RVCA maintains a local Flood Forecasting & Warning System as part of a province-wide program administered by local conservation authorities, the Ministry of Natural Resources and Forestry and other stakeholders.

Our goal is to reduce danger to people and property by providing local agencies and the public with advanced notice, information and advice about imminent flooding risks so they can respond to potential quickly and effectively to the situation.

The RVCA uses stream gauges, weather stations, snowpack surveys, meteorological forecasts and computer models to determine the potential for flooding. When spring melt or severe storms are anticipated, the Conservation Authority estimates the severity, location, and timing of possible flooding, and issues alerts.

The RVCA’s Flood Forecasting program includes the entirely of the Rideau Valley watershed, and co-ordinates with the Ottawa River Regulation Planning Board and neighbouring conservation authorities MVCA and SNC to issue joint alerts for the Lower Ottawa River between Arnprior and Hawkesbury.

The RVCA also co-ordinates the Rideau Valley Low Water Response Team [link to low water page] in times of drought.

The provincial Conservation Authorities Act grants us the responsibility and obligation to direct development away from low-lying areas beside a water channel, known as the floodplain. We do this to protect people and property from damage or loss from flooding. The Act came into force in 1946, although the RVCA wasn’t created until 1976.

We also have a responsibility to protect wetlands, streams and tributaries from development, interference and alterations, which means projects like dock installations, shoreline repairs and some landscaping could require permits to protect the nearby waterway from contamination or damage.

We never know exactly, nor by how much. But our staff includes highly-trained engineers, hydrologists, technicians and GIS experts who use past and current data to model and predict how water levels and flows may change under certain conditions. Historical data is used to model the river and its tributaries to develop floodplain mapping for floods that statistically take place every five, 10, 20, 50 or 100 years. Using current conditions and forecasted weather, we can estimate how serious we think flooding may become and inform the public. Snow pack measurements, rainfall and temperature all play a role in calculating the risk of spring flooding.

We provide the best possible information we can based on the best science we have to help you protect you and your family from flooding danger.

Our estimates are based on the best available scientific information about the shape of the valley, soil conditions, current weather conditions and how these factors help predict the likelihood of flooding. They remain estimates, however, and they are not 100% accurate. Neither is human memory.

Yes, and many are! Provincially, Ontario has some of the most extensive flood mapping in Canada, because of the unique existence of conservation authorities and their flood management mandate.

The RVCA now has floodplain mapping on more than 1,000 km of waterways in its watershed, focusing on developed areas. Each year more maps are created or updated in a continuous cycle of improvement. This work is limited only by time and funding. Since 2012, additional funding from the City of Ottawa, and more recently the federal government, has allowed local conservation authorities to ramp up their mapping efforts even more.

Parks Canada is responsible for managing water levels on the Rideau Canal, and they do lower levels in the fall to make room for winter and spring runoff. Bobs and Christie Lake are reservoir lakes but, being in the upper watershed, they don’t catch any water that enters the system downstream, where storage capacity is low.

The beautiful historic dams along the Rideau are mainly for controlling navigation levels, not flooding. Enough water from melting snow and rain in the spring will cause flooding despite using the dams as best we can to disperse the water.

Parks Canada also can’t use its locks to release water in the event of a flood. Canal infrastructure is nearly 200 years old in some places, and the bottoms of the locks aren’t protected against erosion. Sending a rush of flood water through them could be very damaging.

For more details, please contact Parks Canada at the Rideau Canal Office (613-283-5170).

No one – and no one is purposefully directing water away from one community toward another, either. The fact is, you can’t fully prevent flooding. It’s a natural and important part of a healthy river system, which is why the waterway AND its floodplain are considered part of the river. Conservation authorities mitigate the risks to people and property through a mix of floodplain mapping, monitoring, infrastructure upkeep and development regulations.

In fact, Ontario’s 36 conservation authorities have done such a good job keeping new development out of the floodplain, they’ve made their greatest benefit nearly invisible: new communities rarely flood, so their residents may not even recognize the potential danger they’ve avoided.

Flooding is a natural process, and humans must respect a river’s need to contract and expand with the seasons. But we can build natural flood resilience into our environment by supporting healthy forests and wetlands. These areas absorb rain and snowmelt and then slowly release it into waterways over a long period of time. Without forests and wetlands, intense rain and snowmelt would rush directly into already swollen lakes and rivers, making flooding worse.

When images of flooding are fresh, it’s easier to remember the importance of what conservation authorities do, but we need strong public and political support for our work long after the flood waters recede.

In the end, we must all work together to create communities where people and their homes are protected against damaging floods.