FLOOD05544

• County: Arapahoe
• Community: Arapahoe County
• Stream Name: Cottonwood Creek
• Basin: South Platte
• Title: LOMR - Affected Panel 08005C 0480 J - Case No. 95-08-223P
• Date: 1/16/1996
• Prepared For: Arapahoe County
• Prepared By: FEMA
• Floodplain - Doc Type: Historic FEMA Regulatory Floodplain Information

I

Federal Emergency Management Agency
Washington, D.C. 20472

CERTIFIED MAIL
RETURN RECEIPT REQUESTED

IN REPLY REFER TO:
Case No,: 95-08-223P

Mr. Thomas R. Eggert
Chairperson, Arapahoe County
Board of Commissioners
5334 South Prince Street
Littleton, Colorado 80166

Community: Arapahoe County, Colorado
Community No.: 080011
Panel Affected: 08005C0480 J
Effective Date of
This Revision: J A N 16 1996

102-I-A-C

Dear Mr. Eggert:

This is in response to a request for a revision to the effective Flood Insurance Study (FIS) and National
Flood Insurance Program (NFIP) map for your community, Specifically, this responds to a letter dated
July 7,1995, from Mr. Michael S, Dungan, P.E., Project Manager, Muller Engineering Company, Inc, ,
regarding the effective FIS report and Flood Insurance Rate Map (FIRM) for Arapahoe County, Colorado
and Incorporated Areas. Mr. Dungan requested that the Federal Emergency Management Agency
(FEMA) revise the effective FIRM to show the effects of updated topographic data and the construction
of a detention pond upstream of East Easter Road, a triple-box culvert at East Briarwood Avenue, and
channel modifications, including drop structures and bank stabilization, associated with roadway
improvements to East Easter Avenue, South Lima Street, and East Briarwood Avenue. The revised data
affect the reach along Cottonwood Creek from just downstream of East Arapahoe Road to just
downstream of Inverness Drive East.

All data required to complete our review of this request were submitted with letters dated July 7 and
October 18, 1995, from Mr. Dungan, and a letter dated October 6, 1995, from Ms. Laurie Tatlock,
Inverness Water and Sanitation District. All fees necessary to process this Letter of Map Revision
(LOMR), a total of $2,970, have been received.

We have completed our review of the submitted data and the flood data shown on the effective FIRM and
have revised the FIRM to modify the elevations and floodplain and floodway boundary delineations of a
flood having a I-percent chance of being equaled or exceeded in any given year (base flood) along
Cottonwood Creek from just downstream of East ATapahoe Road to just downstream of Inverness Drive
East.

The project results in increases and decreases in base flood elevations (BFEs) along this reach of
Cottonwood Creek. BFEs increased from just downstream of East Briarwood A venue to approximately
1,700 feet upstream of East Easter Avenue. The maximum increase in BFE, 10.4 feet, occurs just
upstream of East Easter A venue. The BFEs decreased from just downstream of East Arapahoe Road to
just downstream of East Briarwood Avenue, and from approximately 1,700 feet upstream of East Easter
Avenue to just downstream of Inverness Drive East. The maximum decrease in BFE, 5.6 feet, occurs
approximately 160 feet downstream of Inverness Drive East. The Special Flood Hazard Area (SFHA)
and floodway boundary delineations generally shifted approximately 100 feet west of those shown on the
effective FIRM. The width of the SFHA increased along the entire revised reach of Cottonwood Creek,
The maximum increase in SFHA width, 220 feet, occurs approximately 300 feet upstream of East