HomeMy WebLinkAboutDune Palms Community Impact MemoDune Palms Road Low-Water Crossing Replacement Project 1
M e m o r a n d u m
To: Sean Yeung, Acting Office Chief Date: February 13, 2018
Planning and Local Assistance
464 West 4th Street, 6th floor, MS 760
San Bernardino, CA 92401-1400
File: 08-Riv-Local Assistance
Dune Palms Road Crossing
Replacement Project
FPN: BLRKS-5433 (014)
From: Edward J. Wimmer, P.E.
City of La Quinta
Subject: Dune Palms Road Low-Water Crossing Replacement Project – Preliminary Community
Impact Memorandum focused on the Impacts at the Dune Palms Mobile Estates (46400
Dune Palms Road)
The Proposed Project:
This memorandum specifically addresses the impacts to the Dune Palms Mobile Estates located at 4600
Dune Palms Road (APN 6000030010) caused by the Dune Palms Road Low-Water Crossing Replacement
Project.
The City of La Quinta is proposing to replace the existing low-water crossing spanning the Coachella
Valley Storm Water Channel (CVSWC) at Dune Palms Road with an all weather access bridge (Figure 1).
Dune Palms Road serves a vital north/south link for emergency services, as well as access to La Quinta
High School, John Glen Middle School and Amelia Earhart Elementary School. It also provides
connectivity to the Highway 111 commercial corridor for residential development north of the channel.
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 proposed project would replace the existing roadway with a 480-foot long by 86-foot wide three-
span bridge. The bridge typical-section would consist of six-foot sidewalk on both sides of the bridge,
two eight-foot outside shoulders (also serving as bike/golf cart lanes), a 10 foot raised median, two 11-
foot travel lanes, and two 12-foot travel lanes. The proposed bridge would have an increased roadway
width as compared to the existing roadway in order to accommodate the raised median; however, the
proposed configuration would be compatible with the existing four-lane roadway section to the south,
and the City’s current roadway improvement project to the north. In order to meet the Coachella Valley
Water District hydraulic requirements, the bridge would have a significant vertical grade raise. The
existing roadway approaches would be reconstructed to accommodate the raised profile effectively
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Dune Palms Road Low-Water Crossing Replacement Project 2
extending the project’s construction limits to Highway 111 south of the project and to a vacant lot north
of the project (Figure 2). The vacant lot is owned by the City and may be used for storage and
construction staging.
As a part of the bridge construction, concrete slope protection would be installed along the north side of
the channel. Likewise, minor removal and replacement of slope protection would be required on the
south side of the channel, west of the proposed bridge, and extension of slope protection approximately
300-feet downstream of the proposed bridge. Based on current design, scour protection within the
channel bottom is not anticipated. Additionally, the Coachella Valley Association of Governments and
the communities within the Coachella Valley are working together on the implementation of a regional
Bike/Pedestrian/NEV corridor along Whitewater River / CVSWC. In accordance with this plan, the project
would be designed to allow for the integration of a trail under-crossing within the southern slope
protection. The project would also include a trail connector to the pedestrian and bike facilities along
Dune Palms Road. Dune Palms is identified for Class III Bicycle Paths (shared facilities) in the City’s
General Plan. The CVSWC shows a multi-use path and Dune Palms is also part of the Class II and III Golf
Cart/NEV Paths system.
The project would require right-of-way acquisition on the northeast and southeast corners of the
proposed bridge. The northeast corner is developed with one single-family home and a mobile-home
park all within the same parcel (Photo 7); the property at the southeast corner is vacant (Photo 8). The
project is being designed to avoid full acquisition and relocation of the affected residences pending
approval by the property owners of a partial property acquisition and access modification.
Existing Setting:
Dune Palms Road is oriented in a north-south direction and consists of one northbound and two
southbound through lanes at the crossing and southern approach. The northern roadway approach
consists of one through lane in each direction. The transition from one to two lanes in the southbound
direction occurs at the midpoint of the channel crossing. The roadway consists of two-lanes in each
direction between Fred Waring Drive and Westward Ho Drive (north of the proposed project), and
between Highway 111 and Avenue 48 (south of the proposed project). According to the City 2035
General Plan Circulation Element, current traffic volumes range from 10,000 to 12,000 vehicles per day
along this section of Dune Palms Road. Intersections with Dune Palms are operating at level of service C
and roadway segments operated at level of service A, and bicycles are accommodated via a Class III
Bicycle Path.
