FLOOD04244

• County: Ouray
• Stream Name: Uncompahgre River
• Basin: Gunnison
• Title: Hydrology Addendum to FIS Ouray County Unincorporated Areas
• Date: 7/3/1985
• Prepared For: Ouray County
• Prepared By: Montgomery Watson
• Floodplain - Doc Type: Floodplain Report/Masterplan

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PREFACE

This Hydrology Addendum (HA) 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 limited
engineering information to support the approximate delineations on the FEMA maps, and it
provides floodplain management information to guide local governments in the use of the maps,

The effective floodplain information for the Ouray County, Colorado, Unincorporated Areas, is the
FEMA Flood Insurance Study (FIS) dated July 3, 1985, The FIS contains both detailed and
approximate floodplain delineations but does not include any engineering information describing
the basis of approximate floodplain mapping, The initial purpose of this HA therefore, is to provide
Ouray County with limited supporting information for the approximate floodplain delineations,
This HA includes a description of available hydrologic information for major flooding sources
within the County, In addition, the HA gives the County 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 FIS meets the basic technical requirements for
designation and approval by the CWCR Without the inclusion of basic engineering information,
the approximate floodplain delineations shown on the Ouray County Flood Insurance Rate Maps
(FIRMs) cannot qualify for CWCB designation, Colorado statutes require that local governments
obtain from the CWCB the designation and approval of floodplain information for its use in
regulatory purposes, This HA provides a means of meeting that statutory objective, As new and
more detailed floodplain information becomes available, the approximate floodplain areas shown
on the FIRM panels will gradually be superseded. The CWCB will designate and approve new
information, and rescind old information as appropriate,

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