Today is the 40th anniversary of the Clean Water Act, federal legislation that has improved quality of life for millions of Americans, increasing recreational opportunities, improving public health, adding to our aesthetic enjoyment of nature and our environment, and providing business opportunities to manufacturers of boats and fishing equipment, rafting outfitters, and retailers of outdoor equipment. The Act is proof of the power and benefits of federal regulation; it transformed our world in so many visible ways and did more to protect our precious water resources than any other action, public or private, in the nation’s history.

It’s hard for young people to imagine just how polluted and threatened our waters were in 1972, when the Act was passed and signed into law by President Richard Nixon. I grew up near Detroit, on the shores of Lake St. Clair, the lake that, along with the Detroit River, connects Lake Erie and Lake Huron. After heavy rains, tides of human sewage and fecal matter would flow out into the lake, and continuous discharges of mercury and other toxins from industrial plants killed all but the hardiest and least appetizing fish. I swam in that lake throughout my childhood and paid for it every summer with earaches and infections.

Today, the stinky brownish green waters have been transformed into sparkling aquamarine, and Lake St. Clair is a boater’s heaven, with powerboats, kayaks, and sailboats cutting through the water in all directions. The sport fish population has been restored, and the worst threat is that zebra mussels have filtered too many microorganisms out of the water.

In 1979, I moved to Washington, whose major river, the Potomac, was a toxic soup of agricultural fertilizers and industrial waste that ran brown with sewage after every heavy rainstorm, killing fish by the thousands and discouraging spawning runs by migratory fish that had been made for thousands and thousands of years.

The Potomac still has problems, but a river that was scary to fall into 40 years ago now provides fabulous fishing for migratory shad, rockfish, largemouth and smallmouth bass, and much more. Amazingly, one of the top bass tournaments in the country takes place right here. I swim in the Potomac, my daughter rowed on her high school team, and all through the summer people windsurf and paddle out of the Thompson Boat Center near the Kennedy Center. It’s a remarkable rebirth of a great river.

But we got a painful reminder of how fragile the recovery is 10 years ago when a small business in Silver Spring, Md., dumped a potent pesticide into a storm drain and killed 150,000 fish and most aquatic life for eight miles down Rock Creek, in the heart of Washington. The fight to preserve our rivers and natural resources can never let up. Do we have too much regulation? Does reducing pollution of the Potomac or Lake St. Clair threaten small business? Not a bit.

We should all be grateful that 40 years ago, President Nixon and Congress had the vision and the faith in government to pass the Clean Water Act and start the long process of restoring our public waters and preserving a key resource. We still have a long way to go, but we can get there if we can resist the lobbying of those whose self-interest lies in polluting and degrading the nation’s lakes and rivers.