; (B) to restore and recover species that are— (i) endangered; (ii) threatened; or (iii) at risk; and (C) to prevent significantly harmful adverse impacts to the Chattahoochee River and Apalachicola River ecosystems. (3) Secretary The term Secretary means the Secretary of the Army. (b) Project modification Notwithstanding any authorized purpose of the Apalachicola-Chattahoochee-Flint projects, the Secretary shall operate the Apalachicola-Chattahoochee-Flint projects in a manner that ensures the maintenance of freshwater flows. (c) Freshwater flows study (1) In general Not later than 30 days after the date of enactment of this Act, the Secretary shall enter into an arrangement with the Administrator of the National Oceanic and Atmospheric Administration under which the Administrator shall conduct a study that— (A) evaluates existing studies, assessments, and data related to freshwater flows; and (B) provides recommendations on how to maintain freshwater flows. (2) Completion date The study referred to in paragraph (1) shall be completed by not later than 1 year after the date of enactment of this Act. (d) Revision of water control manuals (1) In general The Secretary— (A) shall not issue a final water control manual based on the final environmental impact statement of the Secretary entitled Update of the Water Control Manual for the Apalachicola-Chattahoochee-Flint River Basin in Alabama, Florida, and Georgia and a Water Supply Storage Assessment and dated December 2016