THE TRUMP administration’s mindless attempt to scrap federal funding to clean up the Chesapeake Bay is a stroll down memory-impaired lane. Heedless of recent history, the administration’s proposed budget would, at a swipe, reopen the door to the degradation of the United States’ largest estuary and reverse important recent progress in restoring the water, fish, oysters, crabs and tourism that make the bay so vibrant.

It was just six years ago that a third of the bay, from Baltimore to the Potomac River, was beset by a sprawling springtime “dead zone” of oxygen-starved water — the result of marine-life-killing nutrients from fertilizer and other chemical runoff. In the quarter century or so before the Environmental Protection Agency launched a massive cleanup program in 2010, the oyster harvest had plummeted by 96 percent and the crab harvest by 60 percent. Starved for oxygen by runoff pollution, huge tracts of the Chesapeake’s 64,000-square-mile watershed were in a death spiral.

When the EPA intervened with what amounted to a tough “pollution diet” for the bay, it represented the last, best hope to revive an American treasure. The 15-year cleanup effort imposed a mandate on the District and the bay’s six watershed states — Maryland, Virginia, West Virginia, Pennsylvania, Delaware and New York — to make sharp reductions in the levels of nitrogen, phosphorus and sediment that starved the bay of oxygen and were killing off recreation and industry alike.

Now, by zeroing out the EPA’s planned $73 million for the cleanup next year, the administration’s budget would mark a pollution binge even as the pollution diet’s manifest benefits were working to revive a body of water that was becoming a lifeless soup.

Some industrial farms, home builders and municipalities have resisted the EPA cleanup, regarding it as bureaucratic overreach. They have said it amounts to an unfunded mandate saddling them with the costs of cattle fencing and other means of pollution mitigation. From beyond the watershed, opponents feared it would become a template for even more ambitious actions by the EPA, including an effort to clean up the Mississippi watershed that might be expensive for major industrial polluters.

Those interests prevailed in the administration’s budget, which would hinder efforts to upgrade sewage treatment plants with new technology and develop tighter standards to control storm water in both urban and suburban neighborhoods. But make no mistake: If the EPA program dies, so will the bay, and a precious natural resource will be despoiled for future generations.

A sign of hope is the vigor of the pushback already being mounted by the region’s congressional delegation, including a number of Republicans. Maryland Gov. Larry Hogan, himself a Republican, has not directly attacked the effort to gut the cleanup program, but his spokesman issued a forceful statement on his commitment to revive the bay. It will take a concerted political effort and public pressure to recover the funds eliminated in the administration’s proposed budget. It is critical that they succeed.