Cobb County Watershed Restoration

Client: USACE Mobile District and Cobb County

Location: Cobb County, GA

Summary:

Cardno ENTRIX worked for the Mobile District of the USACE as a part of a multidisciplinary team to develop restoration alternatives for several intensely developed watersheds in Cobb County, Georgia. The purpose of this project was to develop data and prepare specific portions of three Preliminary Restoration Plans (PRPs) in the Savannah River Basin and three Environmental Restoration Reports (ERRs) in the Mobile River Basin for Section 206 Aquatic Ecosystem Restoration studies in north Georgia. In Spring 2004 Cardno ENTRIX?s tasks were terminated due to funding constraints prior to completion of the ERRs.

Once complete, the ERRs will examine restoration alternatives for three tributary watersheds to Lake Allatoona in Cobb County: (1) Butler Creek (6,016 acres); (2) Proctor Creek (4,928 acres); and (3) Allatoona Creek (11,648 acres). The project will identify problem areas throughout each of the three watersheds through detailed stream walks and a study of the fish community and develop a list of restoration measures that can be used to improve aquatic habitat conditions within each of the watersheds.

Cardno ENTRIX staff evaluated over 80 miles of streams and prioritized important stream reaches that should be considered for stream restoration based on the results of the detailed stream walks. Cardno ENTRIX also helped identify potential locations for retrofitting or building new storm water BMPs that could be used to reduce peaks flows and improve physical habitat conditions with the each of the watersheds. A series of three restoration alternatives will be evaluated using a water quality model to determine the alternative that has the greatest removal of total suspended solids (TSS) given future land use conditions. Removal of TSS will be compared to the relative cost of each alternative to select the preferred alternative.

Cardno ENTRIX has also provided support to public involvement and agency coordination. Because a federally threatened darter occurs in each of the watersheds under study, agency coordination is an important step to receive approval and acceptance for constructing the restoration projects once the planning process is completed. With USACE staff taking the lead, Cardno ENTRIX has attended several public and resource agency meeting and provided technical input and discussed the various restoration alternatives at these meetings.