From the sums appropriated pursuant to section 1962c of this title for any fiscal year the Council shall from time to time make allotments to the States, in accordance with its regulations, on the basis of (1) the population, (2) the land area, (3) the need for comprehensive water and related land resources planning programs, and (4) the financial need of the respective States. For the purposes of this section the population of the States shall be determined on the basis of the latest estimates available from the Department of Commerce and the land area of the States shall be determined on the basis of the official records of the United States Geological Survey.