Fifity-year-old aboiteau at Windsor causeway Photo: Darren Porter

The Mi’kmaq call the Avon River “Tooetunook,” which means “flowing square into the sea,” or more specifically, into the Minas Basin in the upper Bay of Fundy.

Since 1970, when the Windsor causeway was constructed across the Avon, the river hasn’t exactly been able to “flow square” at all. That’s because the aboiteau — the tidal gate at the causeway — has restricted tidal flow in the river.

It’s not a large structure, but the aboiteau that divides the Avon into freshwater river and tidal estuary is causing an over-sized rift in Hants County.

On one side, literally, are those determined that the aboiteau should restrict water flow in the Avon enough to maintain fresh water levels in the artificial reservoir, Lake Pisiquid, that is upstream from the causeway, and also protect it and more than 3,000 acres of agricultural land from turbulent, salt water gushing up the Avon River from the Minas Basin during high tides.

Avon River upstream and downstream from Windsor causeway Google Maps

According to the Avon River Heritage Society, even the name Pisiquid — as the Acadian settlers called the river in the 1700s — has its origins in the Mi’kmaw word that described it, “Pesegitk,” which means “to flow split-wise” or “junction of the waters.” The Avon receives waters from no fewer than five other rivers.

On the other side of the divide over the tidal dam are those concerned about the health of the fish species that depend on free passage in the Avon River to spawn upstream in fresh water. Among them are First Nations, environmental groups, fishermen, and a significant majority of people in the region.

A poll conducted in Hants County in September 2020 for the Mi’kmaw Conservation Group and Oceans North showed that 77% of those surveyed said they supported restoring free passage of fish to the Avon River, and 65% said that maintaining the existing “man-made reservoir (Lake Pisiquid)” should not be “prioritized over Indigenous rights and the need to restore free passage of fish and balance to the ecosystem.”[1]

The same poll, however, found that 54% of respondents felt that maintaining the reservoir was “important” or “very important.”

The divide is also evident online.

A Facebook page called “Together we can save our Lake Pisiquid” was created on June 28, and now has 403 members. However, it is a private group and my request to join, and thus be able to read the posts there, has not been accepted.

There is also a Facebook page started in 2007 called “Save the Avon River,” which is a public group with 900 members. One of the administrators of the page, Sonja Elizabeth Wood, who chairs the group called Friends of the Avon River, has struggled for years to have the Avon opened for fish passage. In 2019, Wood, who has been using a wheelchair since a traffic accident in 1985,  travelled to Ottawa in her mobility scooter as a “pilgrimage for Atlantic salmon,” and to protest provincial plans to put in a replacement aboiteau that would not allow full tidal flow and fish passage in Windsor.

Enter provincial and federal governments and politicians, each with different interests and constituencies, and the divide caused by this one small aboiteau turns into a chasm as wide as the Minas Basin and just as deep.

Opening the sluice gates

Although the causeway is half a century old, the current controversy over the operation and the future of the aboiteau really came to the fore when discussions began on the twinning of Highway 101.

Map of highway twinning project area from Stantec EA registration document

In 2017, Nova Scotia Environment approved a project to twin 9.5 kilometres of Highway 101, which involves replacing the causeway and the aboiteau.

The project description submitted to Nova Scotia Environment states that, “The current aboiteau, which is owned and operated by the NSDA [Nova Scotia Department of Agriculture] incorporates two gates (approximately 4.5 m and 6 m) which are automated and monitored by personnel to regulate water levels in Lake Pisiquid.” And:

The causeway and aboiteau act as a dyke and sluice system for agricultural purposes and protect the communities of Windsor and Falmouth from flooding. The aboiteau structure is nearing the end of its design life but will also need to be upgraded to accommodate the highway twinning as well as climate change and fish passage. A portion of Highway 101 at the Avon River causeway, approximately 1,618 ha of protected agricultural marshlands, portions of Windsor and Falmouth, and considerable other public and private infrastructure are already known to be at risk from high storm surges and rising sea levels.

The project description continues:

The causeway has created a freshwater reservoir, known as Lake Pisaquid (aka Pesaquid), which is part of the landscape of the Town of Windsor and is also used for sport and recreational purposes. Ski Martock also uses the lake to draw water for its snowmaking equipment during the winter ski season.

Windsor causeway separating tidal channel of Avon River from its upstream freshwater reservoir Lake Pisiquid (also Pisaquid and Pesaquid)

The replacement structure, however, must “have provisions for fish passage as required by Section 20 of the Fisheries Act and may include automatic as well as mechanical operation of tidal gates.”

The Fisheries Act may make it difficult for the province to continue to protect upstream infrastructure, if that means limiting fish passage, as the project description notes:

Section 20 of the Fisheries Act pertains to watercourse crossing designs and provision of fish passage, regulation designs that provide free passage of fish without harm and maintain a flow of water sufficient to allow the free passage of fish.