The Dune Palms Mobile Estates neighborhood includes 103 mobile homes with an on-site swimming
pool amenity, and one traditional single-story single-family home at the southwest corner of the site
facing Dune Palms Road, abutting the north side of the CVSWC.
The approximate density of the Dune Palms Mobile Estates neighborhood is 9.2 dwelling units per acre
based on a total of 104 dwelling units located on the 11.29-acre parcel. According to information
obtained on Zillow.com (December 23, 2014), the 103 mobile homes typically range in age from the mid-
1960’s to the mid-1990’s, the majority of the homes range in size from approximately 600 square feet to
1,200 square feet in area.
Two of the individual mobile homes along the Dune Palms Road frontage are approximately 20-feet
from the edge of pavement and currently encroach into existing right-of-way. They each have a six-foot
wood fence which is located approximately 10-feet from the edge of pavement which provides the only
buffer from traffic along Dune Palms Road. The entrance/exit points to the Dune Palms Mobile Home
Estates are via narrow driveways with limited visibility, especially when approaching the entrance rising
out of the at-grade crossing of the wash.
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Dune Palms Road Low-Water Crossing Replacement Project 3
The 11.29-acre parcel has a City of La Quinta General Plan land use designation of Medium/High Density
Residential. A summary of the General Plan Land Use Designation and Physical Land Use on the
surrounding parcels is noted in Table 1:
TABLE 1
Land Uses of the Surrounding Area
General Plan Designation Physical Land Use
North Medium/High Density Residential Bermuda Dunes Desert View Kingdom
Hall church; and vacant land
South Open Space- Natural Coachella Valley Storm Water
Channel/Whitewater River
East Low Density Residential Single-family residential neighborhood
West Major Community Facility La Quinta High School
The single-family residential neighborhood located immediately to the east of Dune Palms Mobile
Estates was built in 1989/90 based on data available on Zillow.com (December 23, 2014). Lot sizes
within this neighborhood range from 9,500 to over 10,000 square feet; and home sizes range from
approximately 1,400 to over 2,500 square feet in area.
The Bermuda Dunes Desert View Kingdom Hall church is located immediately north of the Dune Palms
Mobile Estates. The church site includes two separate structures separated by a common parking lot.
North of the church are nine separate parcels, eight of which are vacant, and one single-family residence
(built in 1986) which faces Westward Ho Drive.
On the west side of Dune Palms Road is the La Quinta High School. The Dune Palms Road frontage
includes views of sports fields and portable classrooms, with access to a parking lot. The main access to
the high school is from Westward Ho Drive.
Regulatory Setting:
The Medium/High Density Residential Land Use designation allows up to 16 dwelling units per acre and
is designed to accommodate a broad range of residential land uses, including small-lot subdivisions,
duplex, condominiums and apartment projects. Under the current General Plan and Zoning Ordinance
mobile home parks are allowed with the approval of a Conditional Use Permit.
According to the City Zoning Ordinance (Table 9-2 Residential Development Standards) the standard
front yard setback in the Medium/High residential district is 20-feet. In addition, development
standards for new Mobile Home Parks in Section 9.50.010 require a landscaped buffer of 20-feet
minimum around the perimeter of the entire project.
Project Consequences:
The right-of-way needs for the proposed roadway improvement and bridge construction project will
result in the acquisition of one single-family residence and two mobile homes, all of which are located
within the Dune Palms Mobile Estates neighborhood along the east side of Dune Palms Road. The
impacted residences are located on a single 11.29-acre parcel under the ownership of Chin Family
Survivors Trust per Quitclaim deed dated 11/23/2005.
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Dune Palms Road Low-Water Crossing Replacement Project 4
It is unknown at this time to what extent the residents of the three affected homes have property rights
via leases or similar documents affecting the property. It is assumed that the three affected residences
will require compensation for loss of the homes and any rights they may have in the land area, as well as
relocation assistance. The project’s proposed right-of-way requires only partial use of the parcel upon
which the residence and mobile homes are located. Pending approval by the property owners of partial
property acquisition and access modification, the project will be designed to avoid impacts by relocating
the mobile homes within the same area of the park if possible. Other options include relocation within
other vacant lots in the same park or nearby parks. The project will comply with the requirements of the
Uniform Relocation Assistance and Real Property Acquisition Policies Act. The City would also be
required to pay fair market value for any property which is acquired in order to complete the public
improvements.
Construction Impacts
During construction, the existing roadway would be modified as a temporary bypass to allow for staged
construction of the bridge, and to maintain vehicle and pedestrian access at all times. Temporary and
short term access impacts may occur and would require coordination with property owners, the public,
and other stakeholders to avoid and minimize such impacts.
