FLOOD06828

• Designation Number: 177
• County: Jefferson
• Community: Unincorporated Jefferson County
• Stream Name: Weaver Creek
• Basin: South Platte
• Title: Flood Hazard Area Delineation - Weaver Creek
• Date: 5/1/1981
• Designation Date: 9/1/1981
• Floodplain - Doc Type: Floodplain Report/Masterplan

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-11-

-12-

In the reach of Weaver Creek from West Quincy Avenue to the
confluence with Bear Creek, land use within the flood hazard
area is primarily open space and agricultural. The flood
hazard area is, generally, contained within a well-defined
channel. It averages 340 feet in width, channel velocities
average 6.5 feet per second (fps) and overbank velocities
where they exist average 2.9 fps. The lOa-year flood profile
overtops four small dams and U.S. Highway 285. Near the
Warrior Canal crossing of Weaver Creek, a number of
residential homes are included within the flood hazard area.

reservoirs were damaged severely during a flood in 1973.
Although the lOa-year flood hazard area, and the various
flood profiles are computed assuming the dam embankments
remain in place, their structural stability is suspect during
the lOa-year flood event.

The lOa-year flood plain of Weaver Creek meets the lOa-year
flood plain of Bear Creek, as shown on Sheet 13.

Immediately below West Quincy Avenue, the flood hazard area
is divided for a short reach. Overtopping of the Warrior
Canal causes a backwater which extends into the Mount Carbon
Estates subdivision, as shown on Sheets 11 and 12. Areas
below the Warrior Canal could be subject to shallDw overland
flooding from overtopping of the canal. Upstream of U.S.
Highway 285, a considerable amount of fill material was being
placed near the entrance to the culvert under the highway, at
the time of the mapping. Additional material was placed
during the course of the study. The fill material is
considered unstable, and the capacity of the culvert under
the highway could be adversely affected by this material
during a significant flow.

U.S. Highway 285 causes flood waters to back up on the
upstream side. A small portion of the lOa-year flood escapes
to the east, creating an area of shallow overland flooding.
The lOa-year flood overtops the highway embankment, and some
flow could escape to the east along the median strips, as
shown on Sheet 12.

Below U. S. Highway 285, the lOa-year flood overtops three
small reservoirs. The overflow structures for the first two

~ Leonard Rice Consulting Water Engineers, Inc.

~ Leonard Rice Consulting Water Engineers,lnc.