Enough Water to Ensure Healthy Rivers

Maintaining an adequate instream flow is critical to protect water quality and preserve aquatic habitat. For many years, Georgia used a flow standard that was protective of water quality, in most cases, but not protective of aquatic habitat. This “7Q10” flow standard, dictated that the lowest seven-day continuous flow at a particular point in a stream over a ten-year period should be the minimum flow required. Scientists questioned this standard, and a report published by Georgia’s Wildlife Resources Division in 1995 (click here to download pdf) stated that the 7Q10 standard was not adequate to maintain aquatic habitat, which thrives on variable, seasonal flows.

In 2001, the Board of the Department of Natural Resources (DNR) adopted an Interim Instream Flow Policy (click here to download pdf) to be used until scientific research could determine the best final policy for Georgia. This Interim Policy does not include main stem rivers that are highly regulated by federal dam projects, such as the Chattahoochee and Coosa Rivers. Tributaries to these rivers would be protected by this policy, which provides three options for water withdrawers to use in their permit proposals.

Protecting Instream Water Quality Below Peachtree Creek

More than 30 years ago, the state passed a regulation mandating that a minimum of 750 cubic feet per second of water be maintained at all flows in the Chattahoochee at the confluence of Peachtree Creek in Atlanta. Several major wastewater discharges occur in this area, and the 750 cfs flow was determined to be sufficient to ensure that the dissolved oxygen standard would be met at all times. Upstream dams, especially Buford Dam, regulate the river flow to achieve this flow standard. It has been argued that new research and studies are needed to re-evaluate this flow level, given the anticipated upstream growth and increasing water withdrawals and discharges.