanes. The northern roadway approach consists
of one through lanes in each direction. The transition from one to two lanes in the southbound
direction occurs at the midpoint of the channel crossing. Dune Palms Road approximately one-
quarter mile north of the channel low-water crossing and just south of the project limits is a
four lane roadway with a median. The roadway section just north of the crossing will be
widened as part of an approved City project. The project was originally approved with a
Mitigated Negative Declaration under California Environmental Quality Act (CEQA) in April 2010.
ECORP biologists characterized the biological resources in the Project area and immediate
vicinity by initially determining the limits of the Biological Study Area (BSA). The BSA is intended
to encompass the area within which all Project activities will occur, plus a buffer around the
Project site containing biological resources that may be indirectly impacted by Project activities.
ECORP determined that the BSA should include the entire “Temporary Construction Easement”
which includes all proposed work areas within the Project boundary and additional areas up and
downstream within the CVSWC.
1.2 Project Description
The project proposes to remove the existing low-water crossing of Dune Palms Road at the
CVSWC in the City of La Quinta, Riverside County. The crossing will be replaced with a 480 feet
long and 86 feet wide four-span bridge. The bridge typical section consists of six-foot sidewalk
on both sides of the bridge, two (2) eight-foot outside shoulders also serving as bike/golf cart
lanes, a 10 foot raised median, two (2) eleven-foot travel lanes, and two (2) twelve-foot travel
DUNE PALMS ROAD LOW-WATER CROSSING REPLACEMENT PROJECT
ECORP Consulting, Inc. Dune Palms Road Low Water Crossing Replacement Project
ECORP Project No: 2014-173/004 Jurisdictional Delineation
September 2015 3
lanes. The proposed configuration will be consistent with the existing four lane roadway section
to the south, and the City’s current improvement project to the north (project number 2009-
04), which will widen Dune Palms Road from two to four lanes with a median and left turn
lanes.
The proposed improvements will include a reconstruction of the north and south bridge
approaches to accommodate the significant raised profile of the roadway. In order to match the
roadway section on the south side of the bridge, the project’s construction limits will be
extended to 239 feet of Highway 111. On the north side of the bridge, the project construction
limits will be extended to include a vacant lot immediately north of the project limits. The
vacant lot is owned by the City and will be offered by the City in the bidding documents to be
used for storage and construction staging by the contractor for the construction of this project,
if needed.
As a part of the bridge construction, concrete slope protection will be installed along the north
side of the channel. Additionally, minor removal and replacement of slope protection will be
required on the south side of channel west of the proposed bridge and extension of slope
protection approximately 300 feet downstream of the proposed bridge. The slope protection is
needed for scour countermeasures. As a result of the proposed cast-in-place drilled shaft bridge
construction, scour protection within the bottom of the channel should not be required.
The project will also include the following additional improvements:
• Railing Architectural treatment. The bridge design will incorporate railing architectural
treatment as required by the City’s standard design.
• Integration of a regional Bike/Pedestrian/NEV corridor (CV Link). The Coachella Valley
Association of Governments (CVAG) and the communities within the Coachella Valley are
working together on the implementation of a regional Bike/Pedestrian/NEV corridor (CV
Link) along Whitewater River and Coachella Valley Storm Water Channel. The project
design will be consistent with these plans by allowing for the integration of a trail under
crossing within the southern slope protection, which also includes a trail connector to
the pedestrian and bike facilities proposed along Dune Palms Road in the project area.
• Utility Relocation. The project will also require utility relocations for overhead electrical
distribution lines (Imperial Irrigation District facility), adjustment to both water valve can
and lids and the manhole covers, minor 12” ductile iron pipe water main relocations at
each bridge abutment, and relocation of both a 12” and 18” sewer line at the northern
bridge abutment.
DUNE PALMS ROAD LOW-WATER CROSSING REPLACEMENT PROJECT
ECORP Consulting, Inc. Dune Palms Road Low Water Crossing Replacement Project
ECORP Project No: 2014-173/004 Jurisdictional Delineation
September 2015 4
The existing roadway will be modified to construct a temporary bypass road. The temporary
bypass will allow for staged construction of the bridge, and maintaining vehicle and pedestrian
access during the construction period. Temporary and short term access impact may occur
during construction, and will require coordination with property owners, the public, and other
stakeholders.
The Project will construct the bridge in a location that would roughly coincide with the existing
roadway footprint. This will minimize the permanent impacts to the CVSWC and the associated
environment.
The Project will require right-of-way acquisition on the northeast and southeast corners of the
proposed bridge. The existing development at the northeast corner of the proposed bridge
consists of a mobile home park with one single family home. Some of the mobile homes
adjacent to Dune Palms Road are encroaching within the street right-of-way. As a consequence,
the Project may require the acquisition of the single-family residence and relocation of two
mobile homes residents. The Project will be designed to avoid and minimize relocation impacts
of the mobile homes, to the extent possible.
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DUNE PALMS ROAD LOW-WATER CROSSING REPLACEMENT PROJECT
ECORP Consulting, Inc. Dune Palms Road Low Water Crossing Replacement Project
ECORP Project No: 2014-173/004 Jurisdictional Delineation
September 2015 7
2.0 REGIONAL SETTING
2.1 Existing Conditions
The City of La Quinta is 24.6 square miles, hosts a population of more than 45,000 full-time
residents, and lays at an average elevation of about 120 feet above sea level, with a climate
typified by about 6.3 inches of precipitation annually. Rainfall is fairly evenly distributed
throughout the year, the wettest month being January with an average of 1.1 inches of rainfall.
Temperatures in La Quinta usually range from the high 20s °F in the winter to an average 99 °F
in the summer. The climate in this part of Riverside County tends to be variable, temperatures
can fluctuate 28 degrees daily, and the warmest month is in August and the coolest month is in
January.
La Quinta is a city within of Riverside County, California, and is approximately 5.5 miles
southeast of Palm Springs and 15 miles northwest from Meca. La Quinta is located within
Coachella Valley, southeast of the San Gorgonio Mountains and east of the San Jacinto
Mountains, along Highway 111. The property is located within the City of La Quinta portion of
the Whitewater River Watershed, a watershed of approximately 32 square miles, which
ultimately leads to the Salton Sea Watershed.
The Project is surrounded by a residential community, highschool, Highway 111, and other
urban land uses. Vegetation within the site consists mostly of disturbed ruderal, urbanized,
ornamental, and non-native habitat. There are several mature ornamental trees and a sparsely-
vegetated corridor with some native shrubs along the existing concrete and rock lined bank
running through the CVSWC, consisting of a couple isolated patches of rubber rabbitbush, and
non-native vegetation. An open concrete storm water drainage pipe empties into the Project
area where some hydrophytic vegetation does occur. Most of the Project site is already
disturbed or developed, mostly being Dune Palms Road and the channelized CVSWC. The river
has intermittent to ephemeral flow, travelling southeast from the San Bernardino Mountains to
the Salton Sea.
The surrounding area is desert lowland that extends 45 miles southeastward from the San
Gorgonio Pass region to the north end of the Salton Sea. The Coachella Valley floor where the
Project resides is bounded on the west by the Santa Rosa Mountains and to the east by Mecca
Hills. To the north of the Project, north of Interstate-10, resides a mix of residential and
undeveloped areas below the foothills of Joshua Tree National Park.
Local topography consists of a relatively flat landscape within urbanized areas near the Project
area and a trapezoidal channel within the CVSWC. The Project site ranges in elevation from 40
to 80 feet above mean sea level (AMSL); 40 feet being in the middle of the CVSWC and 80 feet
DUNE PALMS ROAD LOW-WATER CROSSING REPLACEMENT PROJECT
ECORP Consulting, Inc. Dune Palms Road Low Water Crossing Replacement Project
ECORP Project No: 2014-173/004 Jurisdictional Delineation
September 2015 8
at the northern and southern-most parts of the Project site. Drainage tends to be directed north
and south into the CVSWC. Mount San Jacinto Peak, with an elevation of 10,834 feet, is
approximately 25 miles to the northwest of the Project site. US Forest Service lands begin about
eight miles to the west of the Project site.
2.2 Vegetation Communities
The BSA is comprised of predominantly disturbed riparian herbaceous areas associated with the
CVSWC. There is also a small amount of freshwater marsh associated with a pipe that releases
urban runoff into the channel. The upland areas comprise developed and disturbed areas.
There are no intact, natural vegetation communities in the BSA, though there are several areas
in that support scattered native shrubs, including rubber rabbitbush, creosote (Larrea
tridentata), and fourwing saltbush (Atriplex canescens). Following is a description of each
habitat type in the BSA.
Freshwater Marsh
Marsh habitats are wet areas associated with frequent inundation. Naturally these areas are
associated with either perennial streams or lakes or ponds. But in special circumstances where
water is frequently present, they can develop without those geographical features being
present. The marsh located within the Project area, along the western side of Dune Palms
Road, results from runoff from the high school into the CVSWC that empties into a short gully
before seeping into the sandy areas of the larger channel. Vegetation within this marsh area
includes narrow-leaved cattail (Typha latifolia), rabbit-foot grass (Polypogon monspeliensis),
and cocklebur (Xanthium strumarium). The marsh is approximately 0.03 acre in extent within
the BSA.
Disturbed Riparian Herbaceous
Disturbed Riparian Herbaceous habitat is characterized by non-native, often annual plants
associated with the CVSWC. Many of the plant species within the channel are considered
“ruderal” plants, associated with human settlements and urban areas, such as vacant lots, but
also along edges of agricultural fields and other human-modified environments. Dominant
species in this community on site include castor bean (Ricinis communis), Russian thistle
(Salsola tragus), cheeseweed (Malva parviflora), common sow-thistle (Sonchus oleraceus) and
non-native annual grasses such as wild oat (Avena sp.) and rip-gut brome (Bromus diandrus).
