Water School

What is an acre-foot?

An acre-foot is commonly used to measure water volume. It is the amount of water needed to cover one acre (43,560 square feet) with one foot of water. One acre-foot is equal to 325,851 gallons of water, enough to cover a football field with a foot of water.

Measuring acre footage is an important way to calculate the volume of large water resources, like irrigation sources, reservoirs, sewers, canals, and human-made lakes, such as Possum Kingdom Lake, which is located in Palo Pinto, Jack, Young, and Stephens counties.

This water supply reservoir holds about 540,000-acre-feet of water and almost half is available as water supply for the Brazos River basin. With 230,750-acre-feet available for water supply, it is important to measure any changes in the amount of water available. 

Without a tool to measure the volume of water, it would not only be difficult to know how much water is in an area, but it would also make it hard for organizations like the Brazos River Authority from acting proactively to prevent water loss. 

More info:

For more information, read: 

•    When water seemingly vanishes
•    Water Education Foundation 
•    Possum Kingdom Lake


Return to Water School to learn more about water!


Not any article



The information provided on this site is intended as background on water within the Brazos River basin. There should be no expectation that this information is all encompassing, complete or in any way examines every aspect of this very complex natural resource.

If you have questions about a post or would like additional information, please contact us or call 888-922-6272.

costs brackish solids calcium drought water treatment gage governance environment watercourse USGS system Board septic system clarity canoe water use reservoirs riparian channel acre-feet parasite subsidence district permit fertilizer dam agricultural chlorine sediment bay medicine lawn fish kill treatment main stem emergency use golden algae acre-foot boating kayak releases employment rain lake levels municipal meta tag impound bottled water flood pool aerobic monitor appropriation stream wastewater gas flood lake industry PAM speaker consumption aquifer corps of engineers river minerals biosolids granbury limestone riverine spillway bed and banks basin farming invasive plants direct re-use well water planning drilling measure electricity smell hydrologic cycle wetland storage E coli taste pollutants pharmaceuticals streamflow fork indirect re-use rights anaerobic water cycle classification water plants volume lakes corps insurance conservation surface water environmental ground water TCEQ algae jobs contaminants depth gate E. coli recreation marsh sludge sanitation salinity legislation flood control lake xeriscape hydrology water contract streamflow runoff beneficial use infection dock lake level climate reservoir fishing chlorides evaporation agriculture turbidity sewage map soil electric companies landscaping spring hydrilla mainstem watershed quality mitigation industrial hunting allens creek reservoir potable oxygen possum kingdom inundated dissolved solids water clarity septic subwatershed planning canoeing hydropower estuary use drinking water inland cfs water quality camping authority maps effluent salt mission groundwater gulf water supply mgd precipitation subsidence wildlife organic water rights habitat tributary filter golden algea water code wetlands supply