This Act may be cited as the Enhancing Science, Treatment, and Upkeep of America’s Resilient and Important Estuarine Systems Act or the ESTUARIES Act.

Section 320 of the Federal Water Pollution Control Act (33 U.S.C. 1330U.S. Code — Title 33, Section 1330View official source on GovInfo) is amended— (1) in subsection (a)(2)(B), by striking and Pensacola and Perdido Bays, Florida and inserting Pensacola and Perdido Bays, Florida; and Mississippi Sound, Mississippi; and (2) in subsection (i)(1), in the matter preceding subparagraph (A), by striking 2026 and inserting 2031.

With respect to the amendment made by section 2(1), the Administrator of the Environmental Protection Agency may not use for the implementation of that amendment, including, with respect to Mississippi Sound, Mississippi, convening a management conference, developing or carrying out a comprehensive conservation and management plan, or providing grants under section 320 of the Federal Water Pollution Control Act (33 U.S.C. 1330U.S. Code — Title 33, Section 1330View official source on GovInfo)— (1) any amounts appropriated to carry out the national estuary program under that section for fiscal year 2025; or (2) unless the total amount appropriated to carry out that program for fiscal year 2026 is at least $850,000 more than the total amount appropriated to carry out that program for fiscal year 2024, any amounts appropriated to carry out that program for fiscal year 2026.