The habitat is approximately 5.77 acres in extent within the BSA.
DUNE PALMS ROAD LOW-WATER CROSSING REPLACEMENT PROJECT
ECORP Consulting, Inc. Dune Palms Road Low Water Crossing Replacement Project
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September 2015 9
Disturbed/Developed Areas
Disturbed/Developed is not a vegetation classification, but rather a land cover type that is either
largely devoid of vegetation due to human development, or dominated by unnatural vegetation
such as lawns and landscaping. Often areas surrounding this land cover type support non-
native, invasive plant species. Disturbed/Developed cover type occurs in the northern portion of
the BSA, as well as along the Dune Palms Road alignment (Figure 7). Portion of the BSA,
predominantly within and bordering developed areas, are planted in ornamental vegetation.
Numerous non-native plants used in landscaping these areas within the BSA include eucalyptus
trees (Eucalyptus sp.), Peruvian pepper tree (Schinus molle), Mexican fan palm (Washingtonia
robusta), oleander shrubs (Nerium oleander), and hottentot fig (Carpobrotus edulis). Disturbed
habitats within the vacant parcel on adjacent uplands is dominated by lamb’s quarters
(Chenopodium album), black mustard (Brassica nigra), Bermuda grass (Cynodon dactylon), and
purple fountain grass (Pennisetum setaceum). Scattered throughout the disturbed habitat are a
few native perennial shrubs, including creosote (Larrea tridentata) and fourwing saltbush
(Atriplex canescens); however the disturbed nature of the soils and vegetation where these
shrubs occur, as well as the paucity of native perennial shrubs, precludes these areas from
being characterized as desert scrub habitat. Within the BSA, approximately 1.97 acres is
considered disturbed and 3.15 acres are considered developed.
2.3 Soils
The soils within the BSA have been highly modified from their natural condition through
anthropogenic disturbances associated with urbanization, road construction, and channelization
of the Whitewater River into the CVSWC. Two soil types have been mapped in the BSA by the
National Resources Conservation Service (NRCS) Web Soil Survey, including Coachella fine sand
in the CVSWC and Myoma fine sand in the adjacent uplands (Exhibit 2.1). The Coachella series
soils are characterized as well-drained, moderately to rapidly permeable soils. They are alluvial
soils formed predominantly from igneous rocks and are found in water channels and basins.
The Myoma series soils are eolian sediments that originated from recent alluvium, and are
characterized by moderately alkaline, fine and very fine sands. In their natural state they are
nearly level to rolling, with hummocky micro-relief.
Hydric soil types are those which, according to the NRCS, are affiliated with hydrogeomorphic
features, such as streams, or that may support wetlands. Typically hydric soils are those that
are sufficiently wet in the upper part to develop anaerobic conditions during the growing
season. The Coachella series CpA soil type on the Project site is well-drained, moderately rapid
permeable soils in lacustrine basins and is potentially hydric. The CpA is located within the
CVSWC, a channelized drainage that directs flow from the San Bernardino Mountains into the
Salton Sea. Although hydric conditions may be present in this soil, perched water tables are
DUNE PALMS ROAD LOW-WATER CROSSING REPLACEMENT PROJECT
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ECORP Project No: 2014-173/004 Jurisdictional Delineation
September 2015 10
infrequent within the drainage and anaerobic conditions are unlikely. The CpA is most likely not
a hydric soil.
2.4 Watersheds
The Project site is located within the Whitewater River Watershed (Watershed) (Hydrologic Unit
Code [HUC] 18070203) (Exhibit 2.2). The Whitewater River, also called the CVSWC, is the
primary drainage and channel for the Watershed, which flows through most of Coachella Valley
into the Salton Sea. The Watershed is approximately 350 square miles and all drainage features
within the Project site drain to the CVSWC. The Watershed is generally defined by the
boundaries of the Whitewater Hydrologic Unit as described in the Water Quality Control Plan for
the Colorado River Basin Regional Water Quality Control Board. Much of the Watershed consists
of sparsely populated mountains, desert, and agricultural lands. Urbanized areas are principally
located on the valley floor between Banning and Indio along Interstate 10, and from Palm
Springs to Coachella along State Highway 111.
The Whitewater River Watershed encompasses approximately 350 square miles (224,000
acres), spanning parts of San Bernardino and Riverside counties, following the path of the
Whitewater River, whose headwaters are located in the San Bernardino Mountains near San
Gorgonio Summit within National Forest lands to the east of the City of San Bernardino. The
San Bernardino Mountains comprise part of the Transverse Ranges of California and trend
northwest to southeast. The Whitewater River flows for approximately 49.5 miles through a
combination of natural areas and urban environments to enter the Salton Sea near Mecca,
California [CVWD].
There is little to no perennial surface water in most of the Watershed’s various drainage
courses. A majority of the water is immediately drained into the Colorado River Aqueduct
located towards the beginning headwaters of the Watershed. Afterwards, surface flow is
naturally drained into underground basins or to a series of groundwater recharge basins that
are located northeast of the urbanized Watershed area and managed by the CVWD. This
section of the CVSWC rarely flows past the recharge basins, and does not contribute
significantly to downstream water quality or quantity. Only during major extended rainfall
events does the northern reach of the CVSWC flow beyond the CVWD recharge basins. The
portion of the Whitewater River within the Project BSA is located upstream of the basin, and
water quality pollutants from this area will eventually drain into this basin.
MaD
MaD
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CpA
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Map Date: 1/7/2015Photo Source: NAIP (2012)Exhibit 2.1
NRCS Soils
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Scale in Feet
Map Features
Project Boundary
NRCS Soil Types
CpA - Coachella fine sand, 0 to 2 percent slopes
MaB - Myoma fine sand, 0 to 5 percent slopes
MaD - Myoma fine sand, 5 to 15 percent slopes
Natural Resources Conservation Service (NRCS)Soil Survey Geographic (SSURGO) Database for Riverside County, CA
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Bear Creek181002010701
LowerDeep Canyon181002010503
City ofIndio-Whitewater River181002010705
Town of BiskraPalms-Whitewater River181002010609
Town ofThermal-Whitewater River181002010802
City of IndianWells-Whitewater River181002010608
Exhibit 2.2. HUC 12 Watershed
2014-173 La Quinta Dune Palms
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3.0 METHODS
This wetland delineation was conducted in accordance with the Corps of Engineers Wetlands
Delineation Manual [USACE 1987] and the Interim Regional Supplement to the Corps of
Engineers Wetland Delineation Manual: Arid West Region (Arid West Region Supplement
Version 2.0) [USACE 2008]. The boundaries of potential waters of the U.S. were delineated
through field assessment, made in conjunction with research of hydrological connectivity, soils
data, aerial photograph interpretation, and sample point analyses. All wetland data were
recorded on Arid West Region - Wetland Determination Data Forms (Appendix B). A color aerial
photograph was used to assist with mapping and ground-truthing. Munsell Soil Color Charts
[GretagMacbeth] was used to aid in identifying hydric soils in the field. The Jepson Manual
[Hickman, ed.] was used for plant nomenclature and identification. Vegetation community
designations follow A Manual of California Vegetation [Sawyer et al.].
3.1 U.S. ARMY CORPS OF ENGINEERS (USACE) JURISDICTION
This report describes potential waters of the U.S. that may be regulated by the USACE under
Section 404 of the Clean Water Act. Wetlands are “those areas that are inundated or saturated
by surface or groundwater at a frequency and duration sufficient to support, and that under
normal circumstances do support, a prevalence of vegetation typically adapted for life in
saturated soil conditions” [USACE 1986b]. Wetlands can be perennial or intermittent, and
isolated or adjacent to other waters.
Other waters are non-tidal, perennial, and intermittent watercourses and tributaries to such
watercourses [USACE 1986 a]. The limit of USACE jurisdiction for non-tidal watercourses (without
adjacent wetlands) is defined in 33 CFR 328.4(c)(1) as the “ordinary high water mark” (OHWM).
The OHWM is defined as the “line on the shore established by the fluctuations of water and
indicated by physical characteristics such as clear, natural line impressed on the bank, shelving,
changes in the character of soil, destruction of terrestrial vegetation, the presence of litter and
debris, or other appropriate means that consider the characteristics of the surrounding areas”
[USACE 1986 e]. The bank-to-bank extent of the channel that contains the water-flow during a
normal rainfall year generally serves as a good first approximation of the lateral limit of USACE
jurisdiction. The upstream limits of other waters are defined as the point where the OHWM is
no longer perceptible.
To be determined a wetland; the following three criteria should be met:
• A majority (greater than 50 percent) of dominant vegetation species are wetland
associated species;
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• hydrologic conditions exist that result in periods of flooding, ponding, or saturation for at
least 5 percent of the growing season; and,
• soils must exhibit hydric characteristics indicative of permanent or periodic inundation.
The aforementioned characteristics may not apply to isolated, non-navigable waters (such as
vernal pools) pursuant to the January 9, 2001 Supreme Court decision in the case of Solid
Waste Agency of Northern Cook County versus U.S. Army Corps of Engineers (SWANCC)
[SWANCC]. The SWANCC decision eliminated jurisdiction over isolated, intrastate, non-
navigable waters where the sole basis of jurisdiction is founded on the presence of migratory
bird habitat.
A memorandum, dated June 5 2007, was issued by the USACE to address a pair of court cases:
Rapanos versus United States [Rapanos] and Carabell versus United States [Carabell]. This
memorandum asserts USACE and Environmental Protection Agency jurisdiction over Traditional
Navigable Waters (TNW) and all wetlands adjacent to TNWs, but also asserts jurisdiction over
certain non-navigable waterways if the waterway is a Relatively Permanent Waterway (RPW).
