When the Town of Niverville realized they had a problem with the ponds in Fifth Avenue Estates, they knew they needed to fix it. The issues are myriad and include shoreline erosion, an abundance of goose fecal matter, and the overgrowth of water plant life such as duckweed. However, the most concerning problem is the growth of blue-green algae, which can be hazardous both to people and small animals.
Since identifying the problem through regular testing, mandated by the province, the town has deliberated on many possible tactics, aiming for a solution that satisfies budgetary needs, environmentalism, and local preference.
In December 2020, the town made the decision to install cattails, a plant species native to Manitoba, along the shoreline to help neutralize blue-green algae.
About this decision, a number of residents are not happy.
Bruce Friesen-Pankratz is a wetland scientist for Native Plant Solutions, an organization affiliated with Ducks Unlimited which designs and installs natural solutions to water quality issues. Notably, they specialize in solutions that don’t require the use of chemicals. They have produced the naturalized stormwater pond designs adopted by cities such as Winnipeg and Brandon, as well as other communities across Canada.
In 2020, the not-for-profit worked with the town to provide a study on the health of three ponds within Fifth Avenue Estates and found levels of 234,000, 306,000, and 541,000 blue algal cells/millilitre respectively. The federal guideline is 100,000, meaning that the ponds in Niverville have up to five times the recommended safe amount of blue-green algae.
“In our experience the most economical and environmentally friendly way to address blue-green algal issues is to use natural approaches to reduce the available nutrients, typically phosphorus, that are causing excessive algal growth,” says Friesen-Pankratz. “The scientifically proven natural approach involves the use of native cattail to remove nutrients from the water column, storing the excess phosphorous both within the plant and in the pond sediment.”
The cattail approach has already been used in Niverville to decontaminate the southern portion of the old sewage lagoon. That project has resulted in a safe wetland environment.
Aside from planting cattails, the town has also discussed the option of placing tarp and river rock along the shore to address soil erosion, dumping gravel and rocks on the bottom of the pond bed to prevent growth of unwanted vegetation, an increased use of aeration machines and fountains to disturb duckweed growth on the surface of the water, and chemical additives that counteract the algae.
All of these options come with certain price tags and environmental ramifications.
Mayor Myron Dyck says council has come back to this discussion many times and relies on research and input from experts to help aid them in their decision-making, especially in areas that go beyond the councillors’ firsthand expertise.
Solution #1: Chemicals
One thing council learned early on is that the ponds were never designed to be lakes, with all the recreation connotations that go along with that term. Mayor Dyck says that retention ponds have become a near requirement from the province when it comes to new developments, designed to manage excess runoff.
“They subvert and hold water from our spring melt and our occasional seven-inch rainfalls,” says Mayor Dyck. “Before Fifth Avenue [Estates] was built, water would come from Hanover through Niverville on its way to the Red River. That’s how the topography of the land flows… and we would have water from springtime and high-water events coming through places like Edelweiss Crescent where water would come up to people’s properties and come in window wells even. Even if we would put in an ecologically responsible chemical solution, the water would move on and need to be treated repeatedly.”
He says that the town ran some rough numbers, and their final decision came down to the sheer cost of this option.
Friesen-Pankratz also has concerns about going the route of a chemical solution.
“We wouldn’t recommend chemical treatments,” says Friesen-Pankratz. “There is one solution that is sometimes used, but it results in a sort of sludge at the bottom of the lake, which isn’t healthy. The Town of Niverville is within the Lake Winnipeg watershed. Chemicals added to stormwater systems within the Lake Winnipeg watershed can flow downstream, causing ecological impacts along the way and could eventually end up in Lake Winnipeg.”
Solution #2: Gravel
Another idea discussed by the town was to install stone along the bottom of the pond to encourage filtration and reduce vegetation, and place tarps and gravel by the shoreline to reduce erosion.
“But we looked into the cost of stone per tonne, and renting a barge to transport stone to the lake, and we would be looking at a cost point of easily hundreds of thousands of dollars,” says Dyck.
