Every year since 1988, on the second Sunday in June, Bernie Fowler has been wading into the Patuxent River, stopping when he can no longer see his white sneakers.

This year, on the 25th anniversary of the wade-in, he got up to 35 inches. As the Sneaker Index measurements go, it wasn't bad. But it is a far cry from the 1950s, when Fowler said fishermen could see crabs scurrying across the bottom 12 feet down, and minnows darting in and out of thick oyster beds. And it pales in comparison even to 1994, when the Bay grasses in the river were so tall that children pulled them up to make wigs.

The decent sneaker index comes on the heels of the Patuxent River's worst river health grade yet. According to the University of Maryland Center for Environmental Science's annual river report card, the Patuxent scored an F on account of its poor water clarity, scarce underwater grasses and low dissolved oxygen.

"That kind of crushes me, and makes me sad," Fowler said. "When we could have cleaned it up, and we had the money at the federal and state level to do it, we were taking baby steps."

At one time, cleaning up the Patuxent seemed not only possible, but even probable to Fowler. Nearly 40 years ago, when he was a Calvert County commissioner, Fowler and the leaders of Charles and St. Mary's counties sued the EPA. The agency was going to allow the fast-growing upstream counties to discharge millions of gallons of sewage into the Patuxent River. The University of Maryland scientists in Solomons Island came to court with hard evidence to buttress Fowler's eyewitness reports.

The counties won, and the state agreed to reduce the allowable levels of nitrogen and phosphorus flowing into the river. That agreement became the model for interstate cooperation, which eventually led to the multi-agency Chesapeake Bay Program and its multi-state restoration effort. The university scientists were so grateful for his contributions to the river that they renamed their laboratory in his honor. And today, more than a dozen communities in Maryland have started wade-ins of their own to gauge the health of their rivers and engage the public.

The 1980s were a hopeful decade for the Patuxent. Fowler took his fight to save the river to Annapolis, where he served as senator from 1983 to 1994. There, he encountered a sympathetic governor in Harry Hughes, who promised Fowler resources and support. Perhaps most significantly, Fowler managed to pass a bill that forbade any of the wastewater plants in Calvert County from discharging effluent into the Patuxent. They instead do land application.

At the 1997 wade-in, Fowler waded out to a depth of 44.5 inches. It was the test's high water mark, and it showed that the sewage-treatment improvements upstream were working.

But over the next decade, Calvert County became one of the fastest-growing areas in Maryland, and its roads became congested with commuters heading to the Patuxent River Naval Air Station and Washington, DC.

Upstream areas in Prince George's and Howard counties were growing quickly as well. In the 1980s, when Fowler started his push for the Patuxent, the watershed had a population of 100,000. Today, it is seven times that. Just by itself, Columbia, MD — a watershed town created in 1967 — has as many people as the whole watershed had then.

"Growth is the killer. There's no question about it," Fowler said.

Fowler was thrilled that Gov. Martin O'Malley came to the wade-in and proclaimed June 10 "Bernie Fowler Day," and also that U.S. Rep. Steny Hoyer gave him an American flag. But he let them both know he's unhappy with the current pollution diet, which allows as much nitrogen to enter the river in 2020 as it does in 2010 — too much, considering the river's recent health.

Now 88, Fowler still has the energy of a much younger man. A competitive runner, he shows no signs of stopping. But he moved the wade-in from Broomes Island, where he grew up and began his activism, to the grounds of the state-run Jefferson-Patterson Park and Museum — acknowledging that he may need someone else to organize and promote it in the future. And he admits the uphill slog can be discouraging, especially when citizens are no longer storming the halls in Annapolis and Harrisburg to demand clean water and the local and state governments say they have no money for cleanups.

"I don't have the enthusiasm and optimism that I had," Fowler said, "but for the generations that follow us, it would be real cowardice to back off and say, 'it's not going to work.' I'm going to continue."