An RPW must either flow year-round or seasonally. The other standard introduced by the
Rapanos guidance is the existence of a “significant nexus” in determining whether waters (and
adjacent wetlands) are jurisdictional by drawing a connection between the waterway and a
TNW or RPW. Determination of a “significant nexus” involves a functional analysis, and
consideration of both hydrological and ecological factors for each tributary.
Vegetation
Hydrophytic vegetation is defined as the sum total of macrophytic plant life that occurs in areas
where the frequency and duration of inundation or soil saturation produce permanent or
periodically saturated soils of sufficient duration to exert a controlling influence on the plant
species present [GretagMacbeth]. The definition of wetlands includes the phrase "a prevalence
of vegetation typically adapted for life in saturated soil conditions." Prevalent vegetation is
characterized by the dominant plant species comprising the plant community [GretagMacbeth].
The "50/20 rule" was used to determine the dominant plant species at each data point location.
The rule states that for each stratum in the plant community, dominant species are the most
abundant plant species (when ranked in descending order of abundance and cumulatively
totaled) that immediately exceed 50 percent of the total dominance measure for the stratum,
plus any additional species that individually comprise 20 percent or more of the total dominance
measure for the stratum [HQUSACE].
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Dominant plant species observed at each data point were then classified according to their
indicator status (probability of occurrence in wetlands) (Table 1), in accordance with the U.S.
Fish and Wildlife Service's National List of Vascular Plant Species That Occur in Wetlands:
California (Region 0) [USFWS]. If the majority (greater than 50 percent) of the dominant
vegetation on a site are classified as obligate (OBL), facultative wetland (FACW), or facultative
(FAC) (excluding FAC-), then the site is considered to be dominated by hydrophytic vegetation.
Table 1 - Classification of Wetland-Associated Plant Species1
Plant Species Classification Abbreviation2 Probability of Occurring in Wetland
Obligate OBL >99%
Facultative Wetland FACW 66-99%
Facultative FAC 33-66%
Facultative Upland FACU 1-33%
Upland UPL <1%
No indicator status NI Insufficient information to determine
status
Plants That Are Not Listed
(assumed upland species)
NL Does not occur in wetlands in any region.
1 Source: Reed 1988
2 A ‘+’ or ‘–’ symbol can be added to the classification to indicate greater or lesser probability,
respectively, of occurrence in a wetland.
The Dominance Test was supplemented by the Prevalence Index (PI), where applicable. The PI
is applied where vegetation fails the Dominance Test but both soil and hydric indicators are
positive. The Index is a weighted-average wetland indicator status of all species within a plot by
indicator status category. The formula utilized in this calculation is as follows:
PI = AOBL + 2AFACW + 3AFAC + 4AFACU + 5AUPL
AOBL + AFACW + AFAC + AFACU + AUPL
Where:
PI = Prevalence Index
AOBL = Summed percent cover values of obligate (OBL) plant species
AFACW = Summed percent cover values of facultative wetland (FACW) plant species
AFAC = Summed percent cover values of facultative (FAC) plant species
AFACU = Summed percent cover values of facultative upland (FACU) plant species
AUPL = Summed percent cover values of upland (UPL) plant species
The PI needs to be less than or equal to 3.0 to be considered indicative of the presence of
hydrophytic vegetation. As a third step in evaluating the vegetation, an assessment of any
observed Morphological Adaptations to upland plants was made. If upland plants show
adaptations to wet conditions (for example, adventitious roots), they may be reclassified as a
FAC species and the PI may be recalculated.
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Soils
A hydric soil is defined as a soil that formed under conditions of saturation, flooding, or ponding
long enough during the growing season to develop anaerobic conditions in the upper part
[USDA]. Indicators that a hydric soil is present could include soil color (gleyed soils and soils
with bright mottles and/or low matrix chroma), aquic or preaquic moisture regime, reducing soil
conditions, sulfidic material (odor), soils listed on hydric soils list, iron and manganese
concretions, organic soils (Histosols), histic epipedon, high organic content in surface layer in
sandy soils, and organic streaking in sandy soils. Applicability of specific soil indicators for hydric
soils on the project site were determined by using the Regional Supplement to the Corps of
Engineers Wetland Delineation Manual: Arid West Region [USACE 2008].
No soil pit was excavated to a depth of 16 inches or refusal at each data point because the
wetland point was located within a concrete channel and the upland point was located on
private property. This would typically be done to a depth of 16 inches or refusal at each data
point to document an indicator, or to confirm the absence of indicators. The soil would then be
examined for hydric soil indicators and the matrix color and mottle color (if present) of the soil
would be determined using the Munsell Soil Color Charts [GretagMacbeth].
Hydrology
Wetlands, by definition, are seasonally or perennially inundated or saturated at or near (within 12
inches of) the soil surface. Primary indicators of wetland hydrology include, but are not limited
to: visual observation of saturated soils, visual observation of inundation, surface soil cracks,
inundation visible on aerial imagery, water-stained leaves, oxidized rhizospheres along living
roots, aquatic invertebrates, water marks (secondary indicator in riverine environments), drift
lines (secondary indicator in riverine environments), and sediment deposits (secondary indicator
in riverine environments). The occurrence of one primary indicator is sufficient to conclude that
wetland hydrology is present. If no primary indicators are observed, two or more secondary
indicators are required to conclude wetland hydrology is present. Secondary indicators include,
but are not limited to: drainage patterns, crayfish burrows, FAC-neutral test, and shallow
aquitard. The occurrence of at least one primary indicator or two secondary indicators is
required to confirm the presence of wetland hydrology.
3.2 California Department of Fish and Wildlife (CDFW) Jurisdiction
The CDFW regulates projects that propose to (1) divert, obstruct, or change the natural flow or
the bed, channel, or bank of any river, stream, or lake designated by the department in which
there is at any time an existing fish or wildlife resource or from which these resources derive
benefit, (2) use material from the streambeds designated by the department, or (3) result in
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the disposal or deposition of debris, waste, or other material containing crumbled, flaked, or
ground pavement where it can pass into any river, stream, or lake designated by the
department. If an existing fish or wildlife resource may be substantially adversely affected by
that construction, the department shall notify the governmental agency or public utility of the
existence of the fish or wildlife resource together with a description thereof and shall propose
reasonable modifications in the proposed construction that will allow for the protection and
continuance of the fish or wildlife resource, including procedures to review the operation of
those protective measures. CDFW jurisdiction includes the definable bed, bank, or channel,
areas that support periodic or intermittent flows, perennial flows, subsurface flows, support fish
or other aquatic life and areas that support riparian or hydrophytic vegetation in association
with a streambed. Projects that affect the CDFW jurisdictional areas must apply for a
Streambed Alteration Agreement.
3.3 Regional Water Quality Control Board (RWQCB) Jurisdiction
The RWQCB regulates wastewater discharges into all surface waters and to groundwater. The
RWQCB also regulates storm water discharges from construction, industrial, and municipal
activities; discharges from irrigated agriculture; dredge and fill activities; the alteration of any
federal water body under the federal Clean Water Act Section 401 certification program; and
several other activities that could degrade water quality. In most cases, a permit from the local
RWQCB is required for proposed discharges or activities from a project that could affect
California's surface, coastal, or ground waters. Regulated waters are broad in definition and
scope. Regulated waterbodies include any “surface water or groundwater, including saline
waters, within the boundaries of the state.” The regulations encompass all waters of the U.S.,
including wetlands, as well as all waters of the state. RWQCB publishes no methodology for
determining their jurisdictional boundaries, but rather coordinates with other regulatory
agencies and determines their jurisdictional boundaries based on these agency’s findings.
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4.0 RESULTS
ECORP biologists Kevin Cornell and Scott Taylor conducted a jurisdictional delineation, on
February 13, 2015, to map the limits of streambeds and other jurisdictional resources.
Within the BSA, the CVSWC was determined to be a potential jurisdictional Waters of the U.S.
as set forth in 33 CFR 328.33(a). There was also a potential jurisdictional wetland area found to
the west of Dune Palms Road, associated with a pipe outlet conveying urban runoff. The
jurisdictional portion of the channel accounts for a total of 2.20 acres and 490 linear feet of
intermittent streambed and 0.28 acre and 15 linear feet of wetland within the BSA (Table 2;
Exhibit 4.1). The water of the U.S. that was delineated on the property is considered to be an
intermittent stream. The wetland found consisted of a freshwater marsh. A discussion of the
features present within the property is presented below. The Arid Wetland Determination Data
Forms are included in Appendix B.
Table 2. Potential Waters of the U.S.
Waters by Drainage Acres Square Feet Linear Feet
Coachella Valley Storm Water Channel –
Intermittent Stream
2.20 95,832 490
Freshwater Marsh - Wetland 0.28 12,197 15
Total 2.48 108,029 505
4.1 Potential Waters of the U.S.
Wetlands
One feature within the Project area was a freshwater marsh that met the necessary criteria to
meet the federal definition of wetlands. The feature was located within a short drainage gully
associated with a pipe outlet that conveyed urban runoff. A pair of sample points was taken
along the western boundary of the Project site in a concrete drainage within the CVSWC and
upland above the concrete drainage. This area was chosen because it was the only surface with
both water present and hydrophytic vegetation.
According to the vegetation test, hydrophytic vegetation was present. Hydrophytic specie
observed included narrow-leave cattails (a wetland obligate) and cocklebur (a facultative
wetland species). Soils consisted of silty clay and loamy sand, with one indicator of hydric soils
– sandy mucky material. There were also hydrology indicators present in the wetland – surface
soil cracks, water-stained leaves, and an obvious biotic crust. Although the feature developed as
a result of human influence and urban runoff, the feature is considered to be a wetland due to
the presence of the three wetland criteria. No other wetland indicator points were taken on the
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property and no areas are considered to meet the criteria to be considered a jurisdictional
wetland.