He adds that some communities use a form of tarp fabric to help with shoreline stabilization. This is known as the wrap method.
“I don’t know the science behind cleaning the wraps,” Dyck says. “I understand it’s more of an aesthetic thing, so that doesn’t solve the problem of cleaning the pond of the blue-green algae. And again, there is more upfront and ongoing cost associated with that.”
Solution #3: Aeration and Fountains
The Native Plant Solutions report also covered options like aerators and fountains, which council at one point indicated would have been their preferred approach.
“In some systems I’ve seen, including fountains, they tend to just push the floating duckweed to the edges, which is unsightly to residents,” Friesen-Pankratz said at a council meeting on October 6, 2020. “But it still grows. So you’re mostly moving the decomposing matter, just stirring it up, which stimulates further decomposition. There is more upkeep in the long run to remove the dead matter and you’ll end up with higher levels of algae in your ponds. Algal communities reproduce so quickly. In a natural system, you have many algal communities that can uptake the nutrients at different points in their lifespans and clean water systems more efficiently. Aeration, though, is usually for promoting fish life, so they can have available oxygen. For algal communities, you want to control the phosphorous levels.”
Niverville currently uses some mechanical agitation to increase the flow of water out of the community, but council notes that it has a limited effect on duckweed and almost no effect on blue-green algae.
Solution #4: Cattails
The natural approach to wetland areas is typically the most effective in making a safe environment for kids, pets, and wildlife that will inevitably come in contact with the ponds. The annual influx of geese is the form of wildlife that currently has the most impact on the ponds. These large birds often choose to nest on the shoreline and their fecal matter is rich in phosphorus and nitrogen, contributing to algal blooms.
Friesen-Pankratz says that cattails will help solve this problem since they make the shores much less desirable for geese to nest in.
“The reason you see geese on properties is they prefer grass that is short,” he explains. “By using native grasses, longer grasses, you discourage geese from coming up from the ponds onto people’s properties.”
He says that cattails along the shore will also solve the town’s other concerns. Cattails absorb nitrogen, phosphorus, and other elements, directly mitigating the growth of blue-green algae, and according to Native Plant Solutions they will lend erosion protection, trap sediment and nutrients from surface runoff, regulate the water temperature, and improve water quality for fish as well as downstream lakes and rivers.
At approximately $10,000 per pond, the price point for cattails is also low.
Concerns from Residents
Jacqueline Robert is a Niverville resident whose backyard directly faces one of the ponds in Fifth Avenue Estates. When the option to install cattails first came up more than two years ago, she helped rally residents to speak up against it. More recently, she has helped form a social media committee with approximately 45 members.
She says that she has spoken to property owners in other developments with retention ponds, such as the Sage Creek and Bridgewater neighbourhoods in Winnipeg, who also dislike cattails. According to Robert, complaints about cattails include swampy smells, vole nests, rats, and mosquitoes.
Robert’s main concern is that the cattails would need to be cut regularly to keep their growth from impeding upon activities around the ponds.
“The process of cutting this stuff is not easy, and costly,” says Robert. “Companies would need to be hired to cut this and it’s an ongoing cost.”
In winter, residents have helped clear the ice for activities like skating, and Robert is concerned that, with time, the plants will eventually grow into the middle of the ponds and make these sorts of activities difficult.
“If there’s bulrushes, it disrupts the skating possibilities,” Robert says. “In a couple of years, the bulrushes will take over and we won’t be able to do this anymore. There will just be bulrushes.”
She says that the residents with property around the ponds feel a sense of ownership, and many of them are environmentally conscious and take great pride in maintaining their yards and gardens.
“I’m a gardener,” she says. “I am four years pesticide-free. Because my yard is organic, I have no mosquitoes. I have spiders, dragonflies, and everything that eats them. Everybody here cares about their yards… Had I known that this was going to happen, I would not have put $150,000 into my backyard to have to look at bulrushes.”