So the design and placement of the new aboiteau, says the Environmental Assessment document, has to be developed to accommodate, among other things, “fish passage requirements in consultation with” the federal Department of Fisheries and Oceans (DFO), and “relevant stakeholder interests and concerns related to lake level management.”

Aboiteau at Windsor causeway Photo: Darren Porter Credit: Darren Porter

Here lies the crux of the problem. There seems to no agreement, not between levels of government nor within the community on how — or if — it is possible to ensure free fish passage without opening the sluice gates and letting the tidewater flow, which would spell an end to the freshwater lake.

To say it is a complex, contentious, and confusing political mess would be an understatement.

In the meantime, the uncertainty is causing a great deal of consternation for people on all sides.

Water keepers set up camp

There is perhaps no one closer to the centre of the controversy than Darren Porter, a Bay of Fundy fisherman and a marine researcher, who is also on the Community Liaison Committee for the highway twinning project.

Darren Porter on his boat in the Bay of Fundy. Photo: Joan Baxter

In the spring and summer this year, Porter held a one-man vigil in his fishing boat just outside the aboiteau, doing live Facebook posts bitterly decrying the lack of water flow, and showing his followers — who number more than 4,000 — images of fish kills that he said were caused by the way the aboiteau was being operated.

Fish kill outside aboiteau Photo: Darren Porter

In his posts, Porter alleged that the federal fisheries minister, Bernadette Jordan, was failing to ensure that the Nova Scotia Department of Agriculture, which operates the aboiteau, provided sufficient fish passage. In his view, Jordan was failing to enforce the Fisheries Act, for which she is responsible.

Porter’s posts didn’t go unnoticed.

Nikki-Marie Lloyd had been following the controversy over the blockage of the fish passage for a long time, with growing indignation. Lloyd, a 24-year-old Mi’kmaw woman from Annapolis Valley First Nation, was dismayed by what she was seeing.

In June 2020, she decided to head to the causeway, hoping to attract public and government attention to the issue.

“So I got hold of some people, some friends and family and told them that I wanted to do something,” Lloyd tells the Halifax Examiner. “We went down, and the first day we went there, on June 8, we stood by the highway at the gatehouse with signs.”

Nikki-Marie Lloyd with her son (Contributed)

“And after a couple of days of going down, I decided that I was going to stay there. A couple of friends and a couple of family members didn’t want me to stay there by myself, so they stayed with me. And we just never left.”

At first, Lloyd says, they slept on the ground, next to their fire and beside the river. Then they began bringing tents, and eventually someone donated a shed that became a Treaty Truckhouse.

Lloyd stayed for two months, until she had to return to Annapolis Valley First Nation in Cambridge when the daycare where she works re-opened for the fall.

“There were a few of us that were there 24/7,” she says, including her four-year-old son and several of her relatives. She says people also came from other First Nations communities, such as Sipekne’katik, and that there were also non-Indigenous allies involved in the protest.

Water keepers near Windsor causeway (Contributed)

“There is all the news about what is happening down in Saulnierville,” adds Lloyd, referring to the ugly scenes that erupted after Sipekne’katik First Nation launched its moderate livelihood fishery in St. Mary’s Bay in September, and non-Indigenous commercial were accused of damaging First Nation fishing gear and torching a vehicle, and a lobster pound was burned to the ground. “But down here in Windsor, we have commercial fishermen standing right beside us,” Lloyd says.

Lloyd tells the Examiner that there were good times — and also bad times — at the Truckhouse. On the positive side:

We got to live by a river. We got to see the sunrise and the sunset over the water. And it was beautiful. We got to go swimming. I bought this inflatable boat so me and my son could go out and paddle on the water. It was an amazing experience to be able to teach my son not only about how nature works, but also about our culture.

And the negative:

I think the hardest thing was the racism, which is hard to deal with. You know, you can kind of brush some of that off, but we literally had to sit there and watch our fish struggle and we were literally sitting there watching them die.

Lloyd says the fish die because the aboiteau isn’t open enough to permit sufficient water flow. She explains:

We have the highest tides in the world, which means we also have really low tides. And when they don’t allow what we call a maintenance flow, where they partially open the gates to let some water out, the water [on the outside] is only a few inches thick, and it’s muddy, so it’s almost like soup, and our fish can’t survive that. They get stressed on the really hot days, as the water heats up and they die outside the gates and even several kilometres down the channel.

Lloyd says some of the racism came from some people driving by the site, who taunted the water keepers with racial slurs. But, she says, most of the racism appears online from “politically connected people,” who don’t want to have free tidal flow, which is what the water keepers want, “because that’s what’s best for the fish and for the river.”

On the other side of the aboiteau

What’s best for the fish and the river, however, is not necessarily what’s best for people who benefit from the restricted water flow, including those who depend on the freshwater Lake Pisiquid that exists only because of the aboiteau that protects it from the silty, salty water in the lower reaches of the Avon River, which like all rivers on the Bay of Fundy fills twice a day at high tide.