4.2 Other Waters of the U.S.
The other waters of the U.S. that occur within the project area consist of an intermittent stream
area (CVSWC) with an OHWM that had evidence of regular hydrology.
Intermittent Stream
A stream is considered to be an intermittent stream when it flows seasonally; more than just
immediately following precipitation events. Seasonal is usually considered a three-month
timeframe. Intermittent streams are generally dry for most of the year. Flow indicators and the
extent of jurisdiction within an intermittent stream reflect the degree of runoff during an
average year. The OHWM boundaries of the intermittent streams are formed by the regular
scouring of storm flows. An intermittent stream is generally considered to be an RPW.
The functions that intermittent streams provide are variable, including wildlife habitat,
groundwater recharge, floodwater storage, and sediment transport. During exceptionally dry
years, these streams can be dry all year. Intermittent streams are located above the water table
year-round, meaning that groundwater is not a significant source of water.
The intermittent stream on the Project site is channelized with areas of concrete banks adjacent
to Dune Palms Road within the CVSWC. The CVSWC is located on both sides of Dune Palms
Road and flows across the Project site. Flow direction is west to east within the Project site. The
majority of the channel is vegetated with non-native plants, including castor bean and Russian
thistle. The entire channel is clearly defined because it is all constructed of concrete. Evidence
of water flows was present in all portions of the drainage through small amounts of wear in the
concrete. Some surface water was present in areas of the jurisdictional drainages.
CVSWC
CVSWC is a heavily altered channel that is trapezoidal in cross section with concrete sides and
an earthen bottom for a majority of the channel in urbanized areas. It follows the historic path
of the Whitewater River. The Whitewater River is a 45 mile stream that originates in the San
Bernardino Mountains and terminates near the Salton Sea. The majority of its length is
channelized. Photos of CVSWC are located within Appendix D.
CVSWC is considered an intermittent stream because portions of it have been observed to
sustain seasonal flows. Most of these flows are due to regular urban runoff from residential
areas and golf courses along its path, but occasionally storm events will result in runoff
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sufficient to inundate the channel or portions of it. At the time of the survey work, pooling
water was observed within the channel.
The northern and southern limits of the waters of the U.S. for CVSWC coincided with the
location of the OHWM (i.e., outer sandy bank) for the main channel bed. The limit also
coincided with vegetative differences. The area delineated as waters of the U.S. exhibit greater
vegetative density than the area outside of these limits. The eastern and western limits of
mapped waters of the U.S. was delineated by the BSA boundary.
Vegetation within the CVSWC consists mainly of disturbed riparian herbaceous plant species,
which accounts for up to 40 percent of the estimated cover. The remainder of the cover
consisted of sandy bare ground. Evidence of recent disturbances by tracked vehicles within the
wash was also present. None of the plant species are considered to be obligate wetland plant
species, although the castor bean and other herbaceous plants are considered to be
hydrophytic.
The soil present within the channel consisted of alluvial sand. The soils were light in color
indicating that they contain little to no organic materials.
4.3 CDFW Jurisdiction
CDFW jurisdiction includes the entirety of the USACE jurisdictional features cited above. Prior to
project implementation, a 1602 Streambed Alteration Agreement from the CDFW would be
required for impacts to jurisdictional areas.
4.4 RWQCB Jurisdiction
Based on the results of this study presented in Section 4, potential RWQCB jurisdiction was
determined to include the entire impacted Waters of the State located within the Project area.
Prior to issuing a 404 permit for the project, a 401 water quality certification would be required
for impacts to the jurisdictional areas. Based on preliminary engineering for the Project, there
would be 0.05 acre and 12 linear feet of temporary impacts and 0.02 acre and five linear feet of
permanent impacts to RWQCB jurisdictional areas.
Map Date: 3/25/2015Photo Source: Esri Exhibit 4.1Jurisdictional Delineation
2014-173 La Quinta Dune PalmsLocation: N:\2014\2014-173 La Quinta Dune Palms\MAPS\Wetland_Mapping\Wetland_Delineation\v1\LQDP_JD_V1.mxd (MAG)-mguidry 3/25/2015 !>!>
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!>Sample Point
Existing Low Flow Crossing
Waters of the US / State
Intermittent Stream / Streambed(2.20 ac - 490 linear feet)
Wetland / Freshwater Marsh(0.28 acres - 15 linear feet)
I
0 200
Scale in Feet
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4.4 Project Impacts
In total, USACE jurisdiction features being impacted consist entirely of intermittent stream
within a previously disturbed drainage channel. The construction of this feature was considered
an authorized impact because it was constructed prior to the Clean Water Act. Typically all
impacts to previously authorized constructed features are considered to be temporary impacts.
Based on preliminary engineering for the Project, there would be 0.05 acre and 12 linear feet of
temporary impacts and 0.02 acre and five linear feet of permanent impacts to USACE
jurisdictional areas. The impacts below are depicted showing both temporary and permanent
impacts for each project alternative (Table 3) and depicted on Exhibits 4.2 and 4.3 below.
Table 3: Potential USACE Jurisdictional Area Impacts
Geomorphic Feature
Impacts (Acres/Linear
Feet)
Temporary Permanent
Intermittent Stream
(CVSWC) 0.05/12 0.02/5
Wetland 0/0 0/0
Total 0.05/12 0.02/5
Based on preliminary engineering for the Project, there would be 0.05 acre and 12 linear feet of
temporary impacts and 0.02 acre and five linear feet of permanent impacts to CDFW and
RWQCB jurisdictional areas.
Before construction activities begin for the proposed project, the following approvals/ permits
must be obtained or determined not applicable by the Department through additional
coordination with the applicable Federal and State resource agencies:
• Streambed Alteration Agreement pursuant to California Fish and Game Code Section 1602;
• USACE Nationwide Permit pursuant to CWA Section 404; and RWQCB 401 Water Quality
Certification pursuant to CWA Section 401.
Exhibit 4.2 Ju risdictio nal Delin eat ion Temp orary Impacts
Map Date : 4/24/2015Photo Sourc e: Es ri
2014-17 3 La Quin ta D une Pa lm sLocation: \\rocklin\mapping data\2014\2014-173 La Quinta Dune Palms\MAPS\Wetland_Mapping\Wetland_Delineation\v1\LQDP_JD_V1_TempImpacts.mxd (MAG)-mguidry 4/24/2015 !>!>
Coachella Valley Storm ChannelDune Palms RdDune Palms RdCorporate Centre Dr
Corporate Centre Dr
sp1
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Tem por ar y Const r uct ion Ease me nt
Tem por ar y Im pa ct s
!>Sam ple P oint
Existing Lo w F lo w Cro ssing
Wate rs of th e US / St at e
In te rm itte nt St r eam / S tr eam b ed(2.20 a c - 49 0 lin ear fe et )
Wetland / Fr esh wat er M a rs h(0.28 a cr es - 1 5 lin ear fe et )
I
0 200
S c a l e i n F e e t
Exhibit 4.3 Ju risdictio nal Delin eat ion Permanen t Impacts
Map Date : 4/24/2015Photo Sourc e: Es ri
2014-17 3 La Quin ta D une Pa lm sLocation: \\rocklin\mapping data\2014\2014-173 La Quinta Dune Palms\MAPS\Wetland_Mapping\Wetland_Delineation\v1\LQDP_JD_V1_PermImpacts.mxd (MAG)-mguidry 4/24/2015 !>!>
Coachella Valley Storm ChannelDune Palms RdDune Palms RdCorporate Centre Dr
Corporate Centre Dr
sp1
sp1a
Tem por ar y Const r uct ion Ease me nt
Perm an ent I m pac ts
!>Sam ple P oint
Existing Lo w F lo w Cro ssing
Wate rs of th e US / St at e
In te rm itte nt St r eam / S tr eam b ed(2.20 a c - 49 0 lin ear fe et )
Wetland / Fr esh wat er M a rs h(0.28 a cr es - 1 5 lin ear fe et )
I
0 200
S c a l e i n F e e t
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5.0 CONCLUSIONS AND RECOMMENDATIONS
5.1 Conclusions
The final determination of the limits of the jurisdictional areas within the BSA and whether
mitigation will be required for such impacts is ultimately subject to the discretion of the
agencies (i.e., CDFW, USACE, and RWQCB) during the federal and state regulatory permitting
processes. Based on preliminary engineering for the Project, there would be 0.05 acre and 12
linear feet of temporary impacts and 0.02 acre and five linear feet of permanent impacts to
USACE, CDFW, and RWQCB jurisdictional areas. As previously discussed in Sections 4.1.1 and
4.1.2, impacts to jurisdictional areas would occur during construction of the proposed Project.
Before construction for the proposed project begins, the following permits must be obtained or
determined not applicable through additional coordination with the applicable federal and state
resource agencies: Section 404 authorization from USACE (Linear Transportation Projects),
Section 401 Water Quality Certification from RWQCB, and Section 1602 Streambed Alteration
Agreement from CDFW. Measures to address unavoidable impacts will be negotiated with
resource agencies and incorporated into the environmental commitments record for the project
before construction begins.
The placement of fill materials within jurisdictional features would require permitting pursuant
to Section 404 and 401 of the federal Clean Water Act. The CDFW jurisdiction completely
overlaps the USACE jurisdiction. Areas considered jurisdictional waters of the U.S. are subject to
permitting and authorization through the USACE, which authorizes impacts under Section 404 of
the federal Clean Water Act and the State Water Quality Control Board, where such impact can
have an effect on water quality. The CDFW authorizes impacts to waters of the state, including
lakes and streambeds, under state codes (Section 1600).
