By Thane Grauel

WESTPORT — A dam on Sasco Brook, built beside an old mill more than a century ago, is coming down.

Its construction on the Westport-Fairfield town line by the Post Road created freshwater Bulkley Pond. Its elimination will allow several species of fish to navigate upstream from Sasco Creek, as the waterway is known below the dam, for the first time in generations.

Among those are alewives, blueback herring and American eels.

The eels — born thousands of miles away in the Atlantic’s salty Sargasso Sea, but who live much of their lives in fresh water — might already have returned.

Westport Conservation Director Alicia Mozian said the dam is the first obstruction on the waterway heading upstream from Long Island Sound at Southport Beach. The dam had been the dividing line between salty, tidal water and fresh water.

The species of fish that will benefit from its removal need both kinds of water with different seasons or stages of their lives.

“This is a good thing,” Mozian said. “It alters the landscape quite a bit, taking away a dam that has been there probably almost 200 years.”

She said the dam was breached by a major storm about four years ago, so the process of returning the brook to its natural state already was under way. The dam’s removal accelerates that.

“It’s going from a pond to basically a wet meadow,” she said. “When the dam was breached, the native seeds embedded in the mud were able to reemerge on their own, and this is beautiful.”

She also talked with someone a few days ago who reported already seeing eels in the shallow pond.

“Herons and deer, the wild turtles,” she said. “The wildlife seems to be enjoying their new habitat.”

David Brant, executive director of the Aspetuck Land Trust, the organization that spearheaded the dam’s removal and obtained grants from the National Fish and Wildlife Foundation and state Department of Energy and Environmental Protection, also was glad to the see the dam finally coming down.

The land trust was established in Westport in 1966, and now has 175 properties in seven towns. It owns much of Bulkley Pond, and a tract of land along it known as Peter’s Gate.

Brant was excited to hear of the eel sighting, and about what’s now possible for other species.

“These fish are now going to be able to go up to the fresh water and spawn,” he said. “When you have more of these fish, you have more birds because you increase the food source.”

On Friday morning, as heavy machinery plucked old blocks of stone out of the waterway, a great blue heron took flight and circled over the pond.

Brant said the land trust worked with Sally Harold, who worked for years with the Nature Conservancy and is now an expert consultant on dam removal projects.

“We’ve dammed up all these rivers, but it’s really fascinating when you get under the hood with this stuff,” Brant said. “There are a lot of private dams on these rivers and they’re preventing the migrations from happening.”

Mozian said the work is expected to be complete by Monday.

Thane Grauel, the Westport Journal executive editor, grew up in Westport and has been a journalist in Fairfield County and beyond more than three decades. Learn more about us here.