The amount of any replenishment assessment levied within an area of benefit shall be established at the discretion of the board, except that no assessment shall exceed the sum of the following costs and charges:
(a)
Those charges imposed under the contract between the district and the state for an imported water supply from the State Water Resources Development System consisting of all of the following:
(1)
The variable operation, maintenance, power, and replacement component of the transportation charge.
(2)
The off-aqueduct power facilities component of the transportation charge.
(3)
The delta water charge.
(4)
Any surplus water or unscheduled water charge.
(5)
Sums paid by the district to the Desert Water Agency for payment of similar charges under a similar contract the agency has with the state as provided in the water management agreement of July 1, 1976, as amended.
(b)
The cost of recharging the groundwater basin with imported water from the State Water Resources Development System not included in subdivision (a).
(c)
The cost of importing and recharging water from sources other than the State Water Resources Development System.
(d)
The cost of treatment and distribution of reclaimed water for recharge or for direct use in lieu of groundwater.
(e)
The cost of programs providing incentives to use reclaimed water or Colorado River water in place of groundwater.