If the board determines, pursuant to the provisions of this part, that bonds should be issued, an action to determine the validity of the assessment may be brought pursuant to Chapter 9 (commencing with Section 860) of Title 10 of Part 2 of the Code of Civil Procedure.

No objection to the assessment shall be considered by the court unless the objection has been made in writing to the board as provided in Part 4 of this division.

The judgment shall refer to the assessment apportioned to each county separately and it shall be sufficient to refer to the portions of the assessment which are affected by the judgment.

Unless the aggregate amount of the whole of the assessment is modified or amended by the judgment in the proceedings so as to cause a difference of more than 21/2percent greater or less than the original total amount of the assessment, the assessment shall not be deemed to have been substantially modified and no necessity shall exist for a reapportionment thereof.

The assessment lists, unless annulled by the judgment in the judicial proceeding, embracing any modifications made by the judgment are conclusive evidence that the assessment has been apportioned according to the benefits that will accrue to each tract of land in the drainage district by reason of the expenditure of the sums of money to be raised thereby.

A certified copy of the judgment referring to the assessment lists shall be filed in the office of the board.

A certified copy of so much of the judgment as relates to the lands in each of the counties affected thereby shall be affixed to the original assessment list for such county and the board shall thereupon cause such amendments or modifications to be made and entered upon the original assessment lists as may be necessary to make them conform to the provisions and directions of the judgment.

The assessment lists as amended or modified shall be certified by the secretary or assistant secretary of the board as being in conformity with the requirements of the judgment.