The rise of flood waters on the Ottawa River is slow but continuing and is approaching the 1:10 year flood frequency*.

The slow rise of flood waters on the Ottawa River will continue today aided by runoff from the overnight rains. Levels had dropped yesterday on Lac Deschene but have risen again today. Downstream of Chaudiere Falls the rate of rise decreased slightly but that is likely to change with the impact of the rain.

The locations at risk of flooding on the Ottawa River within the jurisdiction of the Rideau Valley Conservation Authority are communities around Lac Deschene (e.g. Grandview Avenue and Britannia) and Boise Village east of Cumberland. There is an estimated 45 centimetres of water at the intersection of Morin Road and Ruelle Dubois in Boise Village that will limit access to homes in the neighbourhood. No reports of flooding have been received so far on properties on Lac Deschene.

On the Rideau system, Bobs and Christie Lakes remain high with some property flooding. With minimal rain in the 7 day forecasts, these lake levels can be expected to begin declining.

Levels on the Ottawa River can also be expected to decline but how quickly depends on what flows are received from further north in the watershed as the spring melt advances. Normally there is a lag between the high flows from the southerly tributaries and that from the upper parts of the watershed.

Spring water safety needs to be observed by all. In particular, children need to be warned of the dangers of cold and fast flowing waters

Conservation Authority staff will continue to monitor conditions and will issue an update on Monday, April 24.

For water level and flow information in the Rideau system as well as the Ottawa River, visit the RVCA Streamflows and Water Levels webpage.

For more information about conditions on the Ottawa River, also check the webpage of the Ottawa River Regulation Planning Board.

*1:10 year frequency is the flood level that has a likelihood of occurring of 10% in any given year.

The drought status in the Rideau River watershed that was left at “Minor” after a dry year in 2016 is, by this statement, reduced to “Normal”.

The uncertainty that prompted holding the Minor status through the winter was because it wasn’t clear what state groundwater resources had been left at as the onset of winter arrived. With a period of warmer temperatures and the loss of much of the snow cover by late March, there was an opportunity to access the monitoring wells in the Rideau River watershed. Measurements indicated that groundwater levels had been restored to about the long term average.

By this time in mid-April last year, farmers were able to get on their fields to start ploughing and planting. This year, flooding is still a concern and precipitation since the start of the year is 5% above normal. Dry conditions can at any time return, of course, and RVCA staff will continue to monitor conditions and issue statements as warranted.

All watershed residents are encouraged to conserve water at all times not just when drought conditions prevail.

Relevant information sources are as follows:

• Ministry of Environment and Climate Change 
• Ontario’s Low Water Response program
• Hourly and daily streamflows and water levels

In order that we can track impacts of the drought conditions in the watershed, we request that any individuals or businesses in the Rideau Watershed who may be experiencing difficulties with their wells please contact the Conservation Authority by calling 613-692-3571 or 1-800-267-3504, ext. 1128 or by email (instructions at http://www.rvca.ca/low_water/index.html ). There is also the Drought Impacts Map application on the RVCA website under Watershed Conditions.

As water levels and flows in the Rideau River watershed recede, levels on the Ottawa River have been rising.

Rain on Saturday and Sunday had little impact on stream flows anywhere in the Rideau watershed. Rain forecast for Wednesday and Thursday of about 30 millimetres can be expected to cause flows to rise by as much as 50 cubic metres per second on the Rideau. This will not be enough to bring on the return of flooding in those areas recently affected. Levels on three of the four Rideau Canal reservoir lakes have been declining very slowly but are sensitive to further rain presently being slightly below the Full Supply level. Bobs Lake has remained slightly above the Full Supply level because outflow has to be controlled to limit the impact downstream on Christie Lake. If the rain forecast does materialize, reservoir lake levels can be expected to rise slightly again.

The Ottawa River has been rising slowly over the last week as the many tributaries contribute their spring flows. There will be inflows passing through for several days as seasonal weather brings runoff from further north. The locations at risk of flooding on the Ottawa River within the jurisdiction of the Rideau Valley Conservation Authority are communities around Lac Deschene (e.g. Grandview Avenue and Britannia) and Boise Village east of Cumberland. There is already water on roads (Morin Road, Leo Lane) in Boise Village that can be expected to rise and limit access.

It continues to be risky to be around waterbodies. The water is still relatively high, fast moving and cold. Parents need to remind their children about the dangers.

Conservation Authority staff will continue to monitor conditions and will issue an update on Friday, April 21.

For water level and flow information in the Rideau system as well as the Ottawa River, visit the RVCA Streamflows and Water Levels webpage at http://his.rvca.ca/rvcafwl/ .

For more information about conditions on the Ottawa River, also check the webpage of the Ottawa River Regulation Planning Board at http://ottawariver.ca/river-levels-flows.php#river-levels-flows-7-days .

With access ways to the waterfront properties on the Long Reach of the Rideau River (Kars to Burritts Rapids) again passable, the Flood Warning, in place for the last week, is now reduced to Flood Watch. 

