FLOOD10349 ‎(3)‎

• County: Adams
• Community: Adams County
• Stream Name: Little Dry Creek, Clear Creek
• Title: LOMR - Affected Panels 08001C0309 G, 0320 G - Case No. 02-08-250P
• Date: 9/29/2004
• Prepared For: Adams County
• Prepared By: FEMA
• Floodplain - Doc Type: Historic FEMA Regulatory Floodplain Information

Federal Emergency Management Agency
Washington, D.C. 20472

JUN 14 2004

CERTIFIED MAIL
RETURN RECEIPT REQUESTED

IN REPLY REFER TO:
Case No.: 02-08-250P

The Honorable Elaine T. Valente
Chairman, Adams County
Board of Commissioners
450 South Fourth Avenue
Brighton, CO 8060 I

Community: Adams County, CO
Community No.: 080001
Panels Affected: 0800lC0309 G and 0320 G
Effective Date of S EP . 2 9 2M1.
This Revision: UU"t

I 02-I-A-C

Dear Ms. Valente:

This responds to a request that the Department of Homeland Security's Federal Emergency Management
Agency (FEMA) revise the effective Flood Insurance Rate Map (FIRM) and Flood ,Insurance Study (FIS)
report for Adams County, Colorado and Incorporated Areas, in accordance with Part 65 of the National
Flood Insurance Program (NFIP) regulations. In a request dated March 13, 2002, 1
~.E., Vice President, Sellards & Grigg, Inc., requested that FEMA revise the FIRM and FIS
report to show the effects of construction of the Little Dry Creek railroad culverts and 64th Avenue culvert
project along Little Dry Creek from West 64th Avenue to just upstream of Federal Boulevard (U.S.
Highway 287). The project included construction of three culverts, realignment of Little Dry Creek,
channelization from West 64th Avenue to Federal Boulevard, and construction of a low-flow channel in
the left overbank area from approximately 100 feet upstream of the Colorado and Southern Railroad
(C&SRR) to West 64th Avenue. As a result of the modifications, the Speci?l Flood Hazard Area (SFHA),
the area that would be inundated by the flood having a I-percent chance of being equaled or exceeded in
any given year (base flood), along Clear Creek near West 64th Avenue also was affected.

All data required to complete our review of this request were submitted with letters from
, P .E., Project Manager, also with Sellards & Grigg, Inc., and - Jf

J

We have completed our review of the submitted data and the flood data shown on the effective FIRM and
in the effective FIS report. We have revised the FIRM and FIS report to modify the elevations, floodplain
and floodway boundary delineations, and zone designations of the base flood along Little Dry Creek from
the confluence with Clear Creek to Federal Boulevard. We also have modified the SFHA along Clear
Creek in the left overbank area from Pecos Street to just downstream of the C&SRR. As a result of the
modifications, for Little Dry Creek, the Base Flood Elevations (BFEs) and the widths of the SFHA and
regulatory floodway increased in some areas and decreased in other areas, and the width of the SFHA for
Clear Creek decreased. The SFHA along the above-mentioned low-flow channel was designated Zone A,
with no BFEs determined. The mod!fications are shown on the enclosed annotated copies of FIRM