WSP11430

• File Number: 8449
• Description: Platte River Projects
• State: CO
• Basin: South Platte
• Date: 5/1/1975
• Author: USACOE
• Title: Needs Identification and Supplement to the Plan of Study, Water and Related Land Resources Management Study
• Water Supply Pro - Doc Type: Publication

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of the 208 technical paper, with LWCOG acting as the management

and implementation agency for the continuing planning process for

the area. This would create minimum disruption to the Corps'

planning effort and would afford maximum participation and imple-

mentation control by LWCOG.

METRO DENVER STORMWATER RUNOFF

DRCOG, as indicated in its 208 Plan of Study, intends to

evaluate the effects of urban stormwater runoff for the Denver

metro area. DRCOG presently uses a mathematical model Hydrocomp

for stormwater runoff. This model loads storm runoff on a uniform

incremental basis along the length of each stream segment. The

loading to the segment corresponds to the runoff generated by the

storm being modeled. This modeling technique flattens out the

peaks of storm runoff events because of incremental rather than

point loading from a drainage basin.

DRCOG has suggested that the Corps fUrnish stormwater runoff

information to DRCOG using EPA's stormwater runoff model. This

model has been developed for the Denver metropolitan area by the

Corps of Engineers for flood control vork. Unlike the Hydrocomp

model, the EPA model loads storm runoff at a single discharge

point to the stream much like it occurs in nature. This technique

does not reduce the peaks of storm runoff events.

Using the peak flow information fUrnished by the Corps, DRCOG
could evaluate the validity of the storm runoff function of the
Hydrocomp model. The input of the Corps' peak flow information into
the quality function of the Hydrocomp model will allow the evalua-
tion of stormflows with reduced peaks compared to those with higher
peaks on the instream water quality.

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