Upon the completion of the annexation or inclusion of the unincorporated territory described in Section 8290 to a city, the clerk of the legislative body of such city shall so notify the secretary of the commission of the district and shall furnish such secretary with a certified copy of the ordinance or resolution adopted by the legislative body of such city annexing or including said territory to such city and of the resolution determining what portion or portions of the territory should not be included in the district because not benefited by such inclusion.