Any reclamation district, levee district, drainage district or municipal corporation, wholly or partly within the drainage district may with the permission of the board, construct levees, cuts, canals or gates required to complete any by-pass forming part of the plans to be carried out by the board, or to complete any part of any by-pass which may in the judgment of the board be safely and economically constructed as a separate unit or portion of the plans.
Ca. Water Code § 8997