Watershed master planning, City of Griffin, Georgia, USA

Abstract

Tetra Tech has assisted the City of Griffin, Georgia (City) since 2003 with their stormwater and watershed planning needs. To date, work has included geomorphic assessments of streams, watershed modeling, Watershed Management Plans, a Stormwater Master Plan, and a Stormwater Capital Cost Recovery Plan. The effort has followed a holistic approach that includes the evaluation of problems and opportunities at the site and subwatershed scale, while considering cost-effectiveness and environmental sustainability at the watershed scale. Funding for these projects has come through the City’s stormwater utility, which was the first one in the State of Georgia. Tetra Tech has developed Watershed Management Plans for each of the City’s three major watersheds. Each plan includes three components: a Watershed Monitoring, Assessment, and a Protection Plan. The Watershed Assessments characterize the watersheds and identify problems and management needs in each subwatershed. The Watershed Protection Plans lay out a strategy for addressing the problems through a combination of programmatic measures, stormwater Best Management Practices (BMPs), and stream restoration projects. In order to provide a mechanism for the City to help fund the recommended BMPs, Tetra Tech developed a Stormwater Capital Cost Recovery Plan which establishes a watershed impact fee for new development and re-development. The planning documents that Tetra Tech developed for the City’s Stormwater Division all work together to support a path forward that has specific goals, a well-defined implementation plan, and the financial mechanisms necessary for success. The process that Tetra Tech used to evaluate watershed needs and develop planning and guidance documents is innovative, practical, and applicable to other local and regional watershed planning efforts.