A bill to authorize the Secretary of the Interior to construct, operate, and maintain the Grass Rope Unit of the Pick-Sloan Missouri Basin Program, South Dakota, and for other purposes.

Reauthorizes the Grass Rope unit, South Dakota, as part of the Pick-Sloan Missouri Basin program. Directs the Secretary of the Interior to construct, operate, and maintain such unit for irrigation, wildlife mitigation, and other purposes. Authorizes the Secretary to acquire lands and estimates necessary for such project.

Sets forth provisions for the repayment of capital costs of such unit. Authorizes the Secretary to transfer operation and maintenance of such unit to the Lower Brule Sioux tribal government or other qualified entity.

Modifies Federal reclamation laws to limit land eligible to receive water from such unit to 160 acres of singly-owned land, exempting Indian trust lands.

Requires the Secretary of the Treasury to determine the interest rate on the construction and other costs of such unit.