Cal. Wat. Code § 35539
In addition to, and as an alternative to, the powers contained in this division, the board may by resolution determine and declare that it is necessary to levy a special assessment of an equal amount upon each acre of developed land, upon each acre of undeveloped land, or both, within the district or within zones established pursuant to Sections 35534 and 35535 in order to cause just and equitable sharing among the district's landowners of all or any portion of the district obligations for the next year in excess of receipts from water charges, as reflected in the district's annual estimate of obligations filed pursuant to Section 36552 or 37206, and such resolution shall declare that a public hearing shall be held thereon at a specified time and place at which all interested persons may appear and be heard.
Ca. Water Code § 35539