Removing Head Tide dam to improve fish passage won’t be an easy sell, if questions and concerns expressed at the Alna public informational meeting Tuesday evening are an indicator.
A professional assessment argues high flows through openings in the 90-year-old barrier impede the passage of alewives, Atlantic salmon, and shad during spring migration up the Sheepscot River.
Resident and longtime fisherman Peter Christine said, “I hear the assumption (that removal) will improve passage, but I don’t see the evidence. The dam has been there during tremendous fish runs.”
Also important to some of the approximately two dozen townspeople in attendance was the possible impact on the traditional swimming hole. Many people enjoy the spot on the dam’s downstream side in summer. Would it still be there with the dam gone?
Mike Chelminski of Stantec Consulting, Topsham, said deeper knowledge of river hydraulics and sediments behind the dam would be necessary to answer the question.
The Sheepscot River Watershed Council’s coordinator, Charlie Baeder, headed a barrier survey of the watershed last summer. He then approached Alna selectmen about ways to improve passage, possibly by enlarging the existing openings in the dam.
The council’s concern was largely for shad, described by a fish biologist as an important angling species; it is “skittish” and can easily be deterred if water velocity is great. Impeded to a lesser degree are alewives, a type of river herring, commercially useful as bait; and Atlantic salmon, which are on the federal endangered species list.
Other species present in the river and important to its ecology are lampreys, American eels, striped bass, and smelts.
Chelminski said the two portals on the east and west ends of the dam allow “marginal passage at best during spring migration.” Flow speeds of less than six feet/second are preferable.
Making the openings bigger could prove hazardous to the structure’s stability. The openings also catch debris, including beaver dams, and have to be cleaned out annually. At one time the state Dept. of Inland Fisheries and Wildlife brought in equipment to do the job, according to the current alewife harvester.
“So what will help?” the consultant said. “Take a Sawzall all around the dam and get it out of the picture.”
Local sentiment about the dam and its longstanding presence in the community complicates the option.
Christine pointed out that Atlantic salmon “are a fall run fish.” The heavy flows Chelminski identified as occurring between April 15 and June 15 do not coincide with their upstream migration. As for alewives, Christine said the fish are at the dam, where the dipper is ready to harvest them, long after the flows subside.
Chelminski agreed salmon “have less of a problem getting up, especially if they’re pushing in in late summer, early fall. They’re terrific swimmers.” Alewives, he said, pile up downriver if they can’t pass the dam.
Views on the presence of shad varied. David Sutter, of Wiscasset, who has alewife harvesting rights on the Sheepscot, said in 20 years of dipping alewives, “I caught one shad, at Coopers Mills.”
Christine Lipsky, a fish biologist with the National Oceanic and Atmospheric Administration (NOAA), has trapped salmon smolts at the dam for several years. “We’ve had problems with dead shad washing into our traps. In my professional opinion, they’re falling into the traps because they’re having trouble passing.”
Chelminski commented that having more of the river available to shad “could make a big difference in their resurgence.”
A listener protested that there are “no counters of fish going up” and that all the information is “anecdotal.” He said, “You can’t have data based on anecdote.”
Mabel O’Brien expressed concern about erosion of riverfront land below the dam if the structure is removed. There was also a question about the impact of recreational paddlers on landowners below Head Tide because, with the dam removed, kayakers and canoeists would continue downstream and take out at Puddledock.
Linda Bean wanted to know who would pay for dam removal and where the money would come from “in these tough economic times.”
Chelminski said, “For better or worse there’s a big pot of money available for dam removal. We know there’s a lot of money spent at the Maine and federal level on salmon,” which is a favorite sport fish. “The envelope is empty for rebuilding dams. It’s hard to show the benefit.”
To Bean’s suggestion to shave off just the top of the dam, leaving the rest intact, Lipsky wondered if that option “would qualify for federal money.”
Chelminski pointed out the dam presents liability issues and that government agencies are willing to help the town get rid of what is essentially “a nuisance structure.” He added, “Admittedly, fish are getting through,” but do residents want to retain a liability? Why not “get the junker out of the driveway?” he asked.
Engineer Matt Bernier, who estimated removal would cost about $200,000, reminded the assembly that owners of dams on rivers with an endangered species “have a responsibility to provide safe passage for that species. It’s a serious issue. The regulatory screws get tightened” if passage is inadequate, and the numbers of fish that fail to migrate are considered a “take.” “That’s when the heavy hand of government comes in,” he said.
Christine cautioned, “Before we scare the town, let’s first establish that this dam is an obstacle to passage.” He said salmon populations “dropped off in 1985 when there was a great warming in the Gulf of Maine and over-harvesting of alewives.”
David Jewett raised concerns about late winter ice jams. “The dam does a good job of breaking up ice as it goes down river,” he said.
Chelminski replied that Jewett posed “a good question” and on another project his company worked on, “we had the Army Corps of Engineers do an analysis.”
There will be a follow-up meeting in several months. Baeder invited people with questions to email him at srwc@fairpoint.net. He said he will later post questions and answers on the council website www.sheepscot.net.
