WILTON — Comstock Brook is probably not as well known around town as the Norwalk River, but Jeff Yates of Trout Unlimited calls it “one of the last, best places” in an area so close to New York City. He and many others don’t want to lose the brook to development, pollution or other threats.

To bring people up to speed on why preserving Comstock Brook is as important to humans as it is to the flora, fish and other animals that depend on it, there will be a Zoom program called “Comstock Brook: Protecting & Restoring Our Native Brook Trout Stream,” on Aug. 18, from 7 to 8:30 p.m.

It is presented by Wilton Library, Trout Unlimited, the Norwalk River Watershed Association, and the Wilton Land Conservation Trust. Register online to receive the Zoom link.

The program on Comstock Brook is the first of a two-part series that concludes Aug. 31, 7 to 8:30 p.m., with “Bee” The Change: Protect Wilton’s Rivers by Joining the Pollinator Pathway. Register online.

“Probably the most important thing to understand is Comstock Brook is one of the few remaining streams in lower Fairfield County that is home to native brook trout,” Yates said. While rainbow and brown trout can also be caught here, they are not native to New England.

The brook trout, Yates said, is the canary in the coal mine when it comes to protecting the inland watershed. They require the coldest, cleanest water to survive.

“You don’t see them in other streams is because of the degraded water quality from industry and climate change,” he said.

Comstock Brook has its source in Ridgefield and it and its tributaries flow through Quarry Head State Park, Millstone Farm, across Nod Hill and Middlebrook Farm roads and empties into the Norwalk River at Merwin Meadows.

Above Nod Hill, the brook is cold and clear, babbling its way south, but then at Merwin Meadows it dries up spring, summer and fall and never reaches the Norwalk as surface water. That’s because a dam diverts water to the reservoir along Old Huckleberry Hill Road, owned by South Norwalk Electric & Water.

“A river should get bigger as it flows downhill, but because of drinking demands, it is dry for the last mile,” Yates said of Comstock Brook. “It is disconnected from the Sound.”

The goal of the program on Tuesday is to “start building awareness and community support for Comstock Brook because the things we can do to protect it, the Norwalk River and Long Island Sound — it’s going to take a shared commitment, years and decades of effort on all our parts. If we don’t start that effort now … we probably won’t have another chance,” Yates said.

The three Ds

He called the major threats to Comstock Brook the three Ds: dams, development and degradation.

Dams prevent the migration of fish up and down the inland waterways to and from the Sound. “We’ve cut these rivers off from the Sound for years,” Yates said. “Life can come back in big ways.”

Development is a threat because even land that doesn’t border a waterway has an impact on it. When it rains, the water washes pesticides and herbicides from residential properties and storm water, sand and road salt from roads. The more roads, driveways and parking lots there are, the more polluted, and in summer, hot water there is that flows into the rivers and makes its way to the Sound. Private wells, like thousands of tiny straws, draw water from the underground aquifers that otherwise would feed these rivers and streams.

Degradation results from climate change that brings heavier and bigger storms to our area, and invasive species that kill the mature forest canopy and replace it with less beneficial flora.

Loss of open space

People may not be aware, Yates said, that South Norwalk Electric & Water is a private company and the hundreds of acres it owns through which Comstock Brook flows are not protected as permanent open space. If a larger company were to acquire SNEW, and did not need the brook for its water supply, it could sell that land for private development.

“We need to find a way to work with the water company, the state, the land trust and others to permanently protect land as open space,” Yates said.

What can be done

There are steps people can take to protect Comstock Brook and other inland waterways.

One is to support organizations like Wilton Land Conservation Trust, Norwalk River Watershed Association, Save the Sound, and Trout Unlimited. “We need more time and money to keep our efforts going,” Yates said.

He also encourages people to support purchases of open space in Wilton and Ridgefield. It is far less expensive, he said, to protect resources before development than afterwards.

Yates would also encourage people to join the Pollinator Pathway and plant native species, reduce the size of their lawns and reduce the use of pesticides and fertilizers.

Finally, he encourages people to join the conversation by tuning in to the program.

“We know the people in our community care about the outdoors and the environment,” Yates said. “We can build a groundswell of support to protect the Comstock Brook, Norwalk River and the estuary.

“We have this unique moment to drive a lot of positive change. It’s not too late to save this brook and improve the watershed.”

Anyone interested in volunteering can contact Trout Unlimited: Jeff Yates at Jeffrey.Yates@tu.org; Wilton Conservation Land Trust: David McCarthy at david.mccarthy@yale.edu; Norwalk River Watershed Association: Louise Washer at lbwasher@gmail.com; Save the Sound: info@savethesound.org.