“(a) Fiscal years 2021 and thereafter.—

“(1) IN GENERAL.—For fiscal year 2021 and each fiscal year thereafter, of the amounts made available for the fiscal year, the Administrator shall make allotments to States and territories and possessions of the United States in accordance with this subsection.

“(2) FISCAL YEARS 2021 AND 2022.—

“(A) CERTAIN TERRITORIES AND POSSESSIONS.—Notwithstanding any other provision of this section, subject to subparagraph (C), for each of fiscal years 2021 and 2022, of the amounts made available for the fiscal year, the Administrator shall initially provide under this subsection to each territory or possession of the United States (other than the Commonwealth of Puerto Rico) an allotment of not less than the allotment described in the following table:

“(B) STATES, DISTRICT OF COLUMBIA, AND PUERTO RICO.—Notwithstanding any other provision of this section, subject to subparagraph (C), for each of fiscal years 2021 and 2022, of the amounts made available for the fiscal year remaining after the allotments under subparagraph (A) are provided, each State, the District of Columbia, and the Commonwealth of Puerto Rico shall receive an allotment under this subsection of not less than the allotment described in the following table:

“(C) LIMITATION.—Notwithstanding any other provision of this section, for each of fiscal years 2021 and 2022, the Administrator may not decrease the amount provided to any State or territory or possession of the United States under this section by more than—

“(i) a percentage below the amount provided to the State or territory or possession of the United States under this section for fiscal year 2019 that is equal to the percentage decrease in total funding under this section, as compared to that total funding for fiscal year 2019, if the total funding remains below 95 percent of that fiscal year 2019 funding level; or

“(ii) 5 percent below the amount provided to the State or territory or possession of the United States under this section for fiscal year 2019, if the total amount of funding under this section remains at or above 95 percent of that fiscal year 2019 funding level.

“(3) ALLOTMENT UPDATES.—

“(A) IN GENERAL.—The Administrator shall update the tables contained in paragraph (2) through application of the formula developed pursuant to subparagraph (B)—

“(i) by not later than September 30, 2022, to ensure updated allotments are in effect for fiscal year 2023; and

“(ii) thereafter, by not later than 1 year after the date of submission of any new clean watersheds needs survey and associated data under section 516(b)(1)(B).

“(B) FORMULA.—

“(i) IN GENERAL.—The Administrator shall develop, by regulation, a formula for the calculation of allotments to States and territories and possessions of the United States under this section, in accordance with clauses (ii) and (iii).

“(ii) REQUIREMENTS.—

“(I) BASES.—The formula under clause (i) shall be developed based on—

“(aa) the State needs identified in the most recently available clean watersheds needs survey prepared by the Administrator under section 516(b)(1)(B);

“(bb) the State population results of the most recent decennial census; and

“(cc) the most recently available water quality impairment component ratio published by the Administrator for purposes of this Act.

“(II) WEIGHT.—In developing the formula under clause (i), the Administrator shall give—

“(aa) 50 percent weight to the survey referred to in subclause (I)(aa);

“(bb) 30 percent weight to the census referred to in subclause (I)(bb); and

“(cc) 20 percent weight to the ratio referred to in subclause (I)(cc).

“(iii) LIMITATION.—Notwithstanding clause (ii), in developing the formula under this subparagraph, the Administrator may not increase the allotment to any State or territory or possession of the United States by more than 200 percent, or decrease the allotment to the State, territory, or possession by more than 25 percent, as compared to the allotment level established for the State or territory or possession of the United States under the previous formula.”;