There are hereby authorized to be appropriated without fiscal year limitation, such sums as may be necessary to carry out the program authorized by this chapter. In carrying out the program, in each fiscal year through the fiscal year ending September 30, 1980, the Secretary shall not enter into agreements with owners and operators which would require payments to owners or operators in any calendar year under such agreements in excess of $10,000,000. In carrying out the program, in each fiscal year after the fiscal year ending September 30, 1980, the Secretary shall not enter into agreements with owners and operators which would require payments to owners or operators in any calendar year under such agreements in excess of $30,000,000. Not more than 15 percent of the funds authorized to be appropriated in any fiscal year after the fiscal year ending September 30, 1980, may be used for agreements entered into with owners or operators in any one State.