Cal. Wat. Code § 51324.5
In preparation of the operation and maintenance assessment roll, the commissioners may, as one of the means of determining the assessment valuation per acre of each parcel, establish a base value per acre for each parcel of land according to the land use category or type of land use category for the parcel as reflected on the records of the county assessor. The base value may be adjusted to reflect the benefits derived by the parcel from continuance in operation of the district reclamation works in accordance with the benefit formula adopted by the commissioners. If land use categories are utilized by the commissioners, they shall file, with the operation and maintenance assessment roll, a report describing the basis for identifying the categories or category types utilized in establishing the assessment valuation per acre and the basis for future adjustment of that valuation, pursuant to Section 51346.5, to reflect changes in the land use category or type of land use category shown for each parcel on the records of the county assessor.
Ca. Water Code § 51324.5