Okla. Stat. tit. 11 § 37-104
Any municipality may purchase or condemn and hold the perpetual right to use any lots or lands, either within or without the corporate limits of the municipality, which the municipal governing body determines by resolution to be necessary for acquisition by the municipality in order to locate and build or enlarge, at the time or in the future, waterworks and every auxiliary part thereof, including reservoir site or sites to be flooded, and the lands adjacent thereto and within six hundred sixty (660) feet of the margin of the reservoir at maximum high water. The governing body may protect from possible contamination or pollution and police any such lands in order to protect any reservoir already constructed or proposed to be constructed or enlarged as a part of any municipal waterworks plant or water supply, the waters thereof, and the waters flowing therein or percolating or seeping thereto. The property and land so acquired before and after the passage of this subarticle, insofar as such lands are within six hundred sixty (660) feet of the margin of a reservoir at maximum high water and necessary for natural drainage into the reservoir, shall not be used by the municipality, its lessees or assigns, or other persons or corporations, for any purpose other than the protection of the reservoir and the waters thereof from contamination and pollution. No structures shall be placed on such lands by the municipality, individual or corporation, except as are necessary in the furtherance of the protection of the reservoir from contamination or pollution, and in the use of the water.
Okla. Stat. tit. 11, § 37-104