Cal. Wat. Code § 35003
Each voter shall have one vote for each dollar's worth of land to which he or she holds title. The last equalized assessment book of the district is conclusive evidence of ownership and of the value of the land so owned except that in the event that an assessment for a district shall not have been made and levied for the year in which the election is held, the last assessment roll of each affected county shall be used in lieu of the assessment book of the district as evidence of ownership. However, the board may determine by resolution that the assessment book or assessment roll of each affected county shall be corrected to reflect, in the case of transfers of land, those persons who as of the 45th day prior to the election appear as owners on the records of the county. If an equalized assessment book of the district does not exist, then each voter shall be entitled to cast one vote for each acre owned by the voter within the district, provided that if the voter owns less than one acre then the voter shall be entitled to one vote and any fraction shall be rounded to the nearest full acre.
Ca. Water Code § 35003