Rain forecast for Saturday evening into Sunday is expected to cause an upturn in flows in the Rideau system. However, flows are expected to have receded sufficiently by then that the increase will have a minor impact. The expectation is that flows, as measured at the recording station at Carleton University, will increase to about 280 cubic metres per second (cms) by early Monday. This is well below the peak flow reached on April 8 (456 cms) and below flows that would cause flooding to happen again.

The Rideau Canal reservoir lakes are all at their full supply level and measures are being taken to bring those levels down within the normal operating ranges for each of the four lakes. However, releases from each of the lakes has to be done to minimize the impacts downstream. Wolfe Lake has to be brought down in concert with Upper Rideau Lake and, in turn, Upper Rideau levels have to be managed within the limits of Big Rideau and Newboro Lakes. Releases from Bobs Lake have to be done with regard for levels on Christie Lake, flows in Perth and flows into Big Rideau and outflow from Big Rideau Lake has to be done with regard for levels on the Long Reach.

While flows are declining and temperatures are warming, it is still risky to be around waterbodies. The water is still relatively high, fast moving and cold so parents need to educate their children about the dangers

The Flood Watch will remain in effect through the weekend. Conservation Authority staff will continue to monitor conditions and will issue updates as warranted.

Water levels have been dropping throughout the Rideau watershed since Saturday but not all flooded areas are fully dry yet. Water levels have dropped about 22 centimetres since the Saturday peak on the Long Reach between Burritts Rapids and Manotick. Another 34 centimetres are left to go on Hilly Lane and similar amounts on the neighbouring waterfront communities near Kemptville. Until those communities have safe access restored, the Flood Warning will remain in effect.

The decline in levels in the Long Reach will be slowed by rain forecast for tomorrow and by water that has to be released from Big Rideau Lake to alleviate high water conditions on the Rideau Canal reservoir lakes. The release of water will be synchronized as much as possible with the movement of water through the Long Reach to avoid causing levels there to increase again.

Flood waters in and near Windsor Park and in Brantwood Park in Ottawa South and East have receded as have waters in the Richmond area on the Jock River.

It continues to be important for parents to advise their children of the dangers of cold and, in places, fast moving springtime waters. Everyone needs to be cautious.

Conservation Authority staff will continue to monitor conditions and will issue updates as warranted.

Runoff from the rain event on Thursday is working its way through the system leaving several waterfront communities still without access to their properties.

Water levels have been holding more or less steady for the last few hours. A definite peak has not yet been reached but can be expected today. Cooler temperatures overnight have slowed the runoff process. Temperatures of over 10 degrees forecast for today will cause much of the remaining snow and ice to melt and run off today which will keep levels up for the short term.

Once a definite decline of levels begins, Parks Canada staff will need to begin releasing water from the reservoir lakes upstream of Smiths Falls to relieve high levels on the lakes. Every effort will be made to keep the release close to the rate of decline on the Long Reach between Burritts Rapids and Manotick to avoid increasing water levels again in the communities first hit on Thursday.

Water levels on the Jock River rose through Friday causing some properties in and around Richmond to have access issues and their sump pumps running. Flooding in Ottawa South adjacent to and in Windsor Park and in Ottawa East in Brantwood Park has closed the streets and park pathway.

Weather forecasts call for 10 millimetres of rain on Tuesday and continued warm daytime temperatures. The warm temperatures will continue to take the frost out of the soil and melt the last stubborn snow and ice in sheltered areas. The rain is likely to slow the rate of recession of water levels for a brief time.

As with all of these messages, we want to emphasize the need for caution near the cold and, in some places, fast moving water. Parents need to make their children aware of the danger.

Conservation Authority staff will continue to monitor conditions and will issue updates as warranted.

Heavy rain on Thursday has caused streamflows and lake levels to increase significantly in the Rideau River watershed.

The amount of rain that fell in eastern Ontario wasn’t quite as much as forecast but it is certainly having an impact. Such water levels were last reached in 2014. The worst impact is in North Grenville and rural Ottawa near the confluence of Kemptville Creek with the Rideau River.
Some street and pathway flooding is occurring in Ottawa South adjacent to and in Windsor Park and in Ottawa East in Brantwood Park. No residential flooding in urban Ottawa has been reported to the RVCA.

With only light rain showers still in the forecast and runoff has been working its way through the system, the rate of increase of water levels has begun to slow down. Peak flow can be expected to occur tonight or early Saturday at about 450 cubic metres per second as measured at the monitoring station at Carleton University.

The recession will continue through the weekend. However, there may be a reversal on Monday as Parks Canada staff release water held in the Rideau Canal reservoir lakes that has been held back to provide some peak flow attenuation. This influx of water is expected to slow the recession briefly.

Everyone, especially children, are advised to stay away from the fast flowing and cold water in watershed streams. Also, there may still be ice on some more sheltered lakes that can be expected to be highly unstable and should be avoided.

Conservation Authority staff will continue to monitor conditions and will issue updates as warranted.