City employees inadvertently drain Bromont marsh
Several acres of marshland in the Parc scientifique de Bromont nature reserve have been inadvertently drained as a result of city employees carrying out unauthorized work to dismantle a beaver dam, city officials and conservation groups have said.
“The water was overflowing onto industrial land outside the conservation area. So [the employees] created a breach. But unfortunately, this is not the intervention they should have made, and no one within the general management and the city council was aware of this,” Bromont director general Francis Dorion, who was not available to speak to the BCN before the Easter holiday, told Radiocanada. Local birdwatchers brought the damage to the attention of city officials early last week.
“No one at the city is happy about this,” said Dorion, adding that the city “will do everything possible” to repair the damage.
He said the municipality had the legal right to dismantle beaver dams that threaten human safety or property, but “additional analysis” should have been done before the decision to dismantle the dam was made.
“It’s a deplorable situation, but we don’t want to cast blame,” said Mélanie Lelièvre, president of the local conservation nonprofit Appalachian Corridor, who learned about the damage to the marsh from media reports. “We know the city is on the case – it’s human error and we know they’re looking into it.”
Lelièvre explained that the marsh, which covers about three acres of the 200-hectare park, represents a small but ecologically important part of the reserve. “It’s a really important natural milieu, where we find a lot of plants and animals. There are tortoises and least bitterns [a wetland bird; a rare, tiny member of the heron family].”
According to Parks Canada, beavers create wetlands by building dams and allowing water to pool in ponds. When water builds up to the point where it threatens human activity, tools such as Morency cubes – metal cages which redirect water flow – can help control water levels while keeping dams largely intact, Lelièvre said. In general, Lelièvre said, wetlands “do us a lot of favours ecologically.” Wetlands filter pollutants, reduce erosion and act as natural sponges, absorbing water in wet weather or high tide and retaining it during drought. In light of climate change, she said they are “more important than ever.”
Lelièvre said water levels in the marsh should return to normal over time if the weather co-operates, but that the medium- and longer-term consequences of the breach, if there are any, would not be known for some time. “If we get normal rain in the next few weeks, the water level should be back to where it was, or close to it, but if there’s no precipitation, that will complicate things. If we get the water level back to normal, there should not be consequences for the area as a whole – we should still have a proper nesting area [for birds]. We don’t know about the impact for the amphibians and reptiles who spend the winter in the surrounding mud – did they have the time to dig deeper or find another place? We don’t have the data yet, so we don’t know.”