Notwithstanding any other provision of this subchapter, in the event of a natural disaster, so declared by the President under the Robert T. Stafford Disaster Relief and Emergency Assistance Act [42 U.S.C. 5121 et seq.], the Secretary shall allocate, for assistance under this section to the States affected for use in the counties designated as disaster areas and the counties contiguous to such counties, amounts made available to the Secretary by an appropriations Act for such purpose. Allocations under this section may be made for each of the fiscal years ending during the 3-year period beginning on the declaration of the disaster by the President.