If the areas on the property that are potentially jurisdictional are determined by the agencies to
be jurisdictional, then subsequent permitting and authorization would be required prior to
disturbance of those features. Impacts to jurisdictional features are anticipated during the
construction phase of the proposed project.
5.2 Avoidance and Minimization Recommendations
Waters of the U.S. impacts have been avoided to the maximum extent practicable by project
design to avoid work that fills these areas. Temporary impacts are necessary to divert traffic
away from the location of the permanent bridge during the construction period. The temporary
impact areas would be restored to existing topography after construction has been completed.
The location of the permanent bridge structure would coincide with the existing location of the
low-flow crossing within Dune Palms Road.
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The following measures are proposed to reduce and minimize impacts:
• Project construction activities are anticipated to occur through the rainy season. Should
surface water flow occur through the project area at any point, then the contractor will
initiate appropriate BMPs. Groundwater levels are below the level of anticipated Project
excavations.Construction activities within the CVSWC will be designed/conducted to
maintain downstream flow conditions.
• ESAs will be incorporated into the plans and specifications for the project so that the contractor
is aware of the limits of allowable site access and disturbance.
• BMPs will be implemented to preserve downstream water quality.
• All drainages temporarily impacted during construction will be returned to their original
contours at the end of project activities.
• Measures will be adopted to prevent potential pollutants from entering the watercourse.
Construction materials and debris will not be stored in drainages to prevent spills/runoff
from entering jurisdictional areas.
Specific mitigation for the temporary impacts to waters of the U.S. is not being proposed due to
the disturbed nature of the habitats to be impacted. Additional mitigation, if required, will be
conducted in the context of the regulatory permitting process for the Project. No mitigation of
temporary impacts to unvegetated channels within the study corridor is being proposed other
than re-contouring of the area being impacted to match pre-project conditions. For permanent
impacts, no mitigation is proposed because the Project impacts are to highly disturbed areas
and the Project would remove the concrete low-flow crossing that is currently in place and re-
contour that area to a natural condition. The Project would have a net beneficial impact due to
a net reduction in the impact footprint of the road crossing.
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6.0 CERTIFICATION
I hereby certify that the statements furnished above and in the attached exhibits present the
data and information required for this biological evaluation, and that the facts, statements, and
information presented are true and correct to the best of my knowledge and belief. Field work
conducted for this assessment was performed by me or under my direct supervision. I certify
that I have not signed a non-disclosure or consultant confidentiality agreement with the project
applicant or the applicant’s representative and that I have no financial interest in the project.
DATE: SIGNED: _________________________
Mr. Scott Taylor
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7.0 REFERENCES
Baldwin, B.G; D.H. Goldman; D.J. Keil; R. Patterson; and T.J. Rosatti, editors. 2012.
The Jepson Manual: Vascular Plants of California, Second Edition. University
of California Press, Berkeley.
California Environmental Protection Agency (CEPA). 2011. Salton Sea Transboundary
Watershed. State of California, State Water Resources Control Board.
Accessed online at on January 3, 2012.
City of Coachella. 2015. General Plan Update Final EIR; Section 4.7, Water Quality
and Hydrology.
Coachella Valley Water District (CVWD). 2015. Coachella Valley: An H2Oasis.
http://www.cvwd.org/about/waterandcv.php on February 27, 2015.
Holland, R.F. 1986. Preliminary Descriptions of the Terrestrial Natural Communities of
California. Non-game Heritage Program. California Department of Fish and
Game. Sacramento, CA. Updated in 1992.
Kollmorgen Instruments Company. 1990. Munsell Soil Color Charts. Kollmorgen
Corporation. Baltimore, Maryland.
Lichvar, R.W. and S.M. McColley. 2008. A Field Guide to the Identification of the
Ordinary High Water Mark (OHWM) in the Arid West Region of the Western
United States. U.S. Army Corps of Engineers, Cold Regions Research and
Engineering Laboratory.
Lichvar, R.W., N.C. Melvin, M. Butterwick, and W.N. Kirchner. 2012. National Wetland
Plant List Indicator Rating Definitions. U.S. Army Corps of Engineers, Engineer
Research and Development Center.
Lichvar, R.W., M. Butterwick, N.C. Melvin, and W.N. Kirchner. 2014. The National
Wetland Plant List: 2014 Update of Wetland Ratings. Phytoneuron 2014-41:
1-42. Retrieved from U.S. Army Corps of Engineers, Engineer Research and
Development Center website: http://wetland_plants.usace.army.mil/.
Sawyer, J. O., T. Keeler-Wolf, and J. M. Evens. 2009. A manual of California
vegetation, 2nd ed. California Native Plant Society, Sacramento, CA.
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U.S. Army Corps of Engineers (USACE). 1987. Corps of Engineers Wetlands
Delineation Manual. Technical Report Y-87-1. U. S. Army Engineer
Waterways Experiment Station. Vicksburg, Mississippi.
U. S. Army Corps of Engineers (USACE). 2008. Regional Supplement to the Corps of
Engineers Wetland Delineation Manual: Arid West Region (Version 2.0). ed.
J.S. Wakeley, R.W. Lichvar, and C.V.
U.S. Department of the Interior, Fish and Wildlife Service (USFWS). 2014. National
Wetlands Inventory. Available Online:
http://www.fws.gov/wetlands/Data/Mapper.html
U.S. Department of the Interior, Geological Survey (USGS). 1984. “Cathedral City,
California” 7.5-minute Quadrangle. Geological Survey. Denver, Colorado.
U.S. Department of the Interior, Geological Survey (USGS). 1984. “Myoma,
California” 7.5-minute Quadrangle. Geological Survey. Denver, Colorado.
U.S. Department of the Interior, Geological Survey (USGS). 1984. “West Berdoo
Canyon, California” 7.5-minute Quadrangle. Geological Survey. Denver,
Colorado.
U.S. Department of the Interior, Geological Survey (USGS). 1984. “Indio, California”
7.5-minute Quadrangle. Geological Survey. Denver, Colorado.
U.S. Department of the Interior, Geological Survey (USGS). 1984. “Valerie, California”
7.5-minute Quadrangle. Geological Survey. Denver, Colorado.
U.S. Department of the Interior, Geological Survey (USGS). 1984. “Martinez
Mountain, California” 7.5-minute Quadrangle. Geological Survey. Denver,
Colorado.
U.S. Department of the Interior, Geological Survey (USGS). 1984. “Toro Peak
Mountain, California” 7.5-minute Quadrangle. Geological Survey. Denver,
Colorado.
U.S. Department of the Interior, Geological Survey (USGS). 1984. “Rancho Mirage
Mountain, California” 7.5-minute Quadrangle. Geological Survey. Denver,
Colorado.
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U.S. Environmental Protection Agency and U.S. Army Corps of Engineers (USEPA and
USACE). 2007. Memorandum Re: Clean Water Act Jurisdiction Following the
U.S. Supreme Court's Decision in Rapanos v. United States & Carabell v.
United States. Dated 5 June 2007.
U.S. Department of Agriculture (USDA). 2014. Web Soil Survey: Riverside County,
California. Department of the Interior.
Appendix A
Botanical Compendium
Scientific Name Common Name
APOCYNACEAE DOGBANE FAMILY
Nerium oleander*Oleander
ASTERACEAE SUNFLOWER FAMILY
Ambrosia acanthicarpa Annual bur-sage
Ambrosia psilostachya Western ragweed
Helianthus annuus common sunflower
Palafoxia arida Spanish needles
Xanthium strumarium cocklebur
BORAGINACEAE BORAGE FAMILY
Emmenanthe penduliflora whispering bells
Tiquilia plicata plicate tiquilia
BRASSICACEAE MUSTARD FAMILY
Brassica sp.mustard
Brassica nigra*black mustard
CHENOPODIACEAE GOOSEFOOT FAMILY
Atriplex canescens four-wing saltbush
Chenopodium album*lamb's quarters
Salsola tragus*Russian thistle; tumbleweed
CUCURBITACEAE GOURD FAMILY
Cucurbita palmata coyote melon
Marah macrocarpa (= M. macrocarpus)wild cucumber
EUPHORBIACEAE SPURGE FAMILY
Croton setigerus (= Eremocarpus setigerus)dove weed
Ricinus communis*castor-bean
FABACEAE LEGUME FAMILY
Acacia sp.acacia
Melilotus indica*sourclover
Psorothamnus spinosus smoke tree
FAGACEAE OAK FAMILY
Quercus sp.oak
MYRTACEAE MYRTLE FAMILY
Eucalyptus sp.gum tree
NYCTAGINACEAE FOUR O'CLOCK FAMILY
ANGIOSPERMS (DICOTYLEDONS)
Abronia villosa sand verbena
Bougainvillea spectabilis bougainvillea
POLYGONACEAE BUCKWHEAT FAMILY
Rumex obtusifolius bitter dock
SOLANACEAE NIGHTSHADE FAMILY
Datura discolor jimson weed
Datura wrightii datura
Nicotiana glauca*tree tobacco
TAMARICACEAE TAMARISK FAMILY
Tamarix ramosissima*Mediterranean tamarisk
ZYGOPHYLLACEAE CALTROP FAMILY
Larrea tridentata creosote bush
Tribulus terrestris*puncture vine
POACEAE GRASS FAMILY
Cynodon dactylon*Bermuda grass
Pennisetum setaceum*fountain grass
TYPHACEAE CATTAIL FAMILY
Typha latifoilia broadleaf cattail
ANGIOSPERMS (MONOCOTYLEDONS)
* non-native species
Appendix B
Arid West Wetland Determination Data Forms
Appendix C
Site Photographs
Photo 1 – East side of the CVSWC within the Dune Palms Road low crossing area.
