FLOOD06839

• County: Pueblo
• Community: Pueblo
• Stream Name: Fountain Creek
• Basin: Arkansas
• Title: Fountain Creek CLOMR
• Date: 3/5/1998
• Prepared For: Pueblo County
• Prepared By: CWCB
• Floodplain - Doc Type: Community File

,;

~
...

Colorado Water Conservation Board
Department of Natural Resources
721 Centennial Building
1 313 Sherman Street
Denver, Colorado 80203
Phone: [phone]
fAX: [phone]

STATE OF COLORJ\DO

o

Roy Romer
Governor

James S. LochheCld
Executive Direcror, DNR

DtlriesC. lite, P.E.
Director, ewes

March 5,1998

Mr. Dennis Maroney
Bureau of Public Works, Engineering Division
City of Pueblo
211 East D Street
Pueblo, CO 81003

Dear Dennis:

I am writing you concerning the submittal for a Conditional Letter of Map Revision
(CLOMR) for Fountain Creek in the vicinity of the proposed interchange project for
Interstate Highway 25, U.S. Highway 50, and State Highway 47 in Pueblo. We received
a packet concerning this project at a meeting with the project engineer, CH2M HILL on
February 4,1998.

The project involves the revision of FIRM panels #3 and #6 from the City of Pueblo's
1986 Flood Insurance Study (FIS). The revisions being requested would alter the
floodplain delineation and part of the floodway delineation for Fountain Creek from a
point approximately 700 feet downstream of the crossing of U.S. Highway 50 upstream
to a point approximately 2800 feet upstream of the crossing of State Highway 47. The
changes would affect a total stream length of approximately 8000 feet.

Before analyzing the changes to the flood elevations that could be directly attributed to
the highway project, the engineer prepared a hydraulic analysis of 1997 pre-project
conditions (referred to as the "Corrected Effective" analysis). That analysis showed
substantially different flood elevations from the elevations contained in the 1986 FIS.
Reasons for those differences will be discussed later in this letter. The engineer then
determined the effect of the proposed highway project, when compared to the 1997 pre-
proiect analvsis. The highway project was found to have relatively minor effects on flood
elevations and floodplain boundaries.

Back!!round
The 125 Interchange project is a traffic capacity and traffic safety project. The specific
components of the project that would have an impact on the currently mapped floodplain
of Fountain Creek are: 1) the widening (not lengthening) of the State Highway 47 bridge