FLOOD03791

• County: Denver
• Community: Cherry Vale
• Stream Name: Little Dry Creek
• Basin: South Platte
• Title: Cherry Vale Meadows Drainage Study
• Date: 5/1/1982
• Prepared For: Arapahoe
• Prepared By: Miller-Ernstein
• Floodplain - Doc Type: Floodplain Report/Masterplan

"." MILLER - ERNSTSEN
AND ASSOC., INC.

CIVIL AND LAND DEVhoPMENT ENGINEERING
LAND SURVEYING

7.'0 EAST PRENTICE AVE. #~02

770-201 IS

E~GL.EWOOO. eOL.ORACO 801 f t

CHERRY VALE MEADOWS

DRAINAGE STUDY

May, 1982
Revised October 19, 1982

INTRODUCTION

Cherry Vale Meadows is a proposed 8 lot, single-family residential subdivision
of a 7.64 aCre tract in Cherry Hills Village, Colorado. The land is presently
undeveloped and is zoned for 1/2 acre sites. Cherry Vale Acres East Suvdivision
lies to the south and west and Cherry Vale Acres Filing No.4 lies to the north.
The land to the east is undeveloped and unplatted. Little Dry Creek flows
between the site and the two adjoining subdivisions on the south, west and north.
Part of the site is within the 100 year flood plain of the creek.

Cherry Vale Drive comes to a dead end at Little Dry Creek, and is the only
dedicated public access to the property. An attempt to obtain an access from
the owner of the undeveloped property to the east was unsuccessful. Therefore,
a bridge will have to be constructed across the creek from the north 'into the
site.

CRITERIA

The major drainage concern for this project is the 100 year flood plain which was
determined in a study prepared for the Urban Drainage and Flood Control District
by McCall, Ellingson and Morrill, Inc. dated February, 1974, entitled "Major
Drainageway Planning, Little Dry Creek". A computer program entitled "HEC-2"
(written by the U. S. Army Corps of Engineers) was used in analyzing the
existing and proposed channel conditions, and is the same program that was used
in the McCall, Ellingson and Morrill, Inc. study.

Criteria for design of the proposed bridge and channel improvements are as
follows:

1. The flood plain elevation may not be raised as a result of the proposed
improvements.
2. The on-stream storage capacity of the natural flood plain may not be reduced.
3. Velocities in the stream must not be increased to erosive velocities.
4. Minimize changes to the natural appearance of the flood plain.

DISCUSSION

The existing 100 year flood plain as shown in the Little Dry Creek study was
first calculated using the HEC-2 program, with a 100 year flow of 3000 c.f.s. and