Robert says she knows it’s a complex issue and acknowledges the town did a study and wants to be environmentally and budget friendly. But she maintains that the town isn’t doing enough to find a solution other than cattails.
She also claims there is a chemical that will work in the ponds of Fifth Avenue Estates, something called a pond conditioner. She says it’s less expensive while also being good for fish, pet-friendly, kid-friendly, and effective at getting rid of geese.
Robert says that her cousin, Robert Sarrasin, uses a product like this in his pond on the grounds of Waldenway Canine and Kitty Camp near Ste. Anne.
Sarrasin confirmed that he uses a product called Blue Pond, but his pond is what is considered a stagnant pond, meaning it doesn’t drain. In fact, they usually need to add water in the summer during long periods of hot weather.
The ponds in Fifth Avenue Estates are not stagnant and do not fall into the same category.
Reassurances
The Citizen asked Friesen-Pankratz for his professional assessment of the concerns raised by residents such as Robert, and he largely offered reassurances that cattails are the soundest option.
Notably, he says that he has seen the use of these natural systems in other subdivisions and it hasn’t impeded the use of ponds or reduced access to them. He adds that the depth of the ponds in Fifth Avenue Estates will surely prevent cattails from growing out into the middle and prevent winter skating.
“Shallow water zones support the growth of wetland plants. The middle section of the pond is often the deepest area and contains open water only,” Friesen-Pankratz says. “Cattails are limited to the edge of the pond where water depths are shallow. The cattail plants will not ‘take over’ a naturalized stormwater pond if it’s designed correctly, as the depths in the middle of the pond will be too deep for the cattail to grow.”
He also disputes the idea that the cattails will be costly to cut and maintain.
“With the proper stormwater design, wetland plants in these systems will never need to be trimmed or harvested. Nor will they require any additional management by the town, or chemical applications or external products to control blue-green algae in the future.”
Relying on Experts
Mayor Dyck recognizes that the installation of cattails isn’t a popular decision with certain residents and agrees that their concerns need to be heard. He says that he’s aware of their social media group and that he has spoken with Jacqueline Robert.
“There are solutions flying around, which are appreciated. And to residents, we welcome your ideas,” says Dyck. “The truth is, there are some problems we need to fix [on the ponds] and we are trying to do it as economically as possible. We need professionals and engineers to look into this, to look at our water health.”
Dyck has explained that when town council looks at solving a complicated problem like this one, it’s standard operating procedures for council to approach professionals who deal with the issue at hand and learn from their input and expertise. This provides the general population with assurance that council is receiving expert information instead of relying only on firsthand experience and anecdotal evidence.
“Council doesn’t want to run to a professional to conduct a study every time and spend money willy-nilly, so we do strive for a balance there,” says Dyck. “That’s one reason why we hired our own in-house engineer, so we don’t have to run to an external source to do in-house planning anymore. But in matters such as this, dealing with shorelines and the importance of healthy water ecosystems, we knew we needed to reach out to Native Plant Solutions, who are not-for-profit. They conduct their services for free. They weren’t paid.”
Dyck says he has asked the town’s CAO to put some more numbers together on other options for pond solutions.
In the meantime, the cattails will begin to be installed at one of the ponds. That decision was made on December 15 and a notice was delivered to Fifth Avenue Estates residents in the middle of January. Taillieu Construction Ltd. will begin digging trenches in preparation for the planting to begin.
The town also notes that construction crews are aware of the ponds being used for winter recreation activities and skating.
“Yes, we can start work on this in winter,” says Mayor Dyck. “The town is cognizant of the skating rinks, and we’re willing to work on making sure there is still safe access to the skating areas.”
However, Dyck also points out that this is an ongoing discussion.
“We like to hear from residents and we will talk to residents. If there is a cheaper way to do this by a capital and operational standpoint, while also being ecologically sound and aesthetically pleasing, we would look at it. But we are tasked with solving problems. Like any family budget, there’s always way more things that need doing than you have money for… Our town has many priorities and we are just trying to deal with it and get by with something that will work.”