Cal. Water Code - WAT § 47400. Section 47400.
The board shall levy an amendatory assessment in the manner provided for original assessments in Chapter 2 of this part if the original assessment was one levied pursuant to Chapter 2 of this part and any of the following occur:
(a)
Any land within the district is omitted from any assessment roll.
(b)
Land appears in the assessment roll but is neither assessed nor stated not to be assessed.
(c)
A final judgment of a court of competent jurisdiction has held that any assessment is
invalid as to any part of the land assessed.
This amendatory assessment shall be based upon a determination, as nearly as may be, of the amount the original assessment upon the land would have been except for the omission or invalidity.