Final Baseline Hydrology Report - October 2012 - Urban Drainage ...

Sanderson Gulch Major Drainageway Plan
Baseline Hydrology Report October 2012
Maintenance. Maintenance of Kendrick Lake Park is the responsibility of the City of Lakewood and occurs
on a regular schedule for the manicured turf areas and park amenities. Mowing practices typically occur
once or twice during the growing season for the non-irrigated dryland grass areas. There are no UDFCD
maintenance responsibilities through Reach 12.
Parks and Recreation. Smith Reservoir includes a gravel loop trail around the reservoir, but there is no
public access to the water. Kendrick Lake Park is 58 acres, including the reservoir surface area, and
includes park and recreation facilities that include a paved parking lot, restrooms, demonstration gardens,
picnic shelters and a playground. A continuous gravel loop trail around the reservoir provides pedestrian
and fishing access.
Water Quality. Smith Reservoir and Kendrick Reservoir provide passive water quality treatment.
North Sanderson Gulch
Reach NS1 – Sanderson Gulch Confluence to S. Pierce Street (Lakewood)
Landscape and Ecology. This reach is dominated by heavy riparian vegetation species including
cottonwood, willow and rushes. A large wetland pond area with some riparian species exists in the middle
of the Greenbelt. Upland species of non-irrigated dryland grasses are predominantly wheatgrass and
fescue. Invasive species (thistle, kochia, smartweed, bindweed, prickly lettuce, common mallow, barnyard
grass, Johnsongrass, pigweed, rag weed, curly dock, halogeton, redstem filaree, alfalfa, Siberian elm,
Chinese elm and Russian olive) are present, especially in the open non-irrigated upland areas.
Maintenance. The White Fence Farm Filing No. 1 channel reach from the wetland pond to the confluence
is eligible for UDFCD maintenance. The City of Lakewood maintains the reach between S. Harlan Circle
and S. Pierce Street, with routine maintenance assistance from UDFCD.
Parks and Recreation. The Sanderson Gulch Greenway is owned by the City of Lakewood and includes a
continuous concrete pubic bike/pedestrian access with at-grade crossings.
Water Quality. The Sanderson Gulch Greenway wetland pond provides passive water quality treatment.
Reach NS2 – S. Pierce Street to Wadsworth Boulevard (Lakewood)
Reach NS1 is approximately 2,800 feet long and extends upstream from the confluence with Sanderson
Gulch to S. Pierce Street. The 2009 North Sanderson Gulch Greenbelt Improvements project stabilized the
channel and included a large wetland pond area. The channel in this reach is contained in a narrow openspace
corridor mostly less than 100-feet in width. It is recently stabilized with 11 relatively new grouted
boulder drop structures but has an unlined invert and typically vegetated soil riprap banks. There is a very
small, intermittent base flow in the lower portion of the reach and standing water in the small ponds and
drop stilling basins. All of the existing drop structures and most channel banks are in good condition. A
continuous concrete pedestrian path exists in the reach and the lower third has a path on both sides of the
channel. The road crossing on S. Harlan Circle has 100-year capacity.
The character of North Sanderson Gulch changes
significantly in several ways at S. Pierce Street. The more
open, aesthetic, drainageway with continuous public access
and relatively new, 100-year drainage facilities downstream
changes at S. Pierce Street to a 30-foot width constructed
channel with a concrete invert, steep gabion mattress banks
and no public access through Reach NS2. The small base
flows which exist downstream disappear above S. Pierce
Street. The concrete channel invert has deteriorated in
many areas and the four bridge crossings at Pierce, Quay,
Upham and Calahan have only approximately 10-year
capacity with numerous adjacent residential structures in
the floodplain. Significant improvements to the existing
drainage facilities are recommended in this reach.
Channel downstream of Wadsworth.
Concrete pan and drop structure.
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