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What is a Watershed?

an illustration of a Watersheds landscape on the left and a cobb county map on the right showing the Kennesaw Mountain Ridgeline

Watershed: Defined

Cobb County is approximately 300 square miles with 3,200 miles of stream channel. 54% of Cobb County is residential, 22% municipalities, 11% greenspace, 5% commercial, 5% government, and 3% industrial.

Drainage Areas

Cobb County is located in the Piedmont ecoregion and is bisected by the Kennesaw Mountain ridgeline. This topographic feature, consisting of several high points crossing the jurisdiction west to east, includes Lost Mountain, Little Kennesaw Mountain, Kennesaw Mountain, Blackjack Mountain, and Sweat Mountain. When rain falls north of the ridgeline, the water flows into streams of the Etowah Watershed: Allatoona Creek, Butler Creek, Little Allatoona, Little Noonday, Noonday Creek, Proctor Creek Rubes Creek, and Tanyard.

When rain falls south of the ridgeline, the water flows into streams of the Chattahoochee Watershed: Nickajack Creek, Rottenwood Creek, Sewell Mill Creek, Sope Creek, Sweetwater Creek, Willeo Creek. In addition, several streams make up the Sweetwater Creek system: Buttermilk Creek, Mud Creek, Noses Creek, Olley Creek, Powder Springs Creek, and Ward Creek.

The Landscape

Historical documentation indicates that Cobb County was once dense pine and mixed hardwoods. Upon European settlement, extensive clearing for agriculture occurred. Topsoil was lost and sand was added to the fields for cotton, a major crop from early 1800-early 1900. The streams were likely impacted during this period. As agriculture declined from 1930-1960, fields turned into pastures for livestock grazing and returned to forests. The landscape was stable until the growth boom and subsequent land disturbing activities occurred. We are observing the results of all these activities today.

Local Water Quality

Our main water quality issues are stressors from impervious surface area runoff including chemical pollutants (fertilizers and pesticides), bacteria (pet waste), elevated water temperature, sediment, excessive streamflow volume, and non-native invasive species. The Watershed Stewardship Program educates the community about these concerns and provides feasible activities to address these issues.