FLOOD00875

• County: Grand
• Community: Granby
• Title: Floodplain Information Report - Town of Granby
• Date: 3/1/2002
• Prepared For: Granby
• Prepared By: CWCB
• Floodplain - Doc Type: Floodplain Report/Masterplan

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PREFACE

This Floodplain Information Report (FIR) is part of a program by the Colorado Water Conservation
Board (CWCB) to make approximate floodplain maps prepared by the Federal Emergency
Management Agency (FEMA) easier for local governments to use. This CWCB report provides
up-to-date information to replace the approximate floodplain delineations on existing FEMA maps,
and it provides floodplain management information to guide the local governments in the use of the
maps.

The official FEMA floodplain information for the Town of Granby is the Flood Hazard Boundary
Map (FHBM), dated August 15, 1975. The FHBM was prepared by FEMA and contains
approximate floodplain delineations for three flooding sources within the Town's boundaries as
they existed at the time of the study. The approximate floodplain mapping does not include any
engineering information to describe basis of the mapping. In addition, the floodplains shown on the
FHBM do not reflect current development within the Town. The initial purpose of this report is to
provide the Town with modified flood area mapping and limited supporting information to replace
those floodplain delineations in the FEMA study. In addition to the FEMA study, which considers
only those areas north of Highway 40, this FIR verifies the current Fraser River and Tenmile Creek
floodplain designation as shown in the 1987 study entitled "Flood Hazard Identification Report,
Fraser River and Tenmile Creek, Granby, Colorado," which lie south of Highway 40. This FIR
includes a description of available hydrologic information for major flooding sources within and
adjacent to the Town and for CWCB designation purposes, supercedes the FHBM. In addition, the
FIR gives the Town some basic information about floodplain management and provides some
alternatives that could be considered in formulating and implementing floodplain management
objectives.

A second function of this report is to assure that the floodplain information meets the basic
technical requirements for designation and approval by the CWCB. The inclusion of basic
engineering information allows the approximate floodplain delineations within this report to qualify
for CWCB designation. Colorado statutes require that local governments obtain from the CWCB
the designation and approval of floodplairi informa:tion for their uSe in regulatory purposes. This
FIR provides a means for the FHBM to meet that statutory objective. As new and more detailed
floodplain information becomes available, the approximate floodplain areas shown in this report
will become superseded. The CWCB will designate and approve new information, and rescind old
information as appropriate.

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