FLOOD02896

• County: Douglas
• County: Arapahoe
• Community: Douglas County, Arapahoe County
• Stream Name: Happy Canyon Creek, Badger, Newlin, Baldwin, Sulph
• Basin: South Platte
• Title: Flood Hazard Area Delineation - Happy Canyon Creek, Badger, Newlin, Baldwin, Sulpher and Tallman Gulch
• Date: 11/1/1977
• Prepared For: Douglas County / Arapahoe County
• Prepared By: UDFCD
• Floodplain - Doc Type: Floodplain Report/Masterplan

I

I

I

I

I

I

I

I

I

I

I

I

I

I

I

I

I

I

I

PREFACE

Authorization

future, developed conditions in the basin as determined from current

master planning maps. Possible future improvements to control floods

are not a consideration of this report.

This report was authorized by the Urban Drainage and Flood Control District

in joint sponsorship with the Colorado Water Conservation Board.

The District has the power to enact District-wide flood plain regulations.

At present, however, the District provides flood plain information and

mapping for local agencies to adopt and administer their own flood plain

regulations, with the assistance of the District.

The information in this report does not imply any state action to zone or

regulate use of flood plains. The District has the authority to regulate

flood plains, but to date has chosen to leave flood plain regulation

responsibility with local governments. The report provides a suitable

basis for the adoption of land use controls to guide flood plain management,

thereby decreasing the potential for flood losses.

Upon acceptance of this report by the Urban Drainage and Flood Control

District and approval by the Colorado Water Conservation Board, the areas

described as being inundated by the lOO-year flood (Intermediate Regional

Flood) can be designated as flood hazard areas and their use regulated

accordingly. The terms "Intermediate Regional Flood", "lOO-Year Flood",

and "One Percent Flood" can be used interchangeably since they all rep-

resent the same flood event.

Flood water surface elevations and flood plain boundaries are often revised

by road and bridge construction, flood plain development, flood control

improvements, or natural processes. Prior to utilization of this report

for planning or design purposes, the user is advised to contact the

Urban Drainage and Flood Control District or the Colorado Water Conservation

Board to determine if the information in this report has been amended.

Purpose and Scope

Acknowledgements

This report was prepared for the guidance of local officials in planning

the use and regulation of the flood plain. The report includes information

on past floods and the nature and extent of probable future floods which

can be reasonably expected on the respective study Teaches. The lOO-year

flood should be given appropriate consideration before planning for

development in the flood plain.

This report was prepared by Howard Needles Tammen & Bergendoff, Lakewood,

Colorado, at the request of the Urban Drainage and Flood Control District.

A concurrent study was made of much of the project area by HNTB for the

U.S. Department of Housing and Urban Development, Federal Insurance

Administration. Engineering data generated from the HUD-FIA study was

used in preparation of this report.

The lOO-year flood plain is shown on the Flood Hazard Area Delineation Maps

which delineate the areas that would be inundated by such a storm. Flood

profiles show the water depths relative to the stream bed and elevation

reference data is given that can be applied across the full width of the

stream valley. Valley cross sections are presented to indicate ground

level across the valley at specified locations and the overlying flood

depths. The flood profiles and flooded area data presented are based on

Survey control data and topographic mapping was provided by M & I, Inc.,
Fort Collins, Colorado.