Instream flow is the amount of water needed in a stream to adequately provide for downstream uses occurring within the stream channel. These users cover some or all of the following uses that extend beyond the need for human drinking water: aquatic habitat, recreation, wetlands, navigation, hydropower, riparian vegetation, and water quality, including waste assimilation. Flow is measured in volume of water per unit of time, usually cubic feet per second. This gauges the amount of water flowing past a point in the river at a given time.


For many years, Georgia used a flow standard that was protective of water quality, in most cases, but not protective of aquatic habitat. This 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 stated that the standard was not adequate to maintain aquatic habitat, which thrives on variable, seasonal flows.

How CRK Makes a Difference

In 2001, CRK helped ensure the adoption of an Interim Instream Flow Policy by the Georgia Board of Natural Resources, effective April 1, 2001. This policy, which is to be used until scientific research can determine the best final policy for the state, provides three options for water withdrawers to use in their permit applications.

For More Information

Visit the LexisNexis® website, the official publisher of the Official Code of Georgia Annotated and search for the Surface Water Use Act (O.C.G.A.12-5-31). The act requires a permit of anyone wishing to withdraw 100,000 or more gallons of water per day from any surface water. These permits are not to be issued if they would result in unreasonable adverse impacts on downstream users.