In September, dozens of those people rallied in Windsor with a parade of vehicles on the road, and in canoes, kayaks and speedboats in Lake Pisiquid, to draw attention to the importance of the freshwater reservoir.

One of those was Victor Oulton, president of the Nova Scotia Federation of Agriculture, who owns a farm upstream from the causeway.

Victor Oulton

Oulton tells the Examiner that if there were free tidal flow, the farmland in the area — between 3,500 and 3,800 acres — would be flooded with every tide. He says the land is used for corn, soybeans, other forage crops such as timothy and alfalfa, some strawberries, and also as pasture.

The only way to prevent flooding would be with a dyking system, says Oulton. “That would be quite an expensive thing to do, and quite a long time period to get it done also.”

Oulton explains that before the causeway was built, all the way up the river there was a system of dykes and aboiteaux on all the little streams that ran into the main river, to prevent flooding. But, he continues:

Since 1970, those have all gone into disarray, and a lot of them have been torn out, because there was no need for them because the causeway was put in there to basically, get away from all of dyking system that was there.

A 1965 feasibility study of the causeway done by the Maritime Marshland Rehabilitation Administration of the Nova Scotia Department of Forestry, noted that the aboiteaux there dated back to the 1700s, when Windsor was settled by the French, and then replaced by English settlers after the expulsion of the Acadians in 1755.[2]

The 1965 study also shows that even before the causeway was built, one of its perceived benefits was to block the Avon:

A tidal dam (causeway) on the Avon River near Windsor, Nova Scotia, would provide better protection with lower annual costs for the agricultural marshlands in the area than the standard dykes and aboiteaux constructed under the Maritime Marshland Rehabilitation Act… A dam with a tidal sluice could protect 3400 acres of marshland that at the present have to be protected by dykes along the river, and by several aboiteaux.

The study referred only cursorily to fish passage allowance, which it said would have to be obtained from the Canada Department of Fisheries.

Oulton says he would like to see a replacement aboiteau that would increase fish passage but still control water flow and maintain fresh water upstream.

“It’s not just to protect the farmland,” he says. “There would be pieces of the town of Windsor that would flood, and through Falmouth.” Oulton says some recent modelling showed the Avon Valley golf course would also flood.

Oulton tells the Examiner it is not true that he and others defending the freshwater bodies upstream from the causeway don’t want fish passage, saying:

Everybody wants fish passage. Just with the way climate is changing now, we have a tremendous opportunity really, if we can preserve that freshwater resource that’s there. Fresh water is drying up all over the world, and they’re trying to protect that more and more and more. We have 3,000 plus acres of farmland that borders along that river that would be ideal for irrigation; there is some irrigation that’s going on now. People are starting to grow more and more valuable crops in this area. So just to have the access to that irrigation water would be tremendous.

Oulton says that a valuable freshwater ecosystem has developed on the banks of the Avon upstream from the aboiteau, with vegetation growing right to the river’s edge, whereas saltwater riverbanks are very unstable because the tide leads to erosion.

“If that fluctuates, the tidal flow and the salt water, that’s going to destroy all that, and the freshwater fish that are there, and the turtle habitat, and muskrats and beavers. People don’t think about that,” says Oulton.

Lake Pisiquid in the balance

Sheldon Hope is Vice Commodore of the Pisiquid Canoe Club, formed in 1975 on the freshwater reservoir created by the causeway. He says increased tidal flow through the existing aboiteau and a replacement structure would cause two problems for the club.

“The first being the turbulence of the water,” he tells the Examiner. “Our sport is a flat-water sport because we are doing Olympic-level spring canoe and kayak.” He explains that the athletes — who number between 100 and 150 at the club — are in “very narrow, relatively unstable boats. So they need flat water.” If there were more tidal exchange, Hope says there would be waves and currents in the lake.

The second problem, according to Hope, is the “sediment load” that would come with increased tidal flow up the river. He explains:

If you’re familiar with the area at all, you’ll see the large marshland that’s developed on the outside of the causeway. That has been created through erosion downstream, based on the tidal cycle. The Minas Basin is constantly eroding its banks and it creates a large sediment load in that water, which is why it’s kind of muddy and brown all the time. So the same thing that’s happened on the outside of the causeway would happen in the lake … in front of our canoe club, we would basically have a salt marsh.

And over time, what it is now lake would basically disappear and we would have a salt marsh in the lake proper. And all you would really maintain is the main channel of the river. So it basically takes away our water source.

Hope adds that free tidal flow would turn the front of the town of Windsor into “mud,” and it would put the Martock ski hill at risk, as it relies on fresh water from the reservoir for its snowmaking.

The Examiner sent two emails to Ski Martock to request an interview, but has had no reply.

