If the district shall file its objections in the manner aforesaid to the annexation to the district of such territory or portion thereof, the territory, or portion thereof, shall not be annexed to the district except in the manner provided in Articles 1 (commencing with Section 26401), 2 (commencing with Section 26421), 3 (commencing with Section 26451) and 4 ( commencing with Section 26486) of this chapter. The district may withdraw such objections by filing with the city clerk a certified copy of a resolution of the board stating that such objections are withdrawn. Thereupon said territory, or portion thereof, shall be deemed incorporated into and annexed to the

district as provided in Section 26511.