Cal. Sts. & Hy. Code § 5821
The board of supervisors may, in its resolution declaring its intention to order work done or improvements made or by separate resolution, declare its intention to order that the expenses of maintaining and operating any or all of said improvements or any or all other improvements such as are permitted to be constructed herein, including the cost of necessary repairs, replacements, fuel, power, electrical current, care, supervision, and any and all other items necessary for the proper maintenance and operation thereof, shall be assessed, either partly or wholly, upon the real property or upon the land only lying within the district to be benefited by and to be assessed to pay the cost of the construction of said improvement, or upon such district as the board of supervisors shall determine will be benefited by the maintenance and operation of the improvements proposed to be maintained; the amounts so assessed to be levied and collected in the same manner and by the same officers as taxes for county purposes are levied and collected.
Ca. Sts. and High. Code § 5821