7-12-4173. Status of federal property within improvement district. Whenever any lot, piece, or parcel of land belonging to the United States or mandatory of the government shall front upon the proposed work or improvement or be included within the district declared by the city council in its resolution of intention to be the district to be assessed to pay the costs and expenses thereof, said council shall, in the resolution of intention, declare that said lots, pieces, or parcels of land shall be omitted from the assessment thereafter to be made to cover the costs and expenses of said work or improvement. The cost of said work or improvement in front of said lots, pieces, or parcels of land shall be paid by the city from its general fund.