California Code, Public Resources Code - PRC § 26581

At any time following the adoption of the resolution pursuant to Section 26567, the board of directors may proceed to annex territory to the district. The proceedings for annexation shall follow the procedure contained in Article 3 (commencing with Section 26550) and Article 4 (commencing with Section 26561) of Chapter 2 of this division. In such instance, the board of directors shall assume the responsibilities of the legislative body. Annexation of territory to a district shall be subject to the approval of the legislative body which ordered formation of the district. Such approval shall be given by resolution, following the order by the board of directors for annexation of territory to the district.