FLOOD08560

• Designation Number: 228
• County: Denver
• Community: Denver
• Stream Name: Westerly Creek
• Basin: South Platte
• Title: Flood Hazard Area Delineation - Westerly Creek
• Date: 3/1/1983
• Designation Date: 1/1/1984
• Floodplain - Doc Type: Floodplain Report/Masterplan

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The contract was amended in January, 1982 because sufficient hydrology
reflecting current conditions was not readily available. Merrick &: Company,
under this amendment, was authorized to determine the 100-year hydrology for
the drainage area downstream of Kelly Road Dam, combine this with the 100-year
discharge hydrograph from Kelly Road Dam provided by the Urban Drainage and
Flood Control District and route the hydrographs to arrive at the current 100-year
discharges for the study area.

December, 1971: "Reconnaissance Investigation, Westerly Creek, Colorado"
(Omaha District, Corps of Engineers).
The report found that a potential project consisting of detention storage above the
Highline Canal and channel improvement from East Alameda Avenue to the
confluence of Westerly Creek with Sand Creek would economically relieve
existing and potential flood problems in the drainage basin. The report
recommendations were not implemented.

SUMMARY OF EXISTING INFORMATION

Several previous studies have been undertaken to determine the extent of flooding
problems in the Westerly Creek basin. Camp Dresser and McKee, Inc., in their
"Flood Hazard Area Delineation, Westerly Creek" dated January, 1977,
summarized the previous reports as follows:

April, 1973: "Master Drainage Plan, Aurora, Colorado" (Nelson, Haley, Patterson
&: Quirk, Inc.).

January, 1952: "Survey Report on Flood Control for the City of Aurora, Colorado"
(Omaha District, Corps of Engineers).
The report recognized a flOOd problem on Westerly Creek between Lowry Air
Force Base (AFB) and Sand Creek. The construction of the Kelly Road Dam and
detention pond was recommended to alleviate the run-off from the large paved
areas of the AFB. As a result of this report, construction of Kelly Road Dam was
completed in November, 1953.

Proposed flood water conveyance and detention facilities for the City of Aurora
are described in detail in this report. However, the problems associated with
conveying storm water from the area south of the AFB to the lower drainage basin,
and the inadequacy of drainage capacity in the lower basin, were not resolved.

June, 1973: "Analysis Concerning Import of Storm Sewer Proposals by City of
Aurora on Drainage Within Boundaries of Lowry Air Force Base" (Omaha District,
Corps of Engineers).

November, 1971: "Adequacy Report, Kelly Road Detention Dam" (Omaha
District, Corps of Engineers).

The report concluded that by 1985 urban development upstream of Kelly Road will

have lowered the protection level of the detention structure to a 10-year
frequency.

Two proposals for storm sewer construction by Aurora affecting drainage
conditions on Lowry Air Force Base were reviewed. One proposal for the
diversion of a drainage area into the AFB was not acceptable because of the
imposition of a demand on the Kelly Road Dam storage capacity which it is not
designed to handle. The other proposal for construction of storm drains within the
area contiguous to the AFB is viewed negatively; however, it is recognized that
there is no authority to prevent the drain systems from being constructed.

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