FLOOD09020

• County: Denver
• Community: Denver
• Stream Name: Goldsmith Gulch
• Basin: South Platte
• Title: LOMR - Affected Panel 080046 0019 D, 0020 D, 0024 D, 0025 D - Case No. 97-08-009P
• Date: 1/8/1997
• Prepared For: Denver
• Prepared By: FEMA
• Floodplain - Doc Type: Historic FEMA Regulatory Floodplain Information

-I

Federal Emergency Management Agency
Washington, D.C. 20472 R
ECEIVED

JAN 24 1997

"
,

CERTIFIED MAIL
RETURN RECEIPT REQUESTED

IN REPLY REFER TO:
Case No.: 97-08-009P

Colorado Water
Conservation Board

The Honorable Wellington Webb
Mayor, City and County of Denver
1437 Bannock Street
Denver, Colorado 80202

Community: City and County of Denver,
Colorado
Community No.: 080046
Panels Affected: 0019 D, 0020 D, 0024 D,
and 0025 D
Effective Date of
This Revision: J AN 0 8 1997

102-I-A-C

Dear Mayor Webb:

This responds to a request that the Federal Emergency Management Agency (FEMA) revise the effective
Flood Insurance Rate Map (FIRM) and Flood Insurance Study (FI S) report for your community in accordance
with Part 65 of the National Flood Insurance Program (NFIP) regulations, In a letter dated September 20,
1996, Mr. Nick Skifalides, P.E., Deputy Manager of Public Works, City and County of Denver, requested
that FEMA revise the FIRM and FIS report to show the effects of the construction of Phase III of the
Goldsmith Gulch Flood Control Project along Goldsmith Gulch, Phase III of this project includes construction
of the Florida-South Monaco Street Parkway Storm Sewer System, channel and culvert construction and
improvements, construction of an earthen berm at Bible Park, and construction of a detention pond at the
comer of Iliff Avenue and South Monaco Street Parkway, The improvements affect the reach of Goldsmith
Gulch from its confluence with Cherry Creek to just upstream of Belleview Avenue.

The construction of the Goldsmith Gulch Flood Control Project has created two distinct flow paths for
Goldsmith Gulch downstream of Iliff Avenue: overland and street flow along South Monaco Street Parkway
and flow contained within the channels and culverts of the existing Goldsmith Gulch flow path, The overland
and street flow down South Monaco Street Parkway has been renamed the South Monaco Street Parkway
Overflow.

As part of this revision request, the hydrologic analyses along Goldsmith Gulch were revised to account for
the construction of the detention pond and improvements to existing detention facilities. The revised
hydrologic analyses along Goldsmith Gulch also affect the flood discharges for Cherry Creek downstream of
the confluence of Goldsmith Gulch, The flow from Goldsmith Gulch represents a large portion of the total
flow in Cherry Creek downstream of the confluence, affecting the discharges and elevations of the flood
having a I-percent chance of being equaled or exceeded in any given year (base flood) along Cherry Creek
from the confluence of Goldsmith Gulch to Cherry Creek's confluence with the Platte River. Revisions to the
discharges and base flood elevations (BFEs) along this entire reach of Cherry Creek are beyond the scope of
this revision. However, we evaluated the effects of the revised base flood discharge on the reach of Cherry
Creek from approximately 50 feet upstream of South Holly Street to approximately I, 900 feet upstream of
South Monaco Street Parkway to determine the impact of the revised discharge on backwater flooding from
Cherry Creek in the vicinity of Minnesota Drive, This request follows up on a Conditional Letter of Map
Revision issued on June 22, 1995.