The Secretary of the Interior is authorized to contract for the delivery of water to public organizations or agencies for use within the boundaries of such organizations or agencies for waterfowl purposes in the Grasslands area of the San Joaquin Valley. If and when available, such water shall be delivered from the Central Valley project to the contracting entity, and the cost of furnishing the water shall not be reimbursable or returnable under the Federal reclamation laws: Provided, That, in order for the delivery of such water to continue on a nonreimbursable or nonreturnable basis—

(a) Amount and time of water delivery to Service
the public organizations or agencies contracting with the Secretary of the Interior, excluding the State of California, shall deliver annually to the United States Fish and Wildlife Service (hereinafter referred to as the "Service"), at no cost to the United States, not less than three thousand five hundred acre-feet of water during the period October 1 through November 30, inclusive, and not less than four thousand acre-feet of water during the period May 1 through September 30, inclusive, if available: Provided, That such amounts of water and times of delivery may be changed upon approval of the Secretary of the Interior;

(b) Construction, operation, and maintenance of water conveyance facilities
the public organizations or agencies, excluding the State of California, shall construct, operate, and maintain any water conveyance facilities necessary to deliver the water referred to in subsection (a) of this section to a point or points within the boundaries of such public organization or agency as designated by the Service, or to such points as may be mutually agreed upon by the public organization or agency and the Service. The Service shall be responsible for delivering the water from such point or points to appropriate locations within lands under its jurisdiction;

(c) Reversionary rights of Secretary
any contract entered into by the Secretary of the Interior and any public organization or agency pursuant to sections 695d to 695j–1 of this title shall provide that in the event the public organization or agency for any reason fails to carry out the obligations imposed upon it by said contract or by sections 695d to 695j–1 of this title, the rights of use of any facilities referred to in subsection (b), and the rights to all water contracted for by the organization or agency pursuant to sections 695d to 695j–1 of this title shall revert to the Secretary of the Interior for migratory waterfowl purposes in accordance with the laws of the State of California; and

(d) Restrictive covenants
in accordance with existing or future contracts, the use of lands located within the boundaries of the public organizations or agencies shall be restricted by covenants requiring that such lands be used only for the purpose of waterfowl and wildlife habitat conservation or other uses as may be mutually agreed upon by the public organizations or agencies and the Service.