Photo 2 – West side of the CVSWC, looking up-stream to the west.
Photo 3 – Concrete drainage flowing south within the CVSWC to the west of Dune Palms Road.
Photo 4 – Dirt bed and bank with erosion rills running into the CVSWC, looking west from the
east side of Dune Palms Road.
Photo 5 – Corrugated metal pipes under Dune Palms Road and weathered concrete immediately
around the road, looking northwest from the east side of Dune Palms Road.
Photo 6 – Concrete bank to the southwest along the CVSWC.
Photo 7 – Sitting water with mostly non-native vegetation around the area, looking south in the
CVSWC to the east of Dune Palms Road.
Photo 8 – Overview of the area where the concrete drainage dissipates to, looking south across
the CVSWC.
Dune Palms Road Crossing Replacement Project - Natural Environment Study
Dune Palms Road Project NES 68
Appendix D – Email Correspondence with Agencies
1
Scott Taylor
From:Quinnell, Scott F@DOT <scott.quinnell@dot.ca.gov>
Sent:Monday, February 23, 2015 5:23 PM
To:Michael Tuma
Subject:RE: Dune Palms Road Crossing Replacement project
Hi Michael,
Great, would be happy to assist. The assigned CT biologist is Denesse Segura. 909‐806‐4727;
Denesse.Segura@dot.ca.gov If after discussing with her you need additional guidance, just let me know.
By the way, great presentation yesterday afternoon! I’m glad I stayed for the afternoon talks, but the traffic coming
home was no fun; I thought by staying later, I would avoid all of that, which I’m sure you hit too if you drove.
Scott Quinnell
Senior Environmental Planner
Environmental Stewardship & Monitoring Branch Chief
Biological Studies & Permits Branch (Acting Branch Chief)
Caltrans District 8
Office: (909) 383-6936
From: Michael Tuma [mailto:mtuma@ecorpconsulting.com]
Sent: Monday, February 23, 2015 5:12 PM
To: Quinnell, Scott F@DOT
Subject: Dune Palms Road Crossing Replacement project
Hi Scott,
I’m working with Lorraine Ahlquist at Parsons Brinkerhoff on completing an NES for the Dune Palms Road Crossing
Replacement project in La Quinta. I’d like to talk to you at some point in the near future to get an idea of your (or any
Caltrans biologist assigned to reviewing the NES) expectations for the report so that I’m preparing it accordingly.
Thanks,
Michael
Michael Tuma
Senior Biological Program Manager
ECORP Consulting, Inc.
215 N. 5th Street, Redlands, CA 92374
Ph: 909.307.0046 ♦ Cell: 626.390.5717 ♦ Fax: 909.307.0056
mtuma@ecorpconsulting.com ♦ www.ecorpconsulting.com
1
Scott Taylor
From:Sirchia, Felicia <felicia_sirchia@fws.gov>
Sent:Thursday, February 26, 2015 10:49 AM
To:Michael Tuma
Cc:John M Taylor
Subject:Re: Dune Palms Road Crossing Replacement
Hi Michael, are you planning any spring surveys? If so, and the plant is not detected, it likely does not occur in
the area since we had a few nice winter rain events.
If you're not planning spring surveys, you could include a conservation measure to conduct a pre-construction
survey (assuming timing of construction is conducive to detecting the plant).
In either case, you can insert some BMP's for milk-vetch in the NES that would include a worker education
program, on-site bio monitors, and avoidance measures.
Also, if the milk-vetch is detected on site and can't be avoided, the following measure could also be included:
The seeds of milk-vetch will be collected from plants from within the Project impact areas. Seed collection will
occur when the seed is past “soft dough” and prior to being naturally dispersed. The top 10 centimeters (4
inches) of soil surrounding the identified plants will be collected and placed in plastic bags. This seed and soil
will be distributed immediately following collection to either the Whitewater Floodplain Conservation Area or
Willow Hole Conservation Area. Caltrans will be coordinate with the Coachella Valley MSHCP’s Reserve
Management Oversight Committee (RMOC) to determine optimal dispersal sites.
If the plant is detected and avoidance of individual plants is achievable, then we would be able to do an
informal consultation under section 7 of the ESA. If it is not possible to avoid individuals, than a formal section
7 (i.e., BO) would be necessary but we would streamline this under the existing CV MSHCP permit since
Caltrans is a permittee.
Lastly, because Caltrans is a permittee and they have monetary obligations under the MSHCP that have not yet
been met, there should be a conservation measure in the NES addressing a minimum of 5 percent of the project
costs that goes towards Caltrans' obligations as identified in section 6.6.1 of the MSHCP.
Let me know if you have any other questions or need additional clarification.
--------------------------
Felicia M. Sirchia
Fish & Wildlife Biologist
U.S. Fish and Wildlife Service
Palm Springs Fish and Wildlife Office
777 E. Tahquitz Canyon Way, Suite 208
Palm Springs, CA 92262
Phone 760.322.2070 x205
Fax 760.322.4648
2
On Thu, Feb 26, 2015 at 9:09 AM, Michael Tuma <mtuma@ecorpconsulting.com> wrote:
Hi Felicia,
We’ve been to the Dune Palms Road project site a couple times over the past two months and have not yet seen
Coachella Valley milk‐vetch. However, we’re also hearing reports from the field that it’s not germinating in reference
populations this year (at least not yet). How would you like us to handle this in the NES? Would there be a need to a BO
in this case?
Thanks,
Michael
From: Sirchia, Felicia [mailto:felicia_sirchia@fws.gov]
Sent: Monday, December 08, 2014 4:50 PM
To: Michael Tuma
Subject: Fwd: Dune Palms Road Crossing Replacement
Hi Michael, I will be the lead biologist for this project. I will contact you in the next couple of days to touch
base with you regarding project needs in terms of addressing federally listed species.
Thanks!
--------------------------
Felicia M. Sirchia
Fish & Wildlife Biologist
U.S. Fish and Wildlife Service
Palm Springs Fish and Wildlife Office
777 E. Tahquitz Canyon Way, Suite 208
Palm Springs, CA 92262
3
Phone 760.322.2070 x205
Fax 760.322.4648
---------- Forwarded message ----------
From: Cleary-Rose, Karin <karin_cleary-rose@fws.gov>
Date: Fri, Dec 5, 2014 at 1:24 PM
Subject: Fwd: Dune Palms Road Crossing Replacement
To: John Taylor <john_m_taylor@fws.gov>, Felicia Sirchia <felicia_sirchia@fws.gov>
---------- Forwarded message ----------
From: Michael Tuma <mtuma@ecorpconsulting.com>
Date: Fri, Dec 5, 2014 at 11:40 AM
Subject: Dune Palms Road Crossing Replacement
To: "Karin_Cleary-Rose@fws.gov" <Karin_Cleary-Rose@fws.gov>
Greetings Karin,
I’m assisting Caltrans on a project in La Quinta that would entail constructing a bridge over the Whitewater
River channel at Dune Palms Road (project location maps attached). For developing the Biological Assessment
in support of a Section 7 consultation for the project, would you please send me a list of listed species that you
would like us to consider? Please also let me know if you need additional details about the project.
Thank you,
Michael
Michael Tuma
Senior Biological Program Manager
ECORP Consulting, Inc.
1
Scott Taylor
From:Sirchia, Felicia <felicia_sirchia@fws.gov>
Sent:Monday, December 08, 2014 4:50 PM
To:Michael Tuma
Subject:Fwd: Dune Palms Road Crossing Replacement
Attachments:Figures 1&2 Dune Palms.pdf
Categories:Follow Up / Respond, Be Aware
Hi Michael, I will be the lead biologist for this project. I will contact you in the next couple of days to touch
base with you regarding project needs in terms of addressing federally listed species.
Thanks!
--------------------------
Felicia M. Sirchia
Fish & Wildlife Biologist
U.S. Fish and Wildlife Service
Palm Springs Fish and Wildlife Office
777 E. Tahquitz Canyon Way, Suite 208
Palm Springs, CA 92262
Phone 760.322.2070 x205
Fax 760.322.4648
---------- Forwarded message ----------
From: Cleary-Rose, Karin <karin_cleary-rose@fws.gov>
Date: Fri, Dec 5, 2014 at 1:24 PM
Subject: Fwd: Dune Palms Road Crossing Replacement
To: John Taylor <john_m_taylor@fws.gov>, Felicia Sirchia <felicia_sirchia@fws.gov>
---------- Forwarded message ----------
From: Michael Tuma <mtuma@ecorpconsulting.com>
Date: Fri, Dec 5, 2014 at 11:40 AM
Subject: Dune Palms Road Crossing Replacement
To: "Karin_Cleary-Rose@fws.gov" <Karin_Cleary-Rose@fws.gov>
Greetings Karin,
I’m assisting Caltrans on a project in La Quinta that would entail constructing a bridge over the Whitewater
River channel at Dune Palms Road (project location maps attached). For developing the Biological Assessment
in support of a Section 7 consultation for the project, would you please send me a list of listed species that you
would like us to consider? Please also let me know if you need additional details about the project.
1
Scott Taylor
From:Ginny Short <athenas_owl@roadrunner.com>
Sent:Tuesday, February 24, 2015 6:31 PM
To:Michael Tuma
Subject:Re: CV milk-vetch
Hi Michael,
Nice to hear from you. We do have locations on the preserve where milkvetch can be found, but there has been almost
no rain this year. I can show you one in my backyard, but I don't know if any are blooming anywhere else in the
valley. Probably in pockets here and there, but I can't help you this year. Also, FYI, the locations I have them on the
preserve are closed to the public, so your folks would not be able to access them.