Asked how he believes the issue can be resolved, Hope replies:

There’s a lot of scientific information out there about this. A lot of study has been done. And I hope that people follow the science and the right people are doing the talking … People may argue the system is good or bad in terms of what was done with the causeway 50 years ago. But that system has now established two ecosystems, one on either side that have reached equilibrium and reached a good operating state. To do something that radically impacts either one is going to have lots of unintended consequences.

The people who want bridges and dykes, I really think … they don’t understand what they’re asking for. Because to do a bridge and dykes scenario, the amount of infrastructure that would have to be put in place, including upwards of 30 new aboiteaux on all the small brooks that feed in, which would become the spawning grounds, would become astronomical in terms of cost. And it would also require monitoring. … The majority of people haven’t taken the time to look at all of the facts. It’s a very, very complex issue. And people are trying to simplify it based on emotion rather than on the science.

Fresh water versus fish passage

Darren Porter agrees that this is a very complex issue, one that he says he has been working on for many years. He says he has read thousands of pages of government documents and scientific studies.[3]

In Porter’s view, you can’t have natural fish passage through the tidal dam and still have a freshwater lake. He tells the Examiner that Martock could dig a pond to hold water above the ski hill, which it could use for snowmaking, or lay pipes from upstream in the river and pump fresh water to the hill, where it could be used without harming the equipment, which salt water would.

“As for the canoe club,” Porter says, “in other years when the river was run naturally in 2017 and 2018, they used a lake in Falmouth.”

“And for the farmers upstream who like using the freshwater reservoir, the lake, as a water source for their cattle,” Porter says that is “questionable as it violates both the Fisheries Act and the Nova Scotia Environment Act.” He alleges that 50 years ago when the causeway went in, farmers “scooped up” land where the dykes were:

… and they don’t want to give up anything, no one does. So all the effects of the blocked passage fall on the fishermen, the Mi’kmaq, the fish, the birds, the animals, and we have to give up almost everything. There is no compromise from those on the lake side of the aboiteau. Not one inch.

“I have witnessed more fish kills outside the gates in Windsor than I can remember, and I’ve been reporting on them for years,” Porter tells the Examiner. He says the only reason the fish kills go unnoticed is they happen outside the gates, where they are not visible to the public.

In the spring of 2020, a first ministerial order developed by DFO to increase fish passage was enforced, but not for very long.

The fish kill that killed a ministerial order?

What happened with that ministerial order is more than a little complicated.

According to Porter:

… after DFO put the first ministerial order in for the province to pass fish under the legislation after years of non-compliance [with the Fisheries Act that requires free passage of fish], we had a kill inside on the “fresh water side” of the gates. And the public saw it so it became real! No longer just a fisherman telling them.

Porter explains that because the ministerial order instructed the province to allow Lake Pisiquid to drain, the water upstream from the aboiteau was shallow and pools of warm water formed that killed the fish. To stop this from happening again, he says, DFO then allowed the province to make “a mickey-mouse amendment” to the ministerial order and raise the lake level a few feet.

“This stopped the visible kill inside the gate where the public could see it,” Porter says, “and transferred the killing to the outside, impeding fish passage for the rest of the fish trying to move upriver to fulfill their life cycle.”

Dead gaspereaux outside Windsor aboiteau (Contributed)

The Examiner asked DFO about the fish kills, and received this reply:

On May 28, 2020, the Nova Scotia Department of Agriculture contacted DFO about an incident of fish mortality above the Highway 1 Avon River Bridge. Fish appeared to have become trapped in channels of the river due to low water conditions and likely died as a result of warm temperatures and low oxygen. There was another report of dead fish outside the tidal gates in June of 2014; however, no fish were available for investigation at the time of the report as the tide had removed any evidence.

NSDA spokesperson Dan Davis tells the Examiner that, “on July 30, 2020, NSDA received a formal written warning from DFO due to the failure of the Avon River Aboiteau gates during a falling tide on both June 13 and June 14, 2020.”

Porter alleges that after the fish kill inside the aboiteau, the province went “rogue,” and two weeks later, “DFO allowed the province to raise the lake to full capacity, which blocked all fish passage, but with a twist, as the province said they would implement what they called ‘advanced fish passage measures’ and let only about 10 minutes of salt water in twice a day because they wanted their visible lake.”

After that, Porter says, DFO scientists drafted a new ministerial order which everyone — including the Assembly of Nova Scotia Mi’kmaw Chiefs — expected would be implemented to finally ensure fish passage.

But, says Porter, DFO Minister Bernadette Jordan used “ministerial discretion” to block the order, something he believes was done for purely political reasons to appease what he calls the “old white boys’ club.” In his view, the aboiteau is operating outside of the law that should be governing it, the Fisheries Act, making it “illegal.”

Porter contends that Jordan’s refusal to enforce the ministerial order is evidence that her decision-making is based on politics and not science.

Porter is certainly not alone in his consternation about the minister’s failure to implement the new ministerial order developed by the scientists in her own department.

A Ministerial Order that the minister refused?

