FLOOD05530

• County: Larimer
• Community: Loveland
• Stream Name: Big Thompson River
• Basin: South Platte
• Title: CLOMR - Case 96-08-363R
• Date: 12/9/1996
• Prepared For: Loveland
• Prepared By: FEMA
• Floodplain - Doc Type: Historic FEMA Regulatory Floodplain Information

Federal Emergency Management Agency
Washington, D.C. 20472

DEC091996

Fl12CI2IVED
DEe 12 1996

CO/ora'
Consef\la~o Water
On eo",cJ
Community: City of Loveland, Colorado
Community No.: 080103

CERTIFIED MAIL
RETURN RECEIPT REQUESTED

IN REPLY REFER TO:
Case No.: 96-08-363R

The Honorable Treva Edwards
Mayor, City of Loveland
500 East Third Street
Loveland, Colorado 80537

104

Dear Mayor F..dwards:

This responds to a request that the Federal Emergency Management Agency (FEMA) comment on the
effects that a proposed project would have on the effective Flood Insurance Rate Map (FIRM), Flood
Boundary and Floodway Map (FBFM), and Flood Insurance Study (FIS) report for your community in
accordance with Part 65 of the National Flood Insurance Program (NFIP) regulations. In a letter dated
August 27, 1996, Mr. David A. Guetig, P.E., Project Manager, Galloway, Romero & Associates,
requested that FEMA evaluate the effects that the proposed placement of fill just upstream of Taft Avenue
along the southern overbank of the Big Thompson River would have on the flood hazard information shown
on the effective FIRMs, FBFMs,and FIS reports for your community and the unincorporated areas of
Larimer County, Colorado. The fill will be placed in association with the proposed development of the
Alliance Group Retail Center northwest of the ,intersection of West FirstStrl:et.and Taft Avenue.

All data required to complete our review of this request for a Conditional Letter, of Map, Revision
(CLOMR) were submitted with letters from Mr. Guetig. A CLOMR was also issued on this date to reflect
the effects of Mr. Guetig's revision request on the FIRM, FBFM, and FIS report for the unincorporated
areas of Larimer County.

In support of his request, Mr. Guetig provided a hydraulic analysis of existing conditions along the reach
of the Big Thompson River from approximately 1,350 feet downstream of West First Street to
approximately 3,800 feet upstream of Taft 4venue. The majority of the detailed flood hazard information
tor this reach is shown on the effective FIRM and }O"BFM for the unincorporated areas of Larimer County
even though a large portion of this area has been annexed by the City of Loveland. There is an apparent
mismatch between the flood hazard information shown on the effective FIRM and FBFM for the City of
Loveland and that shown on the effective FIRM and FBFM for the unincorporated areas of Larimer
County. In a letter dated April 1, 1996, we informed Mr. Guetig that the HEC-2 hydraulic computer
models developed by Resource Consultants, Inc. (RCI), used to prepare the effective FIRM and FBFM
for the City of Loveland should be used as the base conditions models for any future map revisions for the
above-referenced reach of the Big Thompson River because they provide more up-to-date information.
RCI developed a model for the main channel of the Big Thompson River and a model of the split flow
along a southern overflow path from just downstream of the West First Street bridge to just upstream of
Taft Avenue. The HEC-2 models of existing conditions that were submitted by Mr. Guetig incorpprate
more detailed topographic information and correct errors in the RCI models.

We have completed our review of the submitted data and the flood data used to prepare the effective
FIRMs and FBFMs for your community and the unincorporated areas of Larimer County, Colorado.