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

Sanderson Gulch Major Drainageway Plan
Baseline Hydrology Report October 2012
Reach 6 – Sheridan Boulevard to Confluence with North Sanderson Gulch (Lakewood)
Maintenance. Through the privately owned Bit-O-Sea reach, the adjacent homeowners associations are
responsible for the maintenance of the drainageway. The improved drainageway for the White Fence Farm
Filing 1 through the Wilson Family Park and Clairefield Reservoir area is eligible for UDFCD maintenance.
Parks and Recreation. The Wilson Family Park is comprised of 13.16 acres, of which 1.62 acres are
devoted to the permanent pool of the reservoir, based on GIS data. The park is predominantly non-irrigated
natural area, with the bike/pedestrian path on the north side of the channel/ reservoir, connecting with S.
Manor Lane and crossing S. Harlan Circle at grade.
Water Quality/Detention. The opportunity for water quality treatment in Reach 6 is within the Clairefield
Reservoir which already serves as detention. A major storm drain tributary inflow crosses under Jewell
Avenue to discharge down a grouted boulder rundown into Clairefield Reservoir. The future ballfields area in
Wilson Family Park could potentially be graded lower to be within the floodplain and provide some additional
peak shaving detention opportunities in a major event.
Reach 6 extends approximately 3,500 feet upstream of
Sheridan Boulevard through open space and a series of
three ponds to S. Harlan Drive where it re-enters a narrow,
constructed drainageway. The Bit-O-Sea Reservoir is
privately owned and has no public or maintenance access.
Upstream of Bit-O-Sea Reservoir is Clairefield Reservoir
and the Wilson Family Park, which is within the City of
Lakewood open space. This public area has a broad
floodplain and more natural channel conditions without
hardened banks or structures and little incision. There is a
gravel trail adjacent to the gulch through the open space
which serves the Wilson Family Park and Clairefield
Reservoir. The broad floodplain and ponds offer unique
opportunities in this reach.
Wilson Family Park at S. Harlan Circle. This
area has been improved and includes a
recent LOMR.
The two road crossings within this reach. The Sheridan Boulevard crossing has approximately 10-year
capacity. The Manor Lane has 100-year capacity. Drop structures exist only at the outlets of Clairefield and
Bit-O-Sea Reservoir. The Clairefield outlet drop structure is in good condition. The Bit-O-Sea outlet drop
structure is privately owned and its current condition is unknown.
Landscape and Ecology. Wilson Family Park has a large open water body in addition to a large native open
space area. The gulch is heavily lined with riparian species of willows and cottonwoods. The upland portion
of the park is non-irrigated dryland grasses consisting of grama, wheatgrass, dropseed, and fescue species.
Shrub species include Green rabbitbrush and sage species. The short distance to the confluence of North
Sanderson Gulch is heavily vegetated with riparian species of cottonwood and willows through a series of
ponds west of the east loop of S. Harlan Circle.
Invasive species (thistle, kochia, smartweed, bindweed, prickly lettuce, common mallow, barnyard grass,
Johnsongrass, pigweed, rag weed, halogeton, redstem filaree, alfalfa, Siberian elm, Chinese elm and the
occasional Russian olive and curly dock) are present along the channel as well as in the upland grass
areas.
Reach 7 – North Sanderson Gulch Confluence to Green Gables Entrance Road (Lakewood)
Reach 7 is approximately 2,000 feet in length and extends from S. Harlan Circle to the privately owned
Shwayder Pond at the Green Gables entrance road. Except for Shwayder Pond, the reach is contained in a
narrow constructed drainageway. A public trail along the gulch exists only downstream of W. Jewell Avenue
and there is little opportunity to continue it upstream because of private property ownership. The entire
reach has been stabilized and the existing channel and facilities are generally in good condition. There is
currently little need for further improvements. Road crossings consist of W. Harlan Circle, W. Jewell Avenue
and the privately owned W. Lake Drive gated community entrance. All three of these crossings have 100-
year capacity. Three grouted rock drop structures exist in the reach, all of which are relatively new and in
good condition. The reach also contains the confluence with North Sanderson Gulch located between S.
Harlan Circle and W. Jewell Avenue.
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