FLOOD08560

• Designation Number: 228
• County: Denver
• Community: Denver
• Stream Name: Westerly Creek
• Basin: South Platte
• Title: Flood Hazard Area Delineation - Westerly Creek
• Date: 3/1/1983
• Designation Date: 1/1/1984
• Floodplain - Doc Type: Floodplain Report/Masterplan

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SCOPE

PREFACE

PURPOSE

The original scope of work for this project included the following items:
1) Develop water surface profiles for the 10 and 100-year flood discharges, a
flood outline for the 100-year floodplain and the limits of the floodway
based upon an equal degree of encroachment which results in an increase of
the 100-year water surface of one foot or less at any point.
a) The Urban Drainage and Flood Control District was to provide 1"-100'
mapping with a 2' contour interval as well as all hydrology and the
hydraulic analysis for the discharge from the west embankment of
Kelly Road Dam.
b) The remainder of the hydraulic analysis was to be performed by
Merrick & Company.
2) Depict the limits of the 100-year floodplain, profiles of the channel bottom
,

INTRODUCTION

Merrick & Company, in November, 1981, was contracted by the Urban Drainage
and Flood Control District, under its work program for 1981 (Resolution No. 58,
Series of 1980) and its previously expressed intent to assist public bodies which
have heretofore enacted floodplain zoning measures (Resolution No. 14, Series of
1970), to update the existing "Flood Hazard Area Delineation, Westerly Creek"
prepared by Camp Dresser and McKee, Inc. and dated January,1977, between
Station 66+00 and Station 163+50.

The primary objective of this study was to delineate the after-construction 100-
year floodplain of Westerly Creek so that Denver and Aurora can implement
floodplain regulations and other land use controls, as needed, to reduce potential
flood damages and unwise development in the floodplain. Other objectives of this
study were to develop a 10-year water surface profile and a floodway for use by
the Federal Emergency Management Agency (FEMA) in its Flood Insurance Rate
Maps of Denver and Aurora.

This study presents the revised floodplain, flood way and flood profiles
incorporating improvements constructed or under construction between Stapleton
International Airport (SIA) and 11th Avenue.

the 10 and 100-year water surfaces, typical cross-sections and locations and
100-year flows and velocities at appropriate locations on the mapping
provided.
3) Prepare a report which contains:
a) Summary of pertinent data.
b) Identification of major basin features.

c) Discharge profiles, typical hydrographs and hydrologic information (all
of which was to be provided by District).
d) Summary of hydraulic data.
e) Index Map (to be provided by District).
f) Tabulation of flood hazard information.