; and operation and maintenance of aircraft, $914,899,000, to remain available until September 30, 2025, of which $19,144,913 shall be for the purposes, and in the amounts, specified for this account in the table titled Community Project Funding/Congressionally Directed Spending in the explanatory statement described in section 4 (in the matter preceding division A of this consolidated Act): Provided, That appropriations hereunder shall be available pursuant to 7 U.S.C. 2250 for construction and improvement of buildings and public improvements at plant materials centers, except that the cost of alterations and improvements to other buildings and other public improvements shall not exceed $250,000: Provided further, That when buildings or other structures are erected on non-Federal land, that the right to use such land is obtained as provided in 7 U.S.C. 2250a: Provided further, That of the total amount available under this heading, $7,000,000 shall be for necessary expenses to carry out the Urban Agriculture and Innovative Production Program under section 222 of subtitle A of title II of the Department of Agriculture Reorganization Act of 1994 ( 7 U.S.C. 6923 ), as amended by section 12302 of Public Law 115–334 . WATERSHED AND FLOOD PREVENTION OPERATIONS For necessary expenses to carry out preventive measures, including but not limited to surveys and investigations, engineering operations, works of improvement, and changes in use of land, in accordance with the Watershed Protection and Flood Prevention Act (16 U.S.C. 1001–1005 and 1007–1009) and in accordance with the provisions of laws relating to the activities of the Department, $35,000,000, to remain available until expended, of which $20,350,000 shall be for the purposes, and in the amounts, specified for this account in the table titled Community Project Funding/Congressionally Directed Spending in the explanatory statement described in section 4 (in the matter preceding division A of this consolidated Act): Provided, That for funds provided by this Act or