yield: (1) Specific yield of aquifers, an estimation. The volume of water that can be drained by gravity from the pores of sand, gravel, soil, or rock divided by the total volume of material and expressed as a fraction or percent. GWAC.

This method applies to gravity drainage and describes yield without regard to the porosity of an aquifer. This is the method recommended in Senate Bill 5 by the Colorado legislature. See Senate Bill 5, capillarity, buoyancy, drainage and recovery factor. Compare irreducible water. See also equity and equity determination.

(2)The volume of water diverted by a water right. Yield may be expressed as an average for a period of years (average yield) or as the yield of one selected year representing the lowest or critical amount of water provided (critical year yield). Yield also may refer to diversion at the headgate (headgate yield) or at the farm turnout where it is applied to irrigation (farm yield). The difference between headgate yield and farm yield is the amount of water lost to seepage and other causes related to the conveyance of water through the ditch.

(3) See also safe yield.