California Code, Water Code - WAT § 35454.5

In any year in which the board of a district not having meters or other volumetric measuring instruments or facilities to measure substantially all agricultural water to be delivered concludes the available water supply will be inadequate to serve all land entitled to service that will probably desire such service, the district may establish reasonable annual water requirements for growing each type of crop grown or likely to be grown in the district in that year;  determine the maximum acreage of each crop that each holder of title to land, or his duly authorized agent or tenant, may irrigate with district water by dividing the quantity of water apportioned or apportionable to him by such reasonable annual water requirements so established by the district;  limit the acreage of each crop that each such holder of title to land, or his duly authorized agent or tenant, may irrigate with district water to the maximum acreage or acreages so determined;  and refuse to deliver water to, or assess penalties on, a holder of title to land, or his duly authorized agent or tenant, who uses district water on a greater acreage of such crops.

Nothing in this section shall prohibit or limit the application of the provisions of Section 35453 or 35454.  This section provides a means of measuring the allocation of water to lands based on the type of crop grown and does not authorize a district to designate the crops to be grown on such land.