FLOOD00584

• County: Boulder
• County: Weld
• Community: Erie
• Stream Name: Coal Creek
• Title: Hydraulic Analysis and Floodplain Revision for Coal Creek Flood Control Project
• Date: 9/1/1993
• Prepared For: Erie
• Prepared By: WRC Engineering, Inc.
• Floodplain - Doc Type: Project

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I. INTRODUCTION

This report presents the results of a Hydraulic Analysis and Floodplain Revision for the Coal Creek
Flood Control Project. Coal Creek is located in several counties beginning in the mountains northwest of
Denver. The proposed improvements are located in Weld County about rwo miles south of the confluence
with Boulder Creek, The Coal Creek basin drains about 79 square miles, The Coal Creek drainageway
improvements will be located in Sections 18 and 19, Township I North, Range 68 West of the 6th Principal
Meridian (see Figure-I), The 4,500 foot length of the drainageway improvements begin upstream of Briggs
Street and continue south to just upstream of Perry Street (Weld County Road 8),

II. PURPOSE AND SCOPE OF SERVICES

The purpose of this report is to prepare the required hydraulic calculations. drawings, and
documentation for submittal to the Federal Emergency Management Agency (FEMA). This repon is pan of
the application for a Conditional Letter of Map Revision (CLOMR) for the Coal Creek Flood Control Project.

The Town of Eric (Town) and WRC Engineering, Inc (WRC) entered an agreement on May 8,1991.

for preparation of documentation for the Coal Creek Flood Control Project CLOMR submittal to FEMA, This

repon contains peninent documentation for the CLOMR application, The Town of Erie is responsible for

preparing the actual application and submittal of the repon to FEMA,

III. EFFECTIVE FLOODPLAIN AND FIRM

The current effective floodplain delineation is based on the current effective Flood Insurance Rate

Maps (FIRM) and is presented on Firm panel No, 080181-000ID, effective date September 28. 1990, and

Panel No, 080266-09600, effective date September 28, 1990, (see Figure-3),

The original study for this basin was the Flood Hazard Analysis for Coal Creek and Rock Creek

prepared by O,S, Depanment of Agriculture and Soil Conservation Service in October, 1976. The Town of

Erie authorized a repon, "Floodplain Infonnation, Flood Control and Floodplain Management" prepared by

Water Resources Consultants. Inc, in August, 1980, to review the floodplain through the Town and make

recommendations for corrective action, In September, 1982, FEMA completed a Flood Insurance Study