The Assembly of Nova Scotia Mi’kmaw Chiefs share Porter’s frustration with Bernadette Jordan’s failure to enforce the new ministerial order. In November, the Assembly issued two strongly worded press releases.

The first, on November 18, stated:

While discussions on the Avon River were making positive strides at the Mi’kmaq-Nova Scotia Canada Consultation table, this week the Consultation Department at the Kwilmu’kw Maw-klusuaqn Negotiation Office (KMKNO), received notice – without explanation – from the Department of Fisheries and Oceans Canada (DFO) that a Ministerial Order (MO) that DFO developed to address concerns with the Avon River was no longer being issued. This MO was to be implemented weeks ago and instead is now being considered – not guaranteed – for next Spring. Despite multiple requests for additional information and the opportunity to discuss this decision further, requests to DFO are largely being ignored.

The draft MO directly spoke to the concerns on the protection of fish and the improvements necessary to fish passage for the critically endangered Inner Bay of Fundy Salmon. “Our primary concern has always been that the current operations of the existing gated structure are impeding fish passage,” said Chief Gerald Toney, Fisheries Lead for the Assembly of Nova Scotia Mi’kmaw Chiefs. “We need these concerns to be rectified immediately and we were hopeful that would be a result of the Ministerial Order.”

“While the MO was a short-term solution, it was a step in the right direction,” continued Chief Toney. “We are now moving out of the Atlantic Salmon migration season, and by having not implemented the objectives outlined in the MO we are concerned that this has only caused more damage and set things back even further.”

Bernadette Jordan
Bernadette Jordan

The Assembly called on “Minister Jordan and DFO to come to the table with answers as it is imperative to yielding healthy results to fish passage in the Avon River.”

Two days later, the Assembly issued a second press release, “Canada not acting in good faith on Avon River.” This time, the Chiefs said that DFO Minister Jordan had agreed to meet with them that day, and then cancelled “at the very last minute.”

The Examiner contacted the Assembly for an update, but has not received a reply.

In addition to the press releases from the Assembly of Nova Scotia Mi’kmaw Chiefs, several environmental groups have backed the call for change in the Avon.

In June, 2020, a letter from seven environmental NGOs urged Minister Jordan to restore fish passage to the Avon River.[4] The letter reminds Jordan that there are:

… excellent and inspiring examples in the Petitcodiac River in New Brunswick as well as the St. Croix River between Canada and the United States that demonstrate fisheries recovery following the removal of tidal and fish passage barriers.

On November 17, to draw more public attention to the issue, water keepers who have been protesting near the aboiteau joined with members of several Mi’kmaw communities and supporters of the Extinction Rebellion to slow traffic on Highway 101.

On November 25, the Ecology Action Centre wrote a letter to Minister Jordan calling for urgent action to ensure fish passage on the Avon, and expressing concern that the progress made on the ministerial order had been “abruptly interrupted.”

Who decides when to open the dam?

Not much is clear about what happened to the ministerial order, and Bernadette Jordan’s department is not being particularly helpful in clarifying it.

The Examiner sent specific questions to DFO about the current aboiteau — why it is not being operated in a way that permits free fish passage, who is responsible for those operations, and why the ministerial order has not been issued and is only “being considered.” None were answered directly. Most answers received were to questions that were not asked about the proposed replacement structure.

These are the only relevant parts of the replies DFO did send about the existing aboiteau:

The Department has been and remains involved in efforts to improve fish passage at the existing causeway …

DFO will continue to review the operation of the aboiteau in collaboration with the Nova Scotia Department of Agriculture and in consultation with the Mi’kmaq of Nova Scotia to ensure that fish passage is being provided to the extent possible, within the limitations of the existing structure.

The Department is considering required measures to ensure fish passage for this coming spring. The Nova Scotia Department of Agriculture currently operates tidal gates at the mouth of the Avon River, and inquiries on its operations should be directed to the province.

Dan Davis, a spokesperson for the Nova Scotia Department of Agriculture tells the Examiner that the NSDA has authority under the Agricultural Marshland Conservation Act for the provincial dykeland system that lies upstream from the aboiteau.

Asked whether NSDA also has decision-making responsibility — either on its own or with other government bodies — for when (how often and how long) the structure is opened and closed for fish passage, Davis replied, obliquely, that NSDA does not have “authority under fish passage, this is regulated by DFO.”

And, he says — again obliquely — that, “NSDA provides subject matter expertise related to the operations of the structure.”

It appears, however, that the NSDA priorities are upstream from the aboiteau, rather than free tidal flow for improved fish passage. According to Davis:

NSDA manages the Avon River Aboiteau to provide flood protection and targets seasonal lake levels established by the Pisiquid Lake Committee. Impacts to stakeholders and right holders require transparency and notification. NSDA has worked closely with DFO over the years to improve conditions for fish passage recognizing the limitations of the structure. NSDA has advised a cautious approach to operational changes to allow for a better understanding of the impacts of these changes to an aging structure.  The structure has been operated for flood control for 50 years. Operational planning to a critical flood control structure requires engineering assessment, understanding, and mitigation of risk.

