FLOOD10503 ‎(2)‎

• County: Clear Creek
• Basin: South Platte
• Title: Clear Creek County Hydrologic Analysis Document Correspondence
• Date: 2/1/1998
• Floodplain - Doc Type: Educational/Technical/Reference Information

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I. INTRODUCTION

Purpose
The purpose of this report is to present the methodology and results of the hydrologic analyses
for the upper Clear Creek drainage basin in Clear Creek County, Colorado. Study results include
computed peak discharges for the 2-, 5-, 10-, 50-, 100-, and 500-year flood frequencies for
selected locations on Clear Creek, South Clear Creek, West Fork Clear Creek, Chicago Creek,
and the Fall River.

Authority
According to Section 37-60-106(1)( c) of the Colorado Revised Statutes, the Colorado Water
Conservation Board has the power and duty:

... "to devise and formulate methods, means, and plans for bringing about the greater
utilization of the waters of the state and the prevention of flood damages therefrom, and to
designate and approve storm or floodwater runoff channels or basins, and to make such
designations available to legislative bodies of cities and incorporated towns, to county
planning commissions, and to boards of adjustment of cities, incorporated towns, and
counties of this state"....

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Acknowlede:ments
This report and the analyses described herein are reVlSlons to the "Engineering Division
Technical Report, Hydrologic Analysis, Type 15 Flood Insurance Study, Clear Creek County,
Colorado, Final Report" dated September 1990 as prepared by the U.S. Army Corps of
Engineers, Omaha District. The background information contained in the Corps report was
utilized for this report. Hydrologic information and peak flow values contained in the 1990
Corps report for Clear Creek from Lawson downstream, Mill Creek, and Soda Creek have not
been superseded by this study.

II. BACKGROUND INFORMATION

Basin Description
The study area includes the uppermost portion of the Clear Creek basin from the Continental
Divide to the gaging station located near Lawson, Colorado. Clear Creek flows east from the
Divide through Silver Plume, Georgetown, and Lawson. The Creek continues to flow in an
easterly direction through Idaho Springs, Golden, and the Denver Metropolitan area where it
empties into the South Platte River. The drainage area above Lawson covers approximately 145
square miles. Overland slopes vary from 10 percent in the lower basin to over 80 percent in the
high elevation mountainous regions of the upper basin. The four major tributaries to the Clear
Creek study area are South Clear Creek, West Fork Clear Creek, Fall River, and Chicago Creek.
Clear Creek channel slopes vary from 0.21 ft/ft in the upper basin, to about 0.016 ft/ft near
Lawson. Figure 1 presents a basin map for upper Clear Creek that was prepared by the Corps.

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