- acre foot
- (ac ft or af)a unit of volume used to measure the capacity of reservoirs. One acre foot is a volume one foot deep covering an area of one acre. Thus an acre foot contains exactly 43 560 cubic feet, about 325 851.4 U.S. gallons, or about 1233.482 cubic meters (0.123 348 hectare meter). The symbol af is widely used in reservoir management in the U.S., often in combinations such as kaf (1000 acre feet) or maf (million acre feet; this symbol should be Maf).
Dictionary of units of measurement. 2015.