Instream Flow Protection

In Georgia, we enjoy water as a public good for equitable use by all citizens; however, that public good must be regulated to prevent harm to the resource. Pursuant to Georgia’s Surface Water Use Act (O.C.G.A.12-5-31), anyone who wishes to withdraw 100,000 or more gallons of water per day from any surface water must apply for a permit. These permits are not to be issued if they would result in unreasonable adverse impacts on downstream users. For a list of withdrawal permits, click here.

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 (cfs). 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 “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 stated that the 7Q10 standard was not adequate to maintain aquatic habitat, which thrives on variable, seasonal flows.

In 2001, UCR 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.

A fact sheet prepared by the Georgia Water Coalition summarizes this issue.

For examples of UCR cases, see Enforcement Highlights—Instream Flow.