Water management on local lakes

Jeff Green | May 03, 2012

A lot of people take an interest in spring weather. Gardeners wonder when they should put their peas in, or if they should start their tomatoes earlier. Road crews watch to see when the roads should be graded and whether half load rules should be relaxed. Local firefighters worry about hot dry weather in the early spring, as was the case this year. The dryness caused fire bans to be implemented (they have now been removed).

For Gord Mountenay, the water management supervisor for Mississippi Valley Conservation Authority, and for his colleagues at the Rideau Valley and Cataraqui Region conservation authorities, fall water levels, winter snow pack and run-off and spring rains are all factors that must be weighed before decisions about how to manage the water flows between the upper and lower lakes on the watersheds they manage are made.

“Rain and snow melt dictates whether we will have a flood, have water for recreation in the summer, or simply be able to manage the river in a way residents have become accustomed to,” Mountenay said in a recent communiqué about lower than average water levels in some of the upper lakes in the Mississippi system.

“Yet, water managers can’t make it rain when it’s needed or where it’s needed, nor can we stop it once there is enough, and only nature warms and cools temperature to affect the snowmelt. What we can do is recognize the changes in the weather and adapt our management practices where needed.”

With a minimal snow pack this year and lower than average rainfall last fall, Mountenay decided to begin holding water back on lakes in North Frontenac earlier than normal. With the warm weather in early April some cottagers were inclined to come to their cottage properties earlier than normal and Mountenay released a warning in mid-April that putting docks in earlier than normal is not a good idea because water levels were low on many of the lakes, and as levels rise with spring rain the docks could end up being under water.

“This spring in particular we are concerned about holding water in the upper lakes so we can ensure that Crotch Lake, which is the main reservoir lake for the Mississippi River system, is up to the level we need it to be at for recreation purposes in the summer season. We are always mindful that once water is removed from lakes it cannot be replaced except by rainfall.

“Generally speaking, putting a dock in before mid-May is not recommended. Water management from April through the end of May is focused on limiting high water and flooding, and moderating levels for wildlife habitat. During the high recreational use summer months, docks become part of the flood management priority, but this is not the case in the spring.”

MVC provides daily or weekly updates of water levels on Mississippi Lake and all other monitored lakes on its website at mvc.on.ca/water-management/mvc-water-levels. The site also provides information on stream flows and rainfall collected at monitoring stations across the watershed.