54 STAT.] 76TH CONG. , 3D SESS. -CH. 643-JULY 19, 1940 would have occupied had such charges, or the basis of computation thereof, and the method of operation which may be provided for under section 9 hereof, been effective on June 1, 1937: Provided, That such adjustments with contractors shall not be made in cash, but shall be made by means of credits extended over such period as the Secretary may determine. (b) In the event payments to the States of Arizona and Nevada, or either of them, under section 2 (c) hereof, shall be reduced by reason of the collection of taxes mentioned in said section, adjust- ments shall be made, from time to time, with each allottee which shall have paid any such taxes, by credits or otherwise, for that proportion of the amount of such reductions which the amount of the payments of such taxes by such allottee bears to the total amount of such taxes collected. SEC. 5. If at any time there shall be insufficient sums in the Colo- rado River Dam Fund to meet the cost of replacements, however necessitated, in addition to meeting the other requirements of this Act, or of regulations authorized hereby and promulgated by the Secretary, the Secretary of the Treasury, upon request of the Secre- tary of the Interior, shall readvance to the said fund, in amounts not exceeding, in the aggregate, moneys repaid to the Treasury pur- suant to Section 2 (b) hereof, the amount required for replacements, however necessitated, in excess of the amount currently available therefor in said Colorado River Dam Fund. There is hereby author- ized to be appropriated, out of any money in the Treasury not other- wise appropriated, such sums, not exceeding said aggregate amount, as may be necessary to permit the Secretary of the Treasury to make such readvances. All such readvances shall bear interest. SEC. 6. Whenever by the terms of the Project Act or this Act pay- ment of interest is provided for, and whenever interest shall enter into any computation thereunder, such interest shall be computed at the rate of 3 per centum per annum, compounded annually. SEC. 7. The first $25,000,000 of advances made to the Colorado River Dam Fund for the project shall be deemed to be the sum allo- cated to flood control by section 2 (b) of the Project Act and repay- ment thereof shall be deferred without interest until June 1, 1987, after which time such advances so allocated to flood control shall be repayable to the Treasury as the Congress shall determine. SEC. 8. The Secretary is hereby authorized from time to time to promulgate such regulations and enter into such contracts as he may find necessary or appropriate for carrying out the purposes of this Act and the Project Act, as modified hereby and, by mutual consent, to terminate or modify any such contract: Provided, however, That no allotment of energy to any allottee made by any rule or regulation heretofore promulgated shall be modified or changed without the consent of such allottee. SEC. 9. The Secretary is hereby authorized to negotiate for and enter into a contract for the termination of the existing lease of the Boulder Power Plant made pursuant to the Project Act, and in the event of such termination the operation and maintenance, and the making of replacements, however necessitated, of the Boulder Power Plant by the United States, directly or through such agent or agents as the Secretary may designate, is hereby authorized. The powers, duties, and rights of such agent or agents shall be provided by con- tract, which may include provision that questions relating to the interpretation or performance thereof may be determined, to the extent provided therein, by arbitration or court proceedings. The Secretary in consideration of such termination of such existing lease is authorized to agree (a) that the lessees therein named shall be 777 Proviso. Adjustments with contractors by means of credits. Adjustments with allottees for taxes paid. Treasury read. vances for replace. ment costs, etc., lim- itation. Appropriation au- thorized. Interest rate. Deferment of repay- ment of advances for flood control. 45 Stat. 1057. 43 U.S . C . 617a(b). Regulations and contracts. Proviso. Consent of allottee to modification of al. lotment of energy. Boulder Power Plant. Negotiations for ter- mination of existing lease.