WATER LEVELS – ONE YEAR LATER
The interplay between humans and the natural world is complex – the subtle (and not-so-subtle) actions of one can have far-reaching implications for the other in ways sometimes unanticipated.
One need look no further than the flooding events of recent years in Muskoka – floods of the century in both 2013 and 2019 – to see just how complex that dynamic can be.
On the surface, it appears simple: water levels rise in the spring as snow melts and rain falls, flooding sometimes occurs due to that excess flow, and then the water recedes once again until the next year, save for weather anomalies like a heavy deluge in a summer storm.
But start to dig into the cause of the flooding, and you very quickly find the answer isn’t a simple one.
There’s the complexity of the Muskoka watershed for starters: its drainage basin comprises about 5,100 square kilometres, several hundred lakes and tributaries, and contains constriction points – both natural and manmade – that restrict the volume of water that can pass through those areas.
Add in human developments built over the years – parking lots and roads, subdivisions and commercial areas – that reduce the available ground surface for absorbing meltwater and rainwater. Often wetlands, which are known for their capacity to retain water, are being lost to the desire for buildable land. And then there’s the effect of climate change, which can cause greater precipitation and a faster melt during the spring freshet, as well as increasingly extreme weather events.
Governments at all levels have taken notice.
There have been funding announcements: in August 2018, the province committed to a $5 million Muskoka Watershed Conservation and Management Initiative to look at risks to the watershed, flooding among them. A $1 million pilot project announced in 2019 will provide municipalities that qualify for Municipal Disaster Recovery Assistance (MDRA) funding with up to an additional 15 per cent beyond the estimated cost of rebuilding damaged public infrastructure in an effort to make it more resilient in extreme weather events. One example is raising roads to improve overland flow of water, as might have helped Beaumont Drive in Bracebridge which had to be built up, in the middle of the 2019 flood, to allow stranded residents to pass.
Reviews have been initiated: following the most recent round of severe flooding across the province in 2019, Ontario’s Minister of Natural Resources and Forestry, John Yakabuski, named Doug McNeil as special advisor on flooding, with the task of conducting an independent review of the flood events and flood management in the province. And less than a month later, the Muskoka Watershed Advisory Group was appointed – its members will provide advice and recommendations to help protect and conserve the Muskoka Watershed and support economic growth in the region. This advisory group will deliver its report this year.
McNeil’s report was released in October 2019. In his review, he noted weather played a significant part in the flooding: colder-than-average temperatures throughout the preceding winter and early spring, limited winter thaw, a deeper-than-average snowpack, and both rapid snow melt and significant rain in the spring.
He also determined that “nothing points to human error or the negligent operation of water control structures as the cause of the flooding… Measures taken by water managers everywhere were effective in reducing the magnitude of flooding and associated damages throughout the drainage basins.”
McNeil reiterated what may have come as a surprise to some residents: that dams operated both by the Ministry of Natural Resources and Forestry (MNRF) and private operators throughout the system do not help to prevent flooding. “...(D)ams are not flood control structures and have very limited capacity to store or hold back flood waters, as they have little to no lake or reservoir capacity,” he wrote. “As a result, in a large volume, rapid runoff flood, the dams have limited capacity to reduce peak water levels. The greater the flood event, the less ability the MNRF/dam operators have to mitigate the impacts.”
His recommendations for the Muskoka region included a call for the Ministry of Environment, Conservation and Parks (MECP) to “consider whether to encourage the municipalities to establish a conservation authority or request the Ministry of Municipal Affairs and Housing to restrict development in the floodplains,” as well as “use the results of the Muskoka Watershed Conservation and Management Initiative to inform any potential future amendments to the Muskoka River Water Management Plan.”
MPP for Parry Sound-Muskoka, Norm Miller, said that given the circumstances in 2019, “I’m not sure that anything last year would have made a difference.” He says he has heard from the Township of Muskoka Lakes, in particular, about the need for changes to the Muskoka River Water Management Plan (MRWMP). On behalf of the Township, Miller had requested a meeting with the ministers of both the MNRF and the MECP about their concerns, a meeting that had not yet taken place at time of publication.
On the subject of climate change, Kevin Boyle, climate change co-ordinator, District of Muskoka, says, “if you look at the Muskoka Watershed Council’s 2016 Planning for Climate Change Report, the indications are that basically it follows similar patterns to most of Ontario which is warmer, wetter, wilder.
“(By 2050) we will have about 10 per cent more precipitation on average, but that precipitation won’t fall evenly so it’ll probably be an increase of 17 per cent more precipitation in the months between November and April, when we already have challenges managing water, of course, and then we’ll have a bit of a drier sort of July/August period,” says Boyle.
“An analysis would indicate that we’re likely to slowly have more and more challenges dealing with precipitation in the freshet,” he continues. “We could potentially see an increase in flooding moving forward, but of course it’s extremely hard to predict flooding on a year-to-year basis. Basically it’s controlled by three factors: amount of precipitation, water equivalent in snow pack, and temperature. We can measure water equivalent in snow pack; the other two are sort of wild cards just because we’re really not great at predicting weather.”
From a standpoint of mitigation, one of the most important things to do is to not build in a flood plain in the first place, observes Boyle, who points to the recent flood plain mapping as an important tool in identifying areas that are vulnerable to flooding.
He also encourages property owners to clean up their property in the fall and remove things like chairs or paddleboards, especially on a river that would have current that could carry it away.
“Whenever we do have a flood event, there’s all sorts of stuff that ends up in the river that can lead to jams at the dams, in addition to losing your material,” Boyle says.
“If you think that your house or your cottage might flood, remove valuables from your basement or your main floor, or at least stack them up. Look at turning off your power before the freshet. And consider not leaving your boat in your boathouse over the winter.”
Individual property owners can take actions that will help the big picture.
“On a larger scale,” says Boyle, “protecting our wetlands, naturalizing your shorelines to increase the lag time for runoff to try to sequester as much water as possible, and planting trees, those are things that are long-term but easier things that we can do to slow or control some of the flooding. But we’re not at the point now where we have one project we can do that would prevent flooding in Muskoka.”
The Muskoka Watershed Council (MWC) also believes that changes need to be made to the way the watershed is managed but that the MRWMP isn’t enough.
In a Feb. 18, 2020 letter to the Muskoka Watershed Advisory Group, MWC chair Geoff Ross wrote that “revising the Province’s Muskoka River Water Management Plan alone will not assist in mitigating the causes of flooding and identifying innovative, comprehensive watershed management options. More specifically, a watershed hydrology initiative, in the context of a comprehensive watershed strategy, will provide broad insight and potential solutions for greater flood resiliency.”
The organization prepared a white paper, “The Case for Integrated Watershed Management in Muskoka” – authored by Peter Sale, Kevin Trimble, Richard Lammers, Christy Doyle, Geoff Ross, Norman Yan and Patricia Arney – that outlines how such a strategy could be implemented.
“The Muskoka River Water Management Plan is restricted in scope and responds primarily to river flows, snow pack and lake levels,” Ross wrote in his letter, “while a broader watershed strategy should include assessing our built and natural infrastructure (including but not limited to wetlands, headwater tributaries, and forest resources) to fully understand and, in turn, to effectively manage the impacts of flooding and to identify necessary actions to ensure the ecological and economic health of Muskoka, and beyond, for years to come.”
An integrated management program would be built on the most current watershed data available, including the flood plain mapping recently completed by the District of Muskoka and consultants from Hatch Ltd. and funded, in part, through the National Disaster Mitigation Program (NDMP).
The flood plain mapping project aimed to identify areas across Muskoka that are at risk of seasonal flooding. According to the District of Muskoka website, “the goal is to have more information to assist with emergency management plans and help inform planning policies… Flood plain mapping is also critical to support informed decisions and investments to reduce the impacts of flooding in our communities. Development in these areas can result in damage to properties if flooding or erosion occurs, and in extreme cases could result in loss of life.”
Integrated watershed management would also consider the impact of climate change, the extent of which is a somewhat unknown variable.
“One consequence is that over future decades, climate change will exacerbate the seasonality and extent of water flow by directly altering patterns of precipitation, evaporation and transpiration, as well as by radically altering soil moisture, and water-holding capacity of wetlands,” note the MWC whitepaper’s authors. “We should seek ways to maximize our use of available natural capital in managing the flow of water through the watershed. These issues reveal an immediate problem. We lack a sufficiently detailed understanding of how natural capital affects flow from place to place across this watershed, and how climate change may modify these regulating processes.”
Which makes measures to address climate change all the more important. MPP Miller says his government is working on it.
“The government has started the first-ever province-wide evaluation of preparedness for climate change,” he said. “And, of course, we do have a made-in-Ontario environment plan, which has a number of different actions with the goal of reducing our emissions and Ontario is doing pretty well. And that’s mainly the result of one decision, and that was this decision started by a Conservative government and followed up by the Liberal government to shut down all the coal-fired electricity-generating stations. So Ontario has reduced greenhouse gases by 22 per cent at this point in time.”
At the municipal level, lessons have been learned that will make a difference for the future.
“(Last year) we had sand bags when required, we closed appropriate roads when required, we sent our volunteer fire department in to see who was in jeopardy and who wasn’t in jeopardy,” says Township of Muskoka Lakes Mayor Phil Harding. “We’ve never had a flood of this magnitude, so there’s always a little bit of new learning every time you go through a new situation. I truly believe that in Muskoka Lakes we managed it efficiently and effectively for the public. Nobody likes their road being closed, but we did what we could. Where possible on a couple of the roads we added some aggregate to raise the road surface a little bit – even six inches helped.
“The bottom line is, you’re never stopping water,” says Harding. “If it rains, if it snows, that water is coming through the system and nothing’s going to stop it. Our own staff are now better versed at looking further north in the system versus just in the south. That’s a better predictive model and generally speaking, it takes eight to 10 days for that water (that originates in Algonquin Park) to clear through the entire watershed.
As with most things, there is a need for balance in the Muskoka Watershed, taking into consideration what are at times competing interests. Perhaps Sale et al. say it best:
“As development increases in the coming years, it will be vital that land use planning take full account of natural capital if we wish to sustain our environment, quality of life, and vibrant tourist and recreational economy. It has long been recognized that Muskoka’s rich natural environment is a major driver of our economy, providing opportunities for healthful outdoor recreation and tourism throughout the year, so wishing to retain that is the obvious correct way forward.
“Our challenge over the next several decades will be to provide for needed development and enable population growth, while retaining this amazing natural environment and the quality of life we all enjoy.”