43 U.S.C. § 415: Receipts applicable to project generally

All moneys heretofore or hereafter refunded or received in connection with operations under the reclamation law, except repayments of construction and operation and maintenance charges, shall be a credit to the appropriation for the project or operation from or on account of which the collection is made and shall be available for expenditure in like manner as if said sum had been specifically appropriated for said project or operation.