Upon receipt by the district of a copy of the agreement of annexation properly executed by the district and the public agency proposed to be annexed the board shall pass a resolution declaring the public agency annexed to the district. Thereupon the secretary of the district shall make the filings provided for in Chapter 8 (commencing at Section 56450, Government Code) of Part 5 of the District Reorganization Act of 1965. The annexation shall be complete and effective on the dates specified in said Chapter 8.