If I hear of any blooms I will let you know.
Ginny
On 2/24/2015 2:09 PM, Michael Tuma wrote:
Hi Ginny,
It’s been a while since we’ve worked together, and I was pleased to find out you’re managing a preserve
that has relevance to a project I’m working on. For the project (a road crossing over the Whitewater
River channel in La Quinta), I’m working on a rare plant survey to look for Coachella Valley milk‐vetch. I
want our biologists to get out to observe a known population/occurrence of this plant as part of this
effort, and Brad Haley recommended I contact you. Are there CV milk‐vetch occurrences on any of the
reserves you’re managing? If so, do you have location information that my biologists could use to access
them for their reference work?
Thanks,
Michael
Michael Tuma
Senior Biological Program Manager
ECORP Consulting, Inc.
215 N. 5th Street, Redlands, CA 92374
Ph: 909.307.0046 ♦ Cell: 626.390.5717 ♦ Fax: 909.307.0056
mtuma@ecorpconsulting.com ♦ www.ecorpconsulting.com
Dune Palms Road Crossing Replacement Project - Natural Environment Study
Appendix E – Project Area Photographs
Dune Palms Road Project NES 75
Dune Palms Road – Southern Side of Existing Low Flow Crossing
Dune Palms Road – Northern Side of Existing Low Flow Crossing
Dune Palms Road – Eastern Side of Existing Low Flow Crossing
Dune Palms Road – Western Side of Existing Low Flow Crossing
Freshwater Marsh Vegetation
Disturbed Riparian Herbaceous Vegetation in CVSWC
Disturbed Habitat
Developed Area
215 North Fifth Street ● Redlands, CA 92374 ● Tel: (909) 307-0046 ● Fax: (909) 307-0056 ● www.ecorpconsulting.com
October 17, 2017
2014-173
Mr. Aaron Burton
Senior Environmental Planner
Environmental Special Projects “C”
Department of Transportation, District 8
464 West Fourth Street, 6th Floor, MS 760
San Bernardino, CA 92401-1400
Via Email: aaron.burton@dot.ca.gov
RE: Update Jurisdictional Delineation Analysis for the La Quinta Dune Palms Road Low
Water Crossing Replacement Project (Federal Aid Project No. BRLKS-5433(014)),
Riverside County, California
Dear Mr. Burton,
This is a letter to file regarding recent revisions to the Dune Palms Road Low Water Crossing
Replacement Project (Project), with regard to the analysis contained in the Project Natural
Environment Study (NES), to address changes to the Project footprint and their effects primarily on
jurisdictional delineated waters. ECORP Consulting, Inc. (ECORP) completed the last revision of the
NES in October of 2015. For reference, the Project is located within the City of La Quinta within the
Coachella Valley (Attachment A, Figures 1 and 2).
INTRODUCTION
The 2015 NES report included a description of the site, the watersheds, the soils, and the
jurisdictional features, description of agency consultation with regard to listed plant and animal
species, results of a rare plant survey and a full analysis of the Project impacts. Jurisdictional features
delineated within the Project footprint included the Coachella Valley Storm Channel
(CVSC)/Whitewater River and a storm channel outlet on the north side of the low flow crossing
(Attachment A, Figure 3). The CVSC channel was considered to be a non-wetland Water of the U.S.
and Water of the State while the storm channel outlet supported a wetland Water of the U.S. and
additional jurisdictional Water of the State.
The majority of the Project as described in the NES is still valid. Changes made to the Project are
discussed below. A full description of the revised Project is included in Attachment B.
Slope Protection
With further development of the design plans, it became apparent that there was a need to extend
the slope protection limits to provide scour countermeasures. Slope protection is a necessary part of
the Project The outlet will be removed and relocated to the north (away from the center of the
Mr. Aaron Burton Page 2 of 5
Caltrans, District 8 November 3, 2017
channel) to align with the proposed slope protection. However this extension will affect the outlet of
the existing storm drain where a jurisdictional wetland is present.
The relocated storm drain outlet will be constructed to be integral with the proposed slope
protection and re-established to be close to pre-project dimensions after construction has been
completed. The installation of the concrete slope protection will require the existing channel bank to
be excavated at a 1.5:1 (horizontal to vertical) slope to the bottom of the channel, then at a 1:1 slope
to the bottom of the slope protection. The current dirt channel bank is at an approximate slope of
2:1 to 2.5:1
Construction Access and Staging
In addition, due to the need for construction access to the work areas, there will be temporary use of
more areas within the non-wetland, unvegetated CVSC channel for construction operations, but no
storage of equipment and/or materials in the channel bottom.
And finally, the Project staging in a nearby vacant lot has been confirmed and will be offered to the
contractor by the City in the bidding documents to be used for storage and construction staging.
This staging area was contemplated in the NES, and the refinement only serves to refine the area to
be used for staging.
METHODS
For this letter, we used the original jurisdictional delineation for the Project, which conformed to the
unified federal method, as defined by the U.S. Army Corps of Engineers (USACE), using methodology
outlined in the Corps of Engineers Wetlands Delineation Manual (USACE 1987) and the Regional
Supplement to the Corps of Engineers Wetland Delineation Manual: Arid West Region (Arid West
Region Supplement Version 2.0; USACE 2008). The delineation report is included in the NES.
RESULTS
Jurisdictional Areas
The storm channel that is located to the northwest of Dune Palms Road, and supports a wetland
area, will be impacted by the slope protection extension for the Project, totaling 422 square feet
(0.01 acre) and 53 linear feet of temporary impacts. Temporary construction access within the CVCS
will increase temporary impacts to non-wetland Waters of the U.S. by 0.08 acre and 20 linear feet
(Attachment A, Figure 4). The revised impact totals are provided below in Table 1.
Table 2: Potential USACE Jurisdictional Area Impacts
Geomorphic Feature Impacts (Acres/Linear Feet)
Temporary Permanent
Intermittent Stream
(CVSWC) 0.13/32 0.02/5
Wetland 0.01/53 0/0
Total 0.14/85 0.02/5
Mr. Aaron Burton Page 3 of 5
Caltrans, District 8 November 3, 2017
The additional impacts also include CDFW and RWQCB jurisdictional areas as summarized in Table 3.
Table 3: Potential CDFW and RWQCB Jurisdictional Area Impacts
Geomorphic Feature Impacts (Acres/Linear Feet)
Temporary Permanent
Intermittent Stream
(CVSWC) 0.13/32 0.02/5
Wetland 0.01/53 0/0
Total 0.14/85 0.02/5
Because the additional impacts are considered temporary, and because the temporary impact areas
are expected to return to their current state and size post-Project, no mitigation is being proposed
for these new impacts. The change in impacts does not alter the analysis within the NES, as the
following approvals/ permits still must be obtained or determined not applicable by the applicable
Federal and State resource agencies:
• Streambed Alteration Agreement pursuant to California Fish and Game Code Section 1602;
• USACE Nationwide Permit pursuant to Clean Water Act Section 404; and RWQCB 401 Water
Quality Certification pursuant to Clean Water Act Section 401.
Special Status Plant Species
Based on the analysis within the NES, there is no suitable habitat for the Coachella Valley milk vetch
or the species’ Critical Habitat anywhere with the Project area. No additional impacts from the
Project are anticipated at this time to other sensitive plant species. With incorporation of the existing
avoidance measures identified within the NES, special-status plant species impacts are avoided and
minimized.
Special Status Animal Species
Based on the analysis for animal species within the NES, no listed special-status animal species would
be impacted by the proposed Project. The revisions to the Project for slope protection and
temporary construction access do not change this analysis. The only potential impacts identified for
the Project on special-status animal species were limited to nesting bird species and burrowing owls.
With incorporation of the existing avoidance and mitigation measures identified within the NES, no
additional impacts to special-status animal species are anticipated due to the revised Project impact
area. The survey area for pre-construction surveys will need to encompass all areas of the Project,
including the revised Project area.
CONCLUSION
This letter provides new information regarding impacts to wetland Waters of the U.S. and Waters of
the State due to revisions in the Project that were not previously identified. The update of the
Mr. Aaron Burton Page 4 of 5
Caltrans, District 8 November 3, 2017
jurisdictional delineation impact analysis determined that the Project will impact non-wetland Waters
of the U.S./State within the CVSC totaling 0.13 acre and 32 linear feet of temporary impacts and 0.02
acre and 5 linear feet of permanent impacts. The Project would incur an additional temporary impact
to wetlands of 0.01 acre and 53 linear feet. No additional mitigation is being proposed for these
impacts because of the temporary nature of the impacts. Therefore the analysis contained within the
NES with regard to regulatory permitting requirements is still valid for the impacts to jurisdictional
features, which require the following permits and propose no mitigation:
• Streambed Alteration Agreement pursuant to California Fish and Game Code Section 1602;
• USACE Nationwide Permit pursuant to Clean Water Act Section 404; and RWQCB 401 Water
Quality Certification pursuant to Clean Water Act Section 401.
Measures identified within the NES to minimize and avoid impacts (BMPS, establishment of ESAs,
and so on) remain valid and applicable to the increased impact areas.
No additional impacts to special status species were identified as a result of the revised Project
configuration, and no additional species mitigation is needed beyond that which is already discussed
within the NES. However the proposed pre-construction surveys for special status animal species
must encompass the revised Project area.
If you have any further questions or needs for clarification regarding the project, please contact
me at (909) 307-0046.
Sincerely,
Scott I. Taylor
Senior Biologist/Regulatory Permitting Manager
Mr. Aaron Burton Page 5 of 5
Caltrans, District 8 November 3, 2017
REFERENCES
Baldwin BG, Goldman GH, Keil DJ, Patterson R, Rosatti TJ, Wilken DH. 2012. The Jepson
Manual; Vascular Plants of California, Second Edition. Berkeley, CA: University of
California Press.
