The Atlanta Regional Commission has responsibility for:
A watershed is the area of land that drains to a common waterway, such as a stream, lake, estuary, wetland, or even the ocean. We all live in a watershed.
Watershed areas that drain to major rivers are typically called river basins and are made up of many smaller watersheds. In the Atlanta region, there are five major river basins. Three of these, the Chattahoochee, Flint and Coosa river basins eventually flow to the Gulf of Mexico. The other two, the Oconee and Ocmulgee drain to the Atlantic Ocean.
Assesing the entire watershed is important in addressing pollution as well as protecting drinking water supplies. Effective watershed management is key to protecting and preserving the Atlanta region’s quality of life and economic vitality.
The Stormwater Runoff Problem
After it rains, some of the water runs off the land, rather than soaking into the ground. This stormwater flows downhill to the nearest storm drain, stream, river or lake.
In an undeveloped watershed, most of the rain is absorbed into the soil and taken up by vegetation, with only a small amount of runoff occurring. As a watershed is developed, impervious surfaces such as buildings, parking lots and roadways prevent rainfall from infiltrating the ground. This results in increased stormwater runoff which can cause flooding and stream bank erosion.
In addition, stormwater runoff picks up a number of pollutants as it flows off of rooftops, lawns, streets and parking lots. These contaminants include sediment (dirt), leaves, grass clippings, fertilizers and pesticides, oil and grease, litter, heavy metals and animal waste. All of these can cause water quality problems in the receiving water body.
Addressing Stormwater Problems
Communities in the Atlanta region are addressing these issues through watershed and stormwater management. This involves a number of programmatic activities designed to mitigate the impact of stormwater runoff problems including requirements for new development projects, effective erosion and sedimentation control, floodplain management, pollution prevention, illicit discharge elimination and stormwater system inspection and maintenance.
The Georgia Stormwater Management Manual, an ARC effort, provides guidance on stormwater management policy, technical design standards and pollution prevention with the goal of reducing stormwater impacts to our communities and shared water resources.
Leading the Way to Cleaner Streams
Many streams in Georgia are not meeting state water quality standards. To help local governments clean up these streams, Georgia's Environmental Protection Division (GA EPD) has studied the maximum amount of pollution a stream can receive and still meet water quality standards. These limits are called Total Maximum Daily Loads (TMDLs).
The Atlanta Regional Commission (ARC) helps local governments to develop plans to meet these water quality standards. For more information on the TMDL process please visit the U.S. Environmental Protection Agency Web site.