The Dune Palms Road improvements will result in temporary vibration and elevated noise levels
associated with heavy equipment which will be used to grade and pave the roadway. Construction
noise is regulated by the City Municipal Code to occur during daytime hours only which service to
minimize potential impacts.
The construction activities may also be subject to soil erosion due to the effects of wind and water. The
City and the contractor will implement Management Plans for the control of erosion in accordance with
City and State regulations. The Management Plans will identify Best Management Practices (BMPs) that
must be implemented in order to control storm water run-off during construction activities.
The project will result in air emissions associated with grading and related construction activities.
Implementation of South Coast Air Quality Management District rules to regulate emissions and fugitive
dust will effectively minimize impacts to the local residents during this period.
Cumulative Impacts
In addition to the Dune Palms Road Low-Water Crossing Replacement Project, the City of La Quinta
previously approved a separate Dune Palms Road Widening Project (Project Number 2009-04). That
project included Environmental Assessment 2010-609 which was acted on by City Council on April 20,
2010. The purpose of the Dune Palms Road Widening Project is to widen the east side of the road, a
distance of approximately 1,200-feet, to the ultimate General Plan width as a Secondary Arterial
roadway. The project limits are between Westward Ho Drive and the CVSWC and consists of a 12-foot
travel lane, curb, gutter, and 6-foot sidewalk – the width of the improvements totaling approximately
20-feet. This project is currently at 90% design.
Since the CEQA analysis for the Dune Palms Road Widening Project was prepared prior to the initiation
of the Dune Palms Road Low-Water Crossing Replacement Project, it only addresses impacts of the Road
Widening Project. The CEQA Checklist identified “Less than Significant” impacts related to the potential
displacement of people and/or housing units as noted:
The widening of Dune Palms Road may require the removal or relocation of four mobile homes,
and recreational facilities in the mobile home park common area, which appear to be encroaching
into the City’s right of way. The engineering for the project will verify whether the structures are
encroaching into the right of way, and if so, whether they will need to be removed. In addition, the
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Dune Palms Road Low-Water Crossing Replacement Project 5
widening of the roadway may result in the need for the City to purchase the single-family home at
the southern end of the project. Assuming that they do need to be removed, the four mobile home
units and one single family home do not represent a substantial number of units, and the removal
of those units would not necessitate the construction of replacement housing elsewhere,
particularly since housing is available throughout the community, either in traditional construction,
or in other mobile home parks in the general vicinity.
Two of the four mobile homes and the single family home within the Dune Palms Mobile Estates which
are noted in the Dune Palms Road Widening project CEQA document, are the same as those related to
the Dune Palms Road Low-Water Crossing Replacement Project. The combined relocation impact of the
two projects is not substantial and will be avoided and minimized. Therefore the project is not
considered to have cumulative impacts.
Conclusion
The project will have minimal individual and cumulative community impacts. The project’s right-of-way
requirements will affect two mobile homes and one single family residence. However, avoidance and
minimization of effects will be accomplished by 1) relocation of the existing mobile homes on-site or off-
site to mobile home parks within the general project’s vicinity; and/or 2) relocation of the resident to
other housing accommodations either on-site or off-site. The overall impacts to the residents of the
Dune Palms Mobile Estates would largely be temporary and short term related to construction activities.
Construction impacts will be avoided and minimized by implementing applicable measures required by
ordinance, rules, and regulations. In addition, measures will coordinated with the local community,
utility companies, and any other affected parties. The project will be beneficial to local community and
residents of the mobile park as a result of enhancing safety conditions and providing all-weather
crossing. In addition, the removal of the mobile homes on the north and south side of the entry/exit
driveways may provide an opportunity to widen both the entry and exit driveways, enhancing safety and
improving access to the neighborhood.
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Figure 1: Vicinity Map
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Figure 2: Site Map
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Figure 3: Photo Location Map
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Dune Palms Road Low-Water Crossing Replacement Project 9
Photo 1: Vacant land southeast of Dune Palms Road Photo 2: Commercial buildings southwest of Dune Palms Road
Photo 3: La Quinta High School northwest of Dune Palms Road Photo 4: Single-family home and mobile-home park northeast of
Dune Palms Road
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Dune Palms Road Low-Water Crossing Replacement Project 10
Photo 5: Dune Palms Road looking west along the channel Photo 6: Dune Palms Road looking south
Photo 7: Single-family residence and mobile-home park northeast
of Dune Palms Road and the channel
Photo 8: Vacant lot southeast of Dune Palms Road and the
channel