FLOOD09354

• County: Douglas
• Community: Douglas County
• Basin: South Platte
• Title: South Platte River Post Wildfire Floodplain Study, Hayman Burn Area, Douglas County
• Date: 11/24/2004
• Prepared For: CWCB and Douglas County Public Works
• Prepared By: Anderson Consulting Engineers
• 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

floodplain along the South Platte River near Deckers. located within the current study area. The
hydraulic model prepared for the flood insurance study (FIS) was used as the basis for the
hydraulic model prepared and used by USGS as pan of their post-fire hydrologic hazards study.

1.3 Purpose and Scope of the Current Study

The purpose of the current study is to prepare IOO-year floodplain and I-foOl rise
tlood\....ay mapping for 16 miles of the South Platte River in southwest Douglas County. using
post-wildfire hydrology developed by the U.S. Geological Survey. The scope of the study
includes the definition of discharge profiles for the ri\"er through the majority of the study area
based on information provided by the USGS. Also included is a basic hydrologic evaluation of
the ri\'er at the confluence with the North Fork South Plane River in order to define IOO-year
discharges downstream of the Hayman Burn area. beyond the portion of the South Platte Basin
that was studied by the USGS. The primary focus of this study is the detailed hydraulic analysis
of the South Platte River for the IOO~year flood event and the definition of a I-foot rise
floodway. along v.;th the delineation of both the 1 DO-year floodplain and I-foot floodway. In
addition. this study is tasked with the preparation of flood way data tables and graphical flood
profiles in FEMA Flood Insurance Study fonnat. intended for inclusion \,,'ith the Douglas County
Digital Flood Insurance Rate Map that is in the process of being reviewed and adopted.

COCWCBOJ_South Plane_report doc

J

A,dmso, Co\SlhhG bGi'H1ts, he.