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Notice: Watershed Conditions Statement - FLOOD WATCH/OUTLOOK Updated Nov. 3

Rideau Valley Conservation Authority - Watershed Conditions Statement – Flood Outlook, Rideau River

November 3, 2017 –  Rain forecast for Sunday could raise water levels again.  In the order of 25 to 30 millimetres of rain fell on the Rideau watershed yesterday and this morning, less than was forecast. The rain was not enough to raise water levels significantly.Rain now forecast for Sunday has the potential to be enough to raise the already elevated flows. Ministry of Natural Resources and Forestry meteorologists have forecast 10 to 25 mm of rain on Sunday which could increase to a total of 40 to 75 mm if thunderstorms occur on Sunday night. The result could be localized with increased flows confined to small areas. Or the rain could fall more generally throughout the watershed which again raises the possibility of flooding low-lying areas that have already been affected in the Long Reach.

Flows in Kemptville Creek have continued to rise despite adjustments to the Oxford Mills Dam. Present flows are below typical spring flows but are ten times the normal for this time of year.

Residents are advised to stay away from rivers as the forecasted weather may rapidly increase river flows, and cause slippery river banks.  Parents are encouraged to explain these dangers to their children. 

November 2, 2017 –  Water levels that were already high from rain on Sunday and Monday are expected to increase again if rain forecast for Thursday and Friday falls on the Rideau River watershed.  About 12 millimetres (mm) of rain fell overnight and as much as 40 mm more is expected. This could cause flows in the Rideau below Mooney’s Bay to increase to about 320 cubic metres per second. While not an issue in the lower sections of the system, such flows typically mean flooding of low-lying areas on the Long Reach, the section of the river between Manotick and Burritts Rapids, with the access roads to the river side communities at risk.

October 30, 2017 –  Rainfall over the last three days from 70 to 100 millimetres has caused water levels typically seen in the spring in the Rideau watershed.  

Flows rose dramatically from what they were going into the weekend after very little rain through September and most of October.

Operation of the Long Island Dam by Parks Canada staff slowed the increase of levels on the Long Reach. However, access roads to communities on the Rideau near Kemptville may still be threatened as the water from upstream passes through the system.

In Perth in the Tay Subwatershed, flooding has so far been limited to Stewart Park. Adjustments will be made as required at the construction site at Haggert Island Dam to accommodate increased flows.

Possibly those most affected by the heavy rains may be the farming community. With significant standing water left in fields, farmers may have difficulty removing the remaining crops. Rain forecast over the rest of