The board of supervisors shall immediately cause a copy of the order declaring the district formed, duly certified by the clerk of the board, to be filed for record in the office of the county recorder of any county in which any portion of the lands embraced in the district is situated, and shall also immediately forward a copy thereof to the clerk of the board of supervisors of each of such counties. From and after such filing, the formation of the district is complete.
Ca. Water Code § 74121