[ECORP] ECORP Consulting, Inc. 2015. Natural Environment Study and Jurisdictional Waters
Delineation for the Dune Palms Road Low-Water Crossing Replacement Project in the
City of La Quinta, Riverside County, California. Prepared for California Department of
Transportation. October 2015.
[USACE] U.S. Army Corps of Engineers. 1987. Corps of Engineers Wetlands Delineation
Manual. Technical Report Y-87-1. U. S. Army Engineer Waterways Experiment Station.
Vicksburg, Mississippi.
USACE 2008. Regional Supplement to the Corps of Engineers Wetland Delineation Manual:
Arid West Region (Version 2.0). ed. J.S. Wakeley, R.W. Lichvar, and C.V.
Attachment A – Figures
Attachment B – Revised Project Description
Project Description
Project Purpose
The purpose of the project is to replace the existing low-water crossing spanning the Coachella
Valley Storm Water Channel (CVSC) at Dune Palms Road with an all-weather access. The
proposed improvements will accomplish the following objectives in the project area:
1) Provide safe access across the CVSC (Whitewater River) during all-weather events
2) Provide reliable route for emergency vehicles, motorists, pedestrians, and bicyclists
3) Achieve the City’s General Plan goals for the corridor
Project Need
Dune Palms Road serves a vital access for emergency services within the project area, as well as
for La Quinta High, John Glenn Middle and Amelia Earhart Elementary Schools. It also provides
connectivity of the city residential development north of the Channel with the Highway 111
commercial corridor located south of the CVSC. (See Figures 1 and 2 for Vicinity and Location
Maps)
The CVSC conveys storm water runoff from the surrounding mountains as well as developed
areas within the Coachella Valley. The elevation of the existing Dune Palms Road low-water
crossing causes it to flood during minor rain events (2-year frequency) and results in full street
closure and detour of both vehicle and pedestrian traffic. In the interest of public health and
safety, and in response to community concerns regarding frequent closures of the low-water
crossing, the City of La Quinta has determined that replacement of the low-water crossing with
a new bridge is needed to ensure that all-weather access is maintained. The Dune Palms Road
low-water crossing is the last remaining low-water crossing of the CVSC within the City.
Existing Conditions
The existing roadway crosses the CVSC at the channel grade. The roadway width is 68 feet at
the crossing, and consists of one northbound and two southbound through lanes, eight foot
wide walkway area along the western edge, and an eight foot shoulder along the eastern edge
of the road; and no median. The existing roadway approach south of the crossing consists of
one northbound and two southbound through lanes. The northern roadway approach consists
of one through lanes in each direction. The transition from one to two lanes in the southbound
direction occurs at the midpoint of the channel crossing. Dune Palms Road approximately one-
quarter mile north of the channel low-water crossing and just south of the project limits is a
four lane roadway with a median. The roadway section just north of the crossing will be
widened as part of an approved City project. The project was originally approved with a
Mitigated Negative Declaration under CEQA in April 2010.
Proposed Improvements
The project proposes to remove the existing low-water crossing of Dune Palms Road at the
CVSC in the City of La Quinta, Riverside County. The crossing will be replaced with a 480 feet
long and 86 feet wide four-span bridge. The bridge typical section consists of six-foot sidewalk
on both sides of the bridge, two (2) eight-foot outside shoulders also serving as bike/golf cart
lanes, a 10 foot raised median, two (2) eleven-foot travel lanes, and two (2) twelve-foot travel
lanes.
The proposed configuration will be consistent with the existing four lane roadway section to the
south, and the City’s current improvement project to the north (project number 2009-04),
which will widen Dune Palms Road from two to four lanes with a median and left turn lanes.
The proposed improvements will include a reconstruction of the north and south bridge
approaches to accommodate the significant raised profile of the roadway to accommodate the
required bridge elevation. In order to match the roadway section on the south side of the
bridge, the project’s construction limits will be extended to 239 feet north of Highway 111. On
the north side of the bridge, the APE is extended along Dune Palms Road to the north and
includes a portion of the vacant lots (portions of APN 600-030-004 & 600-030-021)
approximately 850 feet north of the storm water channel. The vacant lot is owned by the City’s
Housing Authority and will be offered by the Authority in the bidding documents to be used for
storage and construction staging by the contractor for the construction of this project.
As a part of the bridge construction, concrete slope protection will be installed at the northwest
and southeast corners of the bridge. The slope protection at the northwest corner will extend
approximately 200 feet upstream and at the southeast corner approximately 350 feet
downstream. Additionally, minor removal and replacement of slope protection will be required
at both the northeast corner to address scour associated with the bridge and at the southwest
corner of the bridge to address bridge scour as well as an undercrossing for CV Link. As
previously noted the slope protection is needed for scour countermeasures. As a result of the
proposed cast-in-place drilled shaft bridge construction, scour protection within the bottom of
the channel should not be required. Associated with the extension of the slope protection in
the NW corner of the proposed bridge, the outlet of the existing storm drain will be relocated
to the north (away from the center of the channel) to align with the proposed slope protection.
The relocated storm drain outlet will be constructed integral with the proposed slope
protection. The installation of the concrete slope protection will require the existing channel
bank to be excavated at a 1.5:1 (horizontal to vertical) slope to the bottom of the channel, then
at a 1:1 slope to the bottom of the slope protection. The current dirt channel bank is at an
approximate slope of 2:1 to 2.5:1
Due to the lack conveyance structures at the existing low water crossing acting, sediment has
been deposited on the upstream side of the channel from Dune Palms Road since the original
construction. Additionally, on the downstream side of the crossing, the channel has an area of
scour. Therefore, the elevation differential between the upstream and downstream channel
bottom approximately eleven (11) feet. The project will grade the bottom of the channel 300
feet west and east, up and downstream respectively, of the crossing to provide a uniform
channel bottom slope within the project area.
The project will also include the following additional improvements:
• Railing Architectural treatment. The bridge design will incorporate railing architectural
treatment as required by the City’s standard design.
• Integration of a regional Bike/Pedestrian/Neighborhood Electric Vehicle (NEV) corridor (CV
Link). The Coachella Valley Association of Governments (CVAG) and the communities within
the Coachella Valley are working together on the implementation of a regional
Bike/Pedestrian/NEV corridor (CV Link) along Whitewater River and Coachella Valley Storm
Water Channel. The project design will be consistent with these plans by allowing for the
integration of a trail under crossing within the southern slope protection, which also
includes a trail connector to the pedestrian and bike facilities proposed along Dune Palms
Road in the project area.
• Utility Relocation. The project will also require utility relocations for Imperial Irrigation
District (IID) overhead electrical distribution lines, adjustment to both water valve can and
lids and the manhole covers, 18” ductile iron pipe water main relocations at each bridge
abutment, and relocation of both a 12” and 18” sewer line at the northern bridge
abutment. Both the water main and sewer line, under the operations of Coachella Valley
Water District (CVWD), relocations would be minor in nature, with the relocation limited to
the existing road right and/or channel of way.
Right-of-Way Requirements
The project will require street right-of-way acquisitions on the northeast and southeast corners
of the proposed bridge. The existing development at the northeast corner of the proposed
bridge consists of a mobile home park with one single family home. Some of the mobile homes
adjacent to the Dune Palms Road are encroaching within the existing street right of way. The
project may require the acquisition of the single-family residence and relocation of two mobile
homes residents. The project will be designed to avoid and minimize relocation impacts of the
mobile homes.
Temporary Construction Bypass
The existing roadway will be modified to construct a temporary construction bypass road. The
temporary bypass will allow for staged construction of the bridge, and maintaining vehicle and
pedestrian access at all times. Temporary and short term access impact may occur during
construction, and will require coordination with property owners, the public, and other
stakeholders.
Map Date: 3/25/2015Photo Source: Esri Figure 3.Jurisdictional Delineation
2014-173 La Quinta Dune PalmsLocation: N:\2014\2014-173 La Quinta Dune Palms\MAPS\Wetland_Mapping\Wetland_Delineation\v1\LQDP_JD_V1.mxd (MAG)-mguidry 3/25/2015 !>!>
Coachella Val
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Temporary Construction Easement
!>Sample Point
Existing Low Flow Crossing
Waters of the US / State
Intermittent Stream / Streambed(2.20 ac - 490 linear feet)
Wetland / Freshwater Marsh(0.28 acres - 15 linear feet)
I
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Scale in Feet
Dune Palms Rd.Pro jec t Lo c atio n
Indio
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Figure 2. Project Locatio n
2014-17 3 La Quin ta D une Pa lm s
Map D ate : 2/23/2015Source: ESRILocation: N:\2014\2014-173 La Quinta Dune Palms\MAPS\Location_Vicinity\LQDP_Location.mxd (MAG)-mguidry 2/23/2015 I
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M i l e s
Pro jec t Lo c atio n
S a n B e r n a r d i n oNational F o r e s t
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Figure 1. Project Vicinity
2014-17 3 La Quin ta D une Pa lm sLocation: N:\2014\2014-173 La Quinta Dune Palms\MAPS\Location_Vicinity\LQDP_Vicinity.mxd (MAG)-mguidry 2/23/2015 Map D ate : 2/23/2015Service La ye r C re dits : Sou rces: USGS, E SRI, TANA, AND
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UTUT
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Size of printing extent and margins differs with printer settings, please adjust margins if necessary.MAP REQUI RES A MAPLEX LICENSENOTE: This map is set up in NAD 1983 California Teale Albers.Please Change to Define Your Local State Plane or UTM Coordinate System.
I
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M i l e s
Figure 4