Wat. Code, § 23242.5

The contract between a district and the United States may, subject to hearing and equalization as provided herein, determine, or provide for the method of computation of, the benefits accruing to each parcel of land within the district from the agreement of the district to pay the construction charges applicable to such lands to the United States; and such determination or provision in the contract may be amended from time to time.

If the district shall determine to apportion the assessment required in any year to meet the payment due to the United States on account of such construction charges in accordance with such benefits it shall establish for each parcel of land an appropriate period of years over which such benefits should be paid (which periods may be different as to different parcels), and thereby determine the amount applicable to the year in question. The annual assessment on each parcel shall be equal to the amount so determined increased by such a percentage as shall, in the opinion of the board, be deemed sufficient to cover anticipated delinquencies.

The secretary shall thereupon include an announcement of apportionment according to benefits in the notice provided for in Section 25550. At the meetings of the board as a board of equalization it may hear and determine objections to the assessment and order any changes that it deems just. Within 15 days after the close of its session as a board of equalization the board shall levy the assessment, the secretary shall transmit a record thereof to the collector, and thereafter the assessment shall be collected as in the case of other district assessments.