The city wants to dig a million-dollar hole to prevent floods and bring birds back to Heritage Lakes.
Heritage Lakes residents gathered at école La Mission elementary Thursday night for an open house on the Havenwood stormwater pond. The pond is near Heritage Way and Heritage Drive and is meant to resemble a prairie wetland.
And that's the problem, says Todd Wyman, the city's director of engineering. When it was built in 1996, the designers tried to preserve an existing wetland by building a berm with a weir next to it. Water was meant to build up behind the weir, flow under the berm, and create a lake.
"Like any prairie marsh," Wyman says, "it can dry up and have no water inside." On Thursday, for example, the lake was the size of a large puddle. "Unfortunately, we don't like that when we're living beside these things."
Recent droughts have caused the pond to fill with duckweed, dry up and stink, driving away much of its bird life, Wyman says. City staffers have fiddled with the height of the weir to raise water levels, but doing so damages the berm, reduces the pond's stormwater capacity, and takes a lot of labour.
A recent stormwater management review also found that the pond was not big enough to handle a one-in-100-year rain, creating a flood risk in nearby homes. "We decided we needed to do something rather drastic."
Deeper pond
The city wants to deepen the pond by about two meters in the middle so it can hold more water, Wyman says. Lowering the pond should keep more water in it year-round, making it more attractive to birds. Staff would eliminate the berm and weir since they don't work and add another outfall to the pond — it only has one now, and plugs easily.
This would mean removing some of the vegetation and soil around the edge of the pond, says project manager Larry Galye, adding tree stands would be left alone. That soil would be stockpiled and restored after construction, which should preserve most of the region's plants. The city made similar changes to Grandin Pond about a decade ago, he notes.
The project should cost $1 million, Wyman says, and is listed as funded in the city's 10-year utility capital plan. If approved in the 2011 budget, the city would start digging that winter and finish planting by spring. Vegetation should grow back within a year. "By fall, it'll be amazing."
The city would review the environmental impacts of the project before it starts digging, Wyman says. City environmental manager Leah Jackson says any frogs or reptiles displaced by the work would likely come back in a few years.
Locals like it
John and Lucille Piers have lived by the pond for 11 years, and say it's never worked as intended. "The dam has always been too low," John says. "The water flows out and nothing ever comes into the lake."
The result is an ugly pond, says Lucille. "It looks like a dried-up slough," she says. "There's no birdlife or anything on the pond anymore."
Both like the city's solution, but wondered about its cost. "I don't know why they can't just keep the level of the pond up," Lucille says. John wondered if the city could pump water into it as an interim solution.
Residents have complained about this pond for years, says Mayor Nolan Crouse. "People expect [the pond] to be there and it's withering away."
Council would likely approve a fix for the pond this October, Crouse says, which would be paid for through a previously approved 9.5 per cent hike in utility rates. "This is part of our infrastructure that was not done properly in the first place and we're going to fix it."
The project goes before council during budget talks this October. For details, call project manager Sue Howard-Carmichael at 780-459-1654.
