Under the authority of the Replenishment Assessment Act of the Alameda County Water District, ACWD charges operators of water production facilities an assessment based on the quantity of groundwater produced. Replenishment assessment revenue helps pay for ACWD's work to replenish and maintain the Niles Cone Groundwater Basin. Replenishment assessment fees apply only to water production facilities in the ACWD-managed Niles Cone Groundwater Basin. Water wells, dewatering wells, and chemical investigation extraction wells are considered water production facilities.
Replenishment Assessment (RA) rates are reviewed annually; currently, the assessment is $8.00/acre-foot for agricultural and municipal-recreation uses (the maximum allowed under the Replenishment Assessment Act) and $437/acre-foot for all other uses.