PLYMOUTH — Alewives and blue-back herring have been fighting a losing battle to get to Billington Sea to spawn each spring since dams along the Town Brook were built to support a flourishing industrial age in Plymouth.
But with the $750,000 presented to the town by the state Department of Conservation and Recreation Wednesday, that journey should become easier. The money will help remove the Off Billington Street Dam, a major obstacle to spawning fish for more than two centuries.
Standing at the podium near the dilapidated dam Wednesday, Plymouth’s environmental manager, David Gould, said work should be underway by next summer.
“Come back here next year when it’s all done, and it will blow you away,” Gould said.
The project calls for removal of the dam as well as thousands of cubic yards of sediment, laced with contaminants from past industrial endeavors. The natural stream channel will be reestablished and adjacent wetlands restored.
Final steps include construction of a bridge and significant water, sewer, and storm-water management improvements.
Town Brook is well known in history for its importance to the Pilgrims, when they landed in Plymouth in 1620. The 1.5-mile stream, which courses to Plymouth Harbor from a 269-acre pond the Colonists dubbed Billington Sea, supplied the travel-weary band with a source of fresh water.
Popular history has it that, in the spring of 1621, the Native American Squanto taught the starving Pilgrim survivors how to fertilize crops with herring, snared from the brook as they journeyed by the thousands to spawn in Billington Sea.
The Colonists soon discovered other uses for Town Brook. Over the ensuing centuries, six dams were built to power a variety of industries, from corn mills and forges to wool, leather, nail, and snuff mills.
The dams helped industry but damaged the ecology of the area. Water stagnated in mill ponds, becoming unnaturally warm and depleted of oxygen. Sediment, laden with contaminants from the mills, built up, and weeds choked the man-made pools. Cold water species that had previously flourished in Town Brook gradually disappeared.
Work to restore the natural ecological balance to Town Brook began about 15 years ago. One dam was completely removed, and two others lowered. More efficient fish ladders replaced primitive models at Jenny Grist Mill and the Newfield Street Dam.
Gould said the town, assisted by the state Division of Marine Fisheries, has provided a little help for the last several years to herring as they struggled upriver to spawn.
“We net them below Jenny Grist Mill or at the Newfield Street dam, put them in a tank, and truck them to Billington Sea,” Gould said.
The Off Billington Street Dam and the nearby Plymco Dam, two major obstacles to spawning fish in Town River, have been the subject of a joint study that began in 2007. Once work is complete on the Off Billington Street Dam, demolition work will begin on Plymco, Gould said before the presentation.
“We have 90 percent of the design and permitting for Plymco Dam done,” Gould said.
Eric Hutchins, a biologist with the National Oceanic and Atmospheric Administration’s Northeast regional office, was not present Wednesday but has been involved in the Town Brook restoration for nearly 15 years. With the removal of the Off Billingston Street and Plymco dams, “the fish will have the reasonable ability to migrate themselves to Billington Sea,” Hutchins said in an interview.
“This will be the most free access they’ve had for easily 200 years.”
Hutchins said Town Brook’s herring counts have remained at about 140,000 for the last four years. “We believe the potential is to double or maybe even triple that once they have free passage to Billington Sea,” he said.
The total cost of the Off Billington Street project is about $1.2 million, Gould said. The town has chipped in about $250,000, and funding from the National Oceanic and Atmospheric Administration and American Rivers, through its River Restoration Program, will supplement the state’s $750,000 contribution.
Brian Graber, the northeast region director of the American Rivers’ restoration program, cited the importance of the Off Billington Street and Plymco dam demolition projects, saying the pair block nearly all herring from reaching Billington Sea.
“There’s nothing worse you can do to a river than put a dam on it, and nothing will restore it faster than to remove a dam,” he said.