Rebuilding the walls, which date to the late 1800s and early 1900s, would better protect areas along the Potomac River and Tidal Basin against water-level rise and storm surge.
States say Federal Energy Regulatory Commission did not consider New Jersey's claims that added capacity was not needed and would violate its climate change law.
State DOT dumps stalled $7.3B private developer approach of previous administration, but with public funding not in hand, design and construction is years away.
Nearly 20 years after beginning construction and $1.23 billion later, the U.S. Army Corps of Engineers' Charleroi Lock and Dam in Monessen, Pa., is scheduled to be completed later this year.