43 U.S.C. § 390tt: Contract required

Irrigation water temporarily made available from reclamation facilities in excess of ordinary quantities not otherwise storable for project purposes or at times when such irrigation water would not have been available without the operations of those facilities, may be used for irrigation, municipal, or industrial purposes only to the extent covered by a contract requiring payment for the use of such irrigation water, executed in accordance with the Reclamation Project Act of 1939 [ 43 U.S.C. 485 et seq.], or other applicable provisions of Federal reclamation law.