A much bigger conversation is needed

Susanna Fuller is vice-president, operations and projects for Oceans North. In her view, there are solutions to the dilemma of whether to provide free tidal flow or not, but they will require compromise and changes.

She tells the Examiner that a bridge — as some have requested — would not work, because the whole town of Windsor would have to move.

However, Fuller says there is a happy medium that would allow for more fish passage and tidal flow, and also allow the reservoir to remain, albeit as salt water. The lake, she says, is a good buffer from sea level rise, but it doesn’t need to stay as fresh water:

It would mean a change. It would mean major water users would have to find a different water source. That won’t happen overnight. But personally, I think that is the right thing to do from a biology point of view and restoring fish perspective. That doesn’t mean it’s an easy thing to do.

“It’s complicated,” Fuller says. “But, full stop, we really need to start looking at restoring fish and fish passage more broadly.”

Fuller says she takes a “thousand-foot-view” of the Avon River issue, which she sees as part of a much bigger one that extends across the country and needs to be dealt with.

She says that while Canada has about 15,000 dams, it doesn’t have a way of doing dam removal or a habit of taking them down to restore fish passage and water flow. According to Fuller:

If you look in the U.S., even in the state of Maine, they have been removing dams. As the dams reach the age where they would need to be replaced, they’re actually taking them offline.

Fuller notes that in the two places where dams and causeways have been removed on rivers that flow into the Bay of Fundy — the Petitcodiac and the St. Croix — the rivers are coming back, their ecosystems are recovering. But, she adds:

We don’t do this as a matter of practice in Canada, though, and we need to look at that in a much bigger way. And in particular … when it comes to public infrastructure like the Windsor Causeway, where we have federal money being invested in the highway, we need to make sure that we are not undermining our other Acts, like the Species at Risk Act and the Fisheries Act. How is public money going to further the implementation of those Acts as opposed to continue to exert [negative] environmental impacts?

“We as a society need to decide that we’re okay with rolling back some of the destruction we have wrought,” says Fuller. “And in the Bay of Fundy that has gone on for 300 years. And it’s really a values decision that we need to make as the public.” Climate change makes it all the more urgent:

These issues across the Bay of Fundy are pretty interesting because as sea level rises, we’re one major storm away from destroying about 70% of the dykes in the inner Bay of Fundy … How are we thinking about the Minas Basin, and climate change, and resilience, and natural solutions, and restoring more saltmarsh habitat, and allowing fish passage? Because the fish that come up those rivers are all small pelagics [fish that inhabit the water column not near the bottom or the shore] for the most part; they’re eels and alewives [herring] and gaspereaux and things that recover when you allow them to.

Fuller would like to see a “national perspective and policy” on what we do with dams in Canada. She thinks that that the controversy over the aboiteau and the importance of fish passage on the Avon River will “generate a larger conversation.”

Fuller pauses, and then adds, “I hope.”

[1] Windsor Causeway Survey Report. Oracle Poll, September 2020

[2] The 1965 “Preliminary Study: Avon River Causeway,” prepared by the Maritime Marshland Rehabilitation Administration, Nova Scotia Department of Forestry, states that the Avon River watershed covers nearly 460 square kilometres, the majority of which is in Hants County, but extending also into Lunenburg, Kings and Halifax Counties. Nova Scotia Power had two hydro-power stations upriver on the Avon, one built in 1929 and one in 1958. According to a 2018 Nova Scotia Power report on its hydro assets, the company’s Avon Hydro system outside of Martock, Nov Scotia, involves five reservoirs, five dams and associated spillways, and two canals.

[3] Porter provided many of these studies to the Examiner, as well as this 2005 Masters thesis by Lisa Isaacman on fish populations and anthropogenic stressors in the Avon River, which shows that in addition to the causeway and aboiteau, the stressors include the Nova Scotia Power hydro dam system and pollution.

[4] The June 9, 2020 letter from seven ENGOs to DFO Minister Bernadette Jordan is signed by: Nicolas Lapointe, Senior Conservation Biologist – Freshwater Ecoloy, of the Canadian Wildlife Federation; Matt Abbott, Fundy Baykeeper, Conservation Council of New Brunswick; Mike Crosby, President, Nova Scotia Salmon Association; Susanna Fuller, VP Operations and Projects, Oceans North; Ronald Babin, President, Sentinelles Peticodiac Riverkeeper, and: Elizabeth Hendrisks, Freshwater Program Lead, World Wildife Fund

Joan Baxter is an award-winning Nova Scotian journalist and author of seven books, including "The Mill: Fifty Years of Pulp and Protest." Website:; Twitter @joan_baxter

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  1. I was glad to see a story on the Avon River aboiteau, the twinning of the 101 at Windsor and the efforts of various groups to advocate for their own interests or the interest of migratory fish.

    Whereas Minas Basin experiences the highest tides in the world, it’s not the only hypertidal area in the world that’s also extensively changed by human intervention.

    Three years ago the Halfway River aboiteau failed and for two years that small watershed experienced a return to its glory days as a tidal river. But the citizens didn’t see it that way and wanted the aboiteau fixed and got their way. The Halifax Examiner reported on the situation in August 2019 ( and the article linked to a report by recognized experts CB Wetlands and Environment Specialists ( which was commissioned by NSDA ( that documented how fast and perfectly the Halfway River re-established its natural dynamic.

    We are in a climate crisis and global sea levels are rising as a result. Different countries have developed different mitigation strategies to face this uncertain future: from increasing hard coastal protection structures (‘working against nature’, i.e. hard mitigation) to enabling softer coastlines to develop as a buffer against rising seas and increasing storms (‘working with nature’, i.e. soft mitigation). One of the soft mitigation measures is what’s called ‘managed retreat’: you take out the hard infrastructure and allow nature to regenerate its own resilient environment. An excellent example of soft mitigation is at Cheverie, where the weir was replaced by an open culvert in 2005 (CB Wetlands was involved in the design and monitoring). As a result, a salt water marsh has replaced the fresh water vegetation and the elevation of the marsh has increased. Because every flood tide now brings sediment-laden waters, and – as the current velocity drops close to high tide – these waters drop their sediment on the marsh. And in this manner salt water marshes stabilize at a mean high tide elevation. This is especially true if tidal currents carry a lot of sediment, and the waters of Minas Basin are world famous for having extremely high suspended sediment loads. One of the best places to witness this dynamic is on the Wolfville dyke: the surface of the farmed dykeland on the landward side of the dyke is at least 2m lower than the surface of the salt marsh on the bayward side of the dyke.

    Anyone who is involved in the contentious issue of the Avon River Causeway should at least know about Cheverie Creek and the Halfway River and maybe about similar initiatives near Onslow and the upper Cornwallis River between Port Williams and Kentville. But this appears not to be the case, sadly. The article quotes mr Oulton, who has a farm in the Avon River valley, as saying that ‘saltwater channels are unstable because the tide leads to erosion’. This statement is not supported by evidence. In contrast to river channels, meandering tidal channels, once established, are extremely stable because the bidirectional flow fixes them in their position. Mr. Oulton could have known that if he had bothered to look at the literature about Cheverie creek and the Halfway River or even a little further away.

    I also object to the comments by Sheldon Hope of the Pisiquid canoe club who bluntly states that the marsh in front of the Avon Causeway “has been created by erosion downstream”. This statement is not based in evidence either. The marsh, over which the twinned highway is now being constructed, was deposited there in a short period of time after the closure of the causeway because the tidal currents met a solid barrier and dropped their sediment. Deposition is the opposite of erosion, by the way. The same thing happened at Moncton, when the city built a dam across the Petitcodiac river in 1968. An extensive marsh accumulated as the rip rap for the dam was dumped. In 2010, after decades of activism by the Petitcodiac Riverkeepers, the dam was taken out and the fish returned (as well as surfers on the tidal bore!).

    Building the Avon causeway was a cheap option, a typical solution from the heydays of ‘engineering will fix everything’. Experience everywhere else in the world has shown that most of these hard mitigation structures are environmental failures that cannot withstand the test of time and that are incompatible with our other major challenge climate change. Hence the rise of ‘working with nature’.

    I do not want to suggest that the Avon River issue is a simple one. People in Windsor have come to enjoy a year-round lake. Farmers in the Avon River Valley do not have to maintain their own aboiteaus and dykes, it all happens at the causeway. But this is not a “good equilibrium” as mr Hope suggests. This is, at best, a false equilibrium. I do wish that we don’t choose for another cheap option, but the way the road building progresses across the marsh makes me fear the worst. Why not consider a mixed option? Thirty four years ago, the Dutch – who also know something about tides and sea level and keeping people dry – opted not for a solid dam to protect the people around the Oosterschelde estuary, but for a half open barrier. The reason was that the solid dams they had constructed earlier along other estuaries proved to be failures: the resulting freshwater lakes quickly suffered from anoxia. The Oosterschelde storm surge barrier reduces the tide range in the estuary by about 20%, which enabled the continuation of oyster farms and it can close completely during a storm, thus protecting the communities around the estuary. Yes, it was expensive, but it protected both fish and people. Lake Pisiquid has to be drained every so often because it too becomes anoxic. Yes, we do need a national conversation about these issues, can we just begin by having one with all stakeholders from Nova Scotia and New Brunswick?

    Marshes are important for providing primary nutrients (carbon) to the bottom of the food chain. We have locked 85% of our Fundy marshlands behind dykes. We wonder why we have issues with fish stock. We also know we must sequester Carbon to combat climate change. Marshes are a huge carbon sink, if we manage them well. See this story I wish someone would have the guts to take a bold step and design a sustainable solution instead of maintaining the status quo.

  2. This is hogwash about inundating land. The farmers and the town have removed many of the protective dykes. The tide used to come in as far as the mill section up the Chester road. In my mother’s lifetime there was free flow of the river. There are two separate river systems that combine into the Avon and they are damaged by not having the ocean scour. I grew up on those banks and I can tell you too much development was okayed in what are flood plains. If you go up the mines road you can see the old dykes. A million board feet of lumber was floated or barged down the river as well (a harmful process). If ships used to tie up in windsor and barges could go up the river, I’d say the river is heavily laden with silt as it is very shallow in many places now with no high tide to move things regularly. We often have terrible ice jams at the headwaters.

  3. Let us implement the Happy Medium Susannah fuller describes: However, Fuller says there is a happy medium that would allow for more fish passage and tidal flow, and also allow the reservoir to remain, albeit as salt water. The lake, she says, is a good buffer from sea level rise, but it doesn’t need to stay as fresh water:

    It would mean a change. It would mean major water users would have to find a different water source. That won’t happen overnight. But personally, I think that is the right thing to do from a biology point of view and restoring fish perspective. That doesn’t mean it’s an easy thing to do.

    “It’s complicated,” Fuller says. “But, full stop, we really need to start looking at restoring fish and fish passage more broadly.”

  4. Thankyou for dissecting this crazy-complex issue! As a concerned-supporter-of-safe-fish-passage, but one who lives on the other side of the province, I greatly appreciate knowing much more of the full-picture.

    “We as a society need to decide that we’re okay with rolling back some of the destruction we have wrought,” says Fuller. “And in the Bay of Fundy that has gone on for 300 years. And it’s really a values decision that we need to make as the public.”

    Surely to goodness, this so-called enlightened / informed society can make this happen, despite the very significant, ongoing stonewalling of Bernadette Jordan, minister of fisheries oceans and coast guard. She who single-handedly is blocking the efforts / conclusions of her own department; who is
    dis-respecting the Mi’kmaq; and ignoring the survey of local residents; NGOs; various studies and commercial and recreational fishers.

    Why is she stalling until Spring 2021? Perhaps she expects to have been shuffled out of the department by then? That would be appropriate.

    Her actions on several key issues demonstrate that, despite being from Nova Scotia, she has no love for the ocean habitat or its dwellers . . . Unless they’re in or on “her” LaHave River.

  5. Great article, thanks for the detail. It’s not just behind the causeway where natural processes have been impacted. I remember circa 1976 crossing the causeway in a car with some oceanographers going to a meeting at Acadia where they would discuss another causeway – the Annapolis causeway/Tidal Power scheme- that proved subsequently to be highly flawed, like the Windsor Causeway. As we viewed the growing mudflats outside of the causeway , they said this was not predicted by the best tidal experts, it had been expected that the area would be maintained as a harbour. I watched over the next 10 years as cord grass came and went and then finally got firmly established and spread and stabilized and expanded the elevated mud flats. At the same time there was tremendous erosion in the area of Evangeline Beach, undoubtedly related to the causeway, the silts that would rush back and forth with the tides and maintain the beach were now being trapped upstream. Anyway, I’m with Darren Porter’s perspectives on this one. We have to figure out ways to re-establish the natural flows and protect as nec. the town and agricultural fields, at least those still in use.

  6. Susanna Fuller speaking reasonable (again). Drive down the main drag in Windsor. Now imagine it during a high storm tide. I am told by those who know, that there would be up to three feet of water to drive through. All the businesses along there would be underwater inside (except maybe Schoolhouse Brewing which is elevated above the parking lot). A golf course can deal with intermittent flooding, even if it is salt water. But a business or a home cannot.

    It is totally possible to do what she says – to create a fish passage that is operational when fish need it to be that limits how much damage a high tide can do. The fish do not need an opening big enough for a boat. They need one big enough for a fish. The amount of water flowing through a pipe has limits, and in a tidal regime, the flow in one direction only lasts for 6 hours before it goes the other way.

    I actually believe that it might be possible to create a second restriction under the newer Falmouth bridge, and then a salty “forebay pond” would exist that would buffer both salinity and elevation, and greatly reduce impacts on the freshwater users upstream. But they didn’t ask me for my advice. 😉

    I did, however, calculate how much water would flow between the two sides with a pipe diameter large enough to pass the fish whenever they felt like it. The volume of salt water flowing upstream is minimal compared to the volume of the lake that is there now. And not enough to raise the lake elevation to flood downtown Windsor, and compromise the farmland around the lake. And then, when the tide reverses, the water flows out. At the same low rate.

    This may not work exactly as I have simplistically described, but I cannot believe that there is not a solution that improves and even restores fish passage while managing the lake level.