CA Educ Code Section 74251

(a)

An action to reorganize districts is complete when the board of supervisors makes the order pursuant to Section 74250.

(b)

After the expiration of one year from the date of the order, the order shall be conclusive evidence that the district has been legally organized, or the boundaries legally changed, as the case may be, and no suit shall be maintained which questions the validity of the organization or change of boundaries.

(c)

For purposes of district tax revenues and governance, the order shall be effective as of the beginning of the succeeding fiscal year.