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It’s being referred to as the perfect storm. A few warm nights, a lot of rain and tons of snow in Algonquin Park has turned the spring of 2019 into a major flood event. In this region alone hundreds of property owners have been impacted by flooding, which coincidentally started in the middle of a public holiday.
The Muskoka River watershed, which flows from Algonquin Park to Georgian Bay with many lakes, rivers, wetlands, and communities in-between, contains 42 water control structures, or dams. Eleven of those structures are owned and operated by the hydro generation sector, one is owned and operated by the District of Muskoka, another is privately owned and operated and the remainder 29 dams are owned and operated by the Ministry of Natural Resources and Forestry (MNRF). So if the MNRF owns the majority of the dams, is it able to control flooding in the Muskoka watershed?
Not according to partnership specialist with the Ministry, Mara Kerry. “None of the dams on the watershed are flood control structures. None of them,” she said. “The dams that we have on the watershed were built quite a while ago, some of them a century ago.”
Kerry said that while the dams have been maintained and upgraded since then, they were built “to keep the lakes high during the summer for industry, for timber, and for boat navigation. So we can manage the levels and flows within a certain range, but if you get extreme weather or extreme precipitation, then you know, in order to stop flooding, you need some kind of a reservoir.”
She used the Red River Floodway in Manitoba as an example. “Think of the floodway they have in Winnipeg. It just diverts all the water away and floods out basically in Winnipeg all these farmers’ fields, so that’s the reservoir. So you would need to shift that water off somewhere else and store it in a big basin, and we don’t have that.”
Kerry likened the lakes in the Muskoka watershed to thousands of bathtubs made up of different shapes and depths located in areas from Algonquin Park to Georgian Bay and the dams operated by the MNRF being the drains. Even with the drains wide open, if the water flowing into the bathtubs is flowing in faster than it’s flowing out of the drains, eventually it’s going to overflow onto your bathroom floor, she noted.
“Every year prior to the freshet we lower the lake level because we know every year it’s going to warm up, the snow’s going to melt and it’s going to rain so we draw the lakes down to the low end of the normal operating zone so that we make room to accommodate the spring freshet. That was done,” she said but noted that the water started flowing quickly this spring, it was accompanied by warm temperatures, and there was a lot of snowpack in Algonquin Park.
Asked how the generation of hydro impacts water levels, Kerry said “they don’t have reservoirs either where they hold back water to be able to generate power in times of low flow. It’s basically a turbine that’s in the river and it’s generating energy when the water’s flowing, and if it isn’t flowing they’re not generating very much energy.”
What about drawing a lake even lower than the operating range spelled out in the Muskoka River Water Management Plan (MRWMP), especially if a bad year for flooding is anticipated?
It’s a gamble, said Kerry. “You potentially could, but there are consequences to that. So if you, let’s just say, hypothetical situation, you emptied half the lake and then you don’t get any rain and you have a really low year with snowpack or the snowpack melts gradually, then what do you do in the summer? You’ve got a lake that’s half empty… and then you’ve stranded all the fish that live in the lake, all the trout that spawn in the fall…people’s water lines are out high and dry, there’s a lot of implications.”
She said the role of the MNRF through the water management plan is to balance economic, environmental and social interests in the watershed.
“Each of the lakes where there is a dam has what’s called a normal operating zone where we try to maintain levels within this zone, and it’s only when it gets too low that we run into troubles with rocks and people’s waterlines and so on, or when it gets too high. So within the normal range of variation, the water management plan is very effective,” she said. “But it is a balance. And when you have high water or low water, you have to spread that sort of pain out across the watershed,” she added. “We certainly can’t prevent flooding in extreme conditions, but you can manage it within a range.”
As for Huntsville, in particular, Kerry said there are a number of challenges. “There are buildings built on the floodplain that probably should never have been built there, but also there’s the geography of the area. So you’ve got the natural geography sort of pinching all the water coming out of Fairy Lake and [then]further upstream into the [Vernon] narrows. So it can only flow through there so fast, so it backs up. So it’s kind of a product of its location, unfortunately.”
On Tuesday, April 23, Kerry said that all of the dams in the system were open. “Nobody is holding back any water. Everything is running through the system as fast as it can. So what our crews are doing is making sure that there’s no debris blocking the dams, because when you get flows like this you can get people’s docks or trees or picnic tables… if they get caught up in the dams, they can obstruct the flows. So we’re checking them daily for debris, every single dam in the whole watershed and on the Magnetawan, as well as making sure that they’re structurally in good shape.”
What if all the dams and weirs in the system were removed and we simply stopped controlling water flows?
“That’s an interesting question to ask the public, it certainly has implications. What you will get then is a more natural watershed for sure, which has some advantages, but you’ll be prone to extremes—really high water and then really, really low water, and everything in-between.”
Muskoka Lakes Mayor Phil Harding has been particularly critical of the MNRF on social media. He accused the Ministry of not drawing down the system enough, given the amount of snow accumulation in the region.
“Back in March the MNRF admitted they have higher than average snowpack with water content at 171mm. And yet they left Lake Muskoka water levels higher then they did in 2018 (with lower snowpack). Were they anticipating blow (sic) average temperatures and no rain whatsoever from April – July this year? If they anticipated “average” temps – Lake Muskoka should have been drawn down lower than last year,” he posted on his Facebook page on Thursday, April 25.
Harding also questioned why the MRWMP has not been updated since 2006, and taken climate change into account.
John Yakabuski, Minister of Natural Resources and Forestry, in a statement issued on Sunday, April 28, 2019, said that his Ministry has been monitoring the snowpack in Muskoka since last December.
“By February, the Ministry had removed all logs in the south dam to allow maximum flow through the system. In fact, Lake Muskoka was drawn down to one of the lowest levels in recent years to account for the rain and warm weather expected through April,” he noted in the release. “Our government understands the environmental changes facing Muskoka, including increased developmental pressures, severe flooding and weather events. That’s why in August of 2018 we provided $5 million to support the Muskoka Watershed Conservation and Management Initiative, led by the Ministry of Environment, Conservation and Parks, to help us develop a more comprehensive approach to watershed management in Muskoka. We are committed to working with the local community to protect this vital area.”
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