Robbin B. Sotir & Associates, Inc.

Case Study: Big Creek

Location: North Metro Atlanta, Georgia
Client: Atlanta Regional Commission
Objectives: Produce a technically defensible, integrated and cost effective management plan for the Big Creek Watershed.

• Development of a watershed protection master plan
• Improvement/maintain water quality of Big Creek and its tributaries
• Maximize recreational potential and property values
• Minimize flooding, property damages and stream impacts due to storm water runoff
• Educate the watershed’s users about the resource
• Promote intergovernmental cooperation in protecting the watershed

Nature of Firm's Resonsibility

Partnering with Fisch Engineering, Inc. 45 miles of stream reconnaissance was performed:
• Physical and environmental reach assessment
• Identify current and future erosion problems and their cause
• Agency and city meetings
• Categorize and prioritize the sites
• Development of alternatives for bank restoration and evaluate impacts
• Planning level cost estimating

Big Creek and its tributaries are located within a highly urbanizing watershed in the north metro Atlanta, Georgia area. The specific main stem of the Big Creek reach and six (6) tributaries addressed in this project is approximately forty-five (45) miles in length, located in commercial, industrial, residential, agricultural and undisturbed natural upland and wetland sites. This is a highly sensitive project with a variety of multi-objective goals specific to each stream's location and function in the watershed. A detailed physical and environmental reach assessment was performed. As an example, the physical assessment included information about the watershed (size and percent of impermeable surface), adjacent land use, riparian vegetation, channel and bank characteristics, erosion processes, stream type, geometry and substrate. The environmental assessment included parameters such as streambank epifaunal substrate/available overbank cover, morphological diversity and flow conditions, riparian vegetation zone width and riparian management potential.

Due to the continued development of the watershed, the Atlanta Regional Commission has taken this initial step to addressing and minimizing the effects of current and future urbanization and development within the Big Creek Watershed. The result of this effort will be the development of a technically defensible, integrated and cost effective management plan for the Big Creek watershed. The management plan will provide the Atlanta regional Commission with the capacity to understand current and future needs so that the participating jurisdictions can plan, budget and execute the appropriate activities to produce qualified decisions at the watershed level.

Due to the need for increased stormwater capacity and hydraulic efficiency, the environmental preservation and restoration concerns, developmental pressures and permitting authorities' requirements, the result of this type of study will serve as a model for other similar watershed planning activities in the Atlanta area.

Robbin B. Sotir & Associates, Inc. is serving as the watershed assessment and evaluation consultant to the Camp Dresser and McKee's interdisciplinary team is working directly with the Atlanta Regional Commission to complete the reconnaissance and recommendations. We anticipate completion by December 2000. Our work will be produced as a stand alone document.