HomeMy WebLinkAboutDune Palms_ Floodplain EncroachmentSUMMARY FLOODPLAIN ENCROACHMENT REPORT
Dist. 08 Co. Riverside Rte. Local Assistance, City of La Quinta
Project No.: BLRKS-5433(014)Bridge No. NA
Limits: Dune Palms Road from approximately 220 feet north of Highway 111 to 950 feet
south of Blackhawk Way/Westward Ho Drive, crossing the Coachella Valley Storm
Water Channel.
Floodplain Description:The Whitewater River Basin is located approximately 100 miles
east of Los Angeles. The watershed drains to the Salton Sea located about 23 miles south
of the project site. The tributary area of the watershed is made up of a broad desert valley
(Coachella Valley) between two mountain ranges; the San Bernardino and Little San
Bernardino Mountains form the northeast boundary of the watershed, the San Jacinto
Mountains form the southeast boundary. Upstream from the vicinity of Washington Street
(Point Happy) the channelized section of the Whitewater River is referred to as the
Whitewater River Storm Water Channel (WWRSC); downstream to the Salton Sea, this
channelized section is named the Coachella Valley Storm Water Channel (CVSC).
No Yes
1. Is the proposed action a longitudinal encroachment of the base floodplain? X ___
2. Are the risks associated with the implementation of the proposed action
significant?
X ___
3. Will the proposed action support probable incompatible floodplain
development?
X ___
4. Are there any significant impacts on natural and beneficial floodplain values? X ___
5. Routine construction procedures are required to minimize impacts on the
floodplain. Are there any special mitigation measures necessary to minimize
impacts or restore and preserve natural and beneficial floodplain values? If
yes, explain.
X ___
6. Does the proposed action constitute a significant floodplain encroachment as
defined in 23 CFR, Section 650.105(q).
X ___
7. Are Location Hydraulic Studies that document the above answers on file? If
not explain.
___ X
PREPARED BY:
______________________________________ 02/24/2015
Signature - Hydraulic Engineer Date
______________________________________
Signature - Environmental Manager Date
______________________________________ 02/24/2015
Signature - Project Engineer Date
4/2/2015