Planning of Outfall Systems for the Willow Creek, Little Dry Creek and Greenwood Gulch Watersheds

Planning of Outfall Systems for the Willow Creek, Little Dry Creek and Greenwood Gulch Watersheds

AREA

The Willow Creek, Little Dry Creek, and Greenwood Gulch study area is located in unincorporated Douglas County and Arapahoe County including portions of the Cities of Lone Tree and Greenwood Village and the Southeast Metro Stormwater Authority (SEMSWA). The Willow Creek Watershed is approximately 9.5 square miles in area. Willow Creek, which is tributary to Little Dry Creek, is bounded on the south by Holly Street and Lincoln Avenue on the north.

The Little Dry Creek and Greenwood Gulch Watersheds border the Willow Creek Watershed to the north and are approximately 2.1 square miles and 1.6 square miles, respectively, within the study area. Both watersheds are bounded on the north by Interstate 25 with Holly Street defining the southern limits of the watersheds within the study area. Click here to view the Project Map.

GOALS

The purpose for this project is to develop an OSP that addresses storm runoff for the existing and future development conditions. The intent for the OSP is to provide a comprehensive master drainage plan that summarizes the existing hydrologic conditions and provides a framework for the development of drainage improvements in the watershed. Specifically, the project goals include the following:

Identify and understand how development will change the hydrologic characteristics of Willow Creek, Little Dry Creek and Greenwood Gulch.

Exchange information with and obtain input from the residences, landowners, developers, stakeholders, and project sponsors for the development of drainage solutions.

Develop and evaluate conceptual alternative plans for the outfall drainageway system considering stormwater conveyance, flood management, stream stability, and stormwater quality.

Identify the most appropriate outfall drainageway system for Willow Creek, Little Dry Creek and Greenwood Gulch.

Prepare an Alternatives Evaluation Report and Preliminary Design Report which also includes preliminary design drawings for the selected outfall drainageway system.

PROJECT SPONSORS

Urban Drainage and Flood Control District