Section 111
SEC. 111. The beneficial use of water shall be the basis, the measure, and the limit of all rights thereto, and the patents herein granted shall be subject to the right of the Government to make such rules and regulations for the use of water and the protection of the water supply, and for other public purposes, as it may deem best for the public good. Whenever, by priority of possession, rights to the use of water for mining, agricultural, manufacturing, or other purposes have vested and accrued, and the same are recognized and acknowledged by the local customs, or by the laws and decisions of the courts, the possessors and owners of such vested rights shall be maintained and protected in the same, and all patents granted under this Act shall be subject to any vested and accrued rights to ditches and reservoirs used in connection with such water rights as may have been acquired in the manner above described prior to April eleven, eighteen hundred and ninety-nine.