FLOOD04120

• Designation Number: 378
• County: Boulder
• Community: Louisville
• Stream Name: Local Drainage
• Basin: South Platte
• Title: Floodplain Information Report - Louisville, Colorado
• Date: 8/1/1994
• Designation Date: 9/1/1994
• Floodplain - Doc Type: Floodplain Report/Masterplan

I
I
I
I

CITY OF LOUISVILLE, COLORADO

FLOOD INSURANCE STUDY

Authority for the Study

I

This Type 15 Flood Insurance Study was performed for and financed by
the Federal Insurance Administration, U. S. Department of Housing and
Urban Development, by the Soil Conservation Service of the U, S. Depart-
ment of Agriculture, in accordance with Project Order No, 16, effective
~ 1, 1972, under HUD-SCS Agreement IAA-H-16-72 signed July 21, 1971.
~
The purpose of the Study is to provide maps showing the special flood
hazard areas for use by the Federal Insurance Administration in determining
where flood insurance is to be made available and in setting the premium
rates in accordance with the National Flood Insurance Act of 1968. Flood
insurance study guidelines prepared by the Soil Conservation Service were
followed,

I

I
I
I

Technical Studies

a.

Description of Study Area

I
II
I I

The area of study is the City of Louisville located in the southeast
corner of Boulder County, Colorado. The study area is confined within
the corporate limits of Louisville which receives runoff from three
small drainages originating about 1 1/2 miles west of the city. The
southeast corner of Louisville is within the flood plain of Coal Creek;
however, the streambed of Coal Creek lies about 1/4 mile south of the
city limits. The northern most drainage is the Goodhue Ditch. The
other two drainages are unnamed and for this study have been designated
as Center Tributary and West Tributary.

I

The small drainages are tributaries to Coal Creek and drain a total
area of little over one square mile. Starting at elevation 5,620
feet mean sea level, the watershed slopes in an easterly direction
to about elevation 5,400 feet near the western edge of Louisville.

I
I
I
I
I I
II

Coal Creek originates on the east slope of the Continental Divide or
Front Mountain Range, and flows generally east to become a tributary
to Boulder Creek, a major drainage of the South Platte River. The
drainage area of Coal Creek above Louisville is about 36 square miles.
Upper reaches of the watershed begin at 10,500 feet mean sea level
elevation and the flood plain elevation near the southeastern edge
of the city limits is 5,330 feet.