Cal. Water Code § 47401

In case the assessment to be amended was not one made under Chapter 2 of this part, the board shall cause an amendatory assessment as to such land to be made upon the basis and in the manner in which the assessment to be amended was made. The proceedings for making, levying, and collecting such amendatory assessment shall be the same as those provided in this division for the making, levying, and collecting the assessment of which such assessment is amendatory. This assessment shall be made within two years after the making of the original assessment.