Casco Bay not only provides a beautiful backdrop for residents of Portland and many nearby coastal towns, but is also responsible for the allure that draws so many visitors to the region. What’s more, Casco Bay, along with other waterways in the area, such as Sebago Lake, supports dozens upon dozens of small businesses that give Maine residents and visitors opportunities to use and explore the state’s lakes, rivers, wetlands and coastal waters.

Portland Paddle, for example, is a local business that depends entirely upon the health of Casco Bay and the multitudes of rivers and streams that feed into the bay. The business offers sea kayaking trips, lessons and rentals for many thousands of locals and out-of-towners each summer and employs a half-dozen full-time seasonal staff, including several Maine guides. Its business model wouldn’t be possible without an ecologically robust bay.

Not long ago, however, the waters surrounding Portland were not nearly so appealing for paddlers. The Presumpscot River and other waterways flowed into the bay thick with raw sewage, paper mill effluent and other pollutants. But the Clean Water Act of 1972 helped transform Casco Bay into what it is today: An environment that’s ideal for sea kayaking — and for sustaining countless businesses like Portland Paddle that rely on its vitality.

We should be doing everything we can to further protect our waterways and make sure Casco Bay remains at least as healthy as it is today. But far too many of the streams and wetlands that flow into Casco Bay, along with more than half (55 percent) of the streams that crisscross our state, did not have guaranteed protections under the Clean Water Act until very recently. That means developers could build over our wetlands; oil companies, power plants or meat processing plants could dump into our streams; and federal law couldn’t stop them, thanks to a loophole created by a pair of polluter-driven lawsuits nearly a decade ago.

The loophole left vulnerable the wetlands and streams that feed into Casco Bay, Sebago Lake and other rivers and lakes popular for paddling and swimming; and that leaves local businesses like Portland Paddle more vulnerable, too.

Fortunately, on Aug. 28, the U.S. Environmental Protection Agency enacted a rule to close this loophole and restore protections to nearly 25,000 miles of streams across Maine, and nearly 2 million across the country.

A broad coalition of clean water advocates, farmers, mayors, small businesses and thousands of Mainers have heralded the EPA move. However, agribusinesses, oil and gas companies, and other polluters affected by the rule have waged a bitter campaign against it and are continuing their fight this fall to block the new rule.

In the face of all the opposition from the polluters, it’s critical that all Mainers who value clean water make their voices heard. This fall, we’ll need Sen. Angus King to continue his environmental support so that all of Maine’s lakes and streams remain protected by the Clean Water Act.

Mainers depend on clean water not only to enjoy but also to drink. Businesses like Portland Paddle depend on clean water to make a living. Let’s do everything we can to foster a good economy and a high quality of life for generations to come.

Caleb Greenawalt is a campaign organizer with Environment Maine. Zack Anchors is a Maine native and the owner and Master Maine Guide of Portland Paddle.