West Tisbury residents heard from proponents of three distinct futures for the Mill Pond at a standing room only information meeting selectmen hosted at the Howes House Wednesday.
In front of an audience of about 100 people, dredge committee chairman Bob Woodruff, civil engineer Kent Healy, and landscaper Prudy Burt described the different possibilities for the 2.5-acre pond at the entrance of town, next to the police station.
Mr. Woodruff favors a plan to dredge the pond and increase the average depth from around two to four feet. Selectmen appointed Mr. Woodruff chairman of the Mill Pond committee in 2008.
Mr. Healy, a member of the Mill Pond committee, presented a plan to maintain the pond using much simpler and less costly measures, such as pulling weeds.
Last up was Ms. Burt, a member of the town’s conservation commission, who spoke as a private citizen. She presented a plan to remove the Mill Pond dam and restore as much of the natural connectivity as possibility upstream from the pond along Mill Brook.
Experts from the Nature Conservancy of Massachusetts, a river restoration scientist, and an environmental consultant also spoke in support of removing the dam.
Proponents were allowed 30 minutes each to make their presentation. No votes were taken or decisions made.
Dredge to preserve
Mr. Woodruff spoke about the pond’s historic, ecological, and cultural significance to the town. He said there is evidence the pond is shrinking and in danger of drying up because of silting and vegetation.
He said the best way to preserve the pond is to dredge it.
“I think there is a lot of fear, mystery and concern about dredging,” he said. “It’s like a four letter word or something.”
Mr. Woodruff said the Mill Pond provides an important habitat for several species, including otter, Canada geese, green-winged teal, and kingfishers, to name a few.
Mr. Woodruff said the pond could, in a pinch, serve as a fire pond. The town fire department usually uses Maley’s Pond, but the Mill Pond could also work in an emergency, he said.
He also said the pond held a special place in the community, as evidenced by the fact that the image of the old gristmill at the pond’s edge has been used as the town seal.
Mr. Woodruff cited a 2008 study by Aquatic Control Technology (ACT) that concluded that vegetation will continue to degrade water quality, impact the pond’s wildlife, and contribute to the filling of the pond.
“The bottom line [of that study] is: dredge the pond if you want to preserve it,” he said.
He also cited a study completed by Environmental Engineering Service (ESS) last year that laid out three options for dredging the pond that cost between $240,000 and $700,000.
Mr. Woodruff said his committee has settled on the least costly of the dredge plans, to remove 3,150 cubic yards and increase the average depth of the pond from 1.7 feet to four feet.
He said the dredge work would cost between $150,000 and $200,000. “We think that is very basic,” he said.
Steven Ewing, a marine contractor and dredge operator for the Edgartown Great Pond Foundation, wrapped up the first segment, saying the Mill Pond committee has talked to him about managing the dredge. He outlined past projects he was involved with and explained the type of dredge machine that would be used.
Not getting shallower
Next up was Mr. Healy, who despite being a member of the Mill Pond committee holds the minority opinion that the pond does not need to be dredged.
Mr. Healy said he has been measuring the flow in the Mill Brook for 20 years, and the depth of Mill Pond varies from year to year depending on factors like the amount of rainfall.
Mr. Healy said Mill Pond was never historically more than an average of two feet deep
“Preservation of the pond depends on understanding and controlling water flow into and out of the Pond,” he said. “Mill Brook water has been sampled and tested and it has kept remarkably clean.”
Mr. Healy said the data compiled by ACT in 2006 and ESS in 2011 shows the depth of the pond has increased in certain areas.
“The change in depth by those two firms indicate that the pond has shallowed along the west side but is deeper by about a foot in the center,” he said.
Mr. Healy also said images from Google Earth from 1995 to now do not show any significant reduction of the area of the pond.
“It’s not getting smaller, it’s not getting shallower,” he said. “The Mill Pond dam is in good condition and as its new owner, the town of West Tisbury can keep it that way.”
If you removed the boards to drain the pond, Mr. Healy said, you could put the boards back in and the pond would fill back up in about eight hours. “It’s a shallow widening of the [Mill Brook],” he said.
Last up was Ms. Burt, who described the Mill Brook as a series of independent water bodies cut off from one another by dams and spillways.
“What we have on Mill Brook is a very segmented system, with fish and wildlife at risk,” she said.
Ms. Burt said communities across the state are now pursuing stream or river restoration projects that involve dam removal.
“I think we are lucky to be able to have it. How many towns get to make a choice that has an immediate ecological benefit and immediate financial benefit to the town?” she said.
Ms. Burt then turned the discussion over to Alison Bowden, director of the Nature Conservancy’s Freshwater Program in Massachusetts, and an aquatic ecologist specializing in migratory fish.
Ms. Bowden said there are more than 3,000 dams across the state, many of which are mill dams that no longer serve a functional purpose because, “the mills aren’t here anymore.”
Free-flowing streams have higher dissolved oxygen rates and generally have cooler waters preferable for certain species of wildlife. They also tend not to accumulate pollutants, Ms. Bowden said.
“Our basic goal…is ecological integrity, the capacity of an ecosystem to sustain itself and stand up to stresses,” she said. “We want the system to be able to take care of itself and be healthy.”
She also said all aquatic species need connectivity to some degree to meet their life cycle requirements.
Beth Lambert, a river restoration scientist for the Mass Division of Ecological restoration, showed photos of waterways around the state before and after dams were removed.
Ms. Lambert said most ecosystems generally “green up” and return to their natural state fairly quickly after dams are removed.
“There is a common perception that if a dam has been there a long time the riverine environment can’t return, but that’s not the case,” she said. “We see that the fish return often in the first season.”
She said towns chose to remove dams for a number of reasons, including infrastructure concerns, liability concerns, pond silting, interest from citizens, and restoring connectivity for wildlife.
“In a number of instances…people are asking: Why are we repairing this piece of infrastructure when we could remove it and save money in the long-term?” Ms. Lambert said
Ms. Lambert said there are grant programs that will pay for a majority of dam removal projects. “The dam owner usually ends up paying 10 to 20 percent,” she said.
Q and A
During the question and answer period that followed, residents asked a wide range of questions regarding the different proposals.
Victoria Danberg, a seasonal Edgartown resident and an alderman in Newton, asked if removing the dam would threaten the Garden Club building on the other side of Edgartown-West Tisbury Road.
Mal Jones of West Tisbury said removing the dam might be futile because beavers might just come in and dam it up again.
One audience member asked if removing the dam would have any effect on the other ponds upstream, or create any problems with flooding downstream.
Bill Roman of West Tisbury said removing the dam would benefit some species but potentially harm others.
“How do you assess the tradeoff of one ecosystem for another? The pond supports fish, birds and other types of wildlife, and a stream would support another,” he said.
After more than two hours, selectman Richard Knabel brought the meeting to a close, although it was obvious the discussion could have continued.
Correction: An earlier version of this story incorrectly reported that Bill Roman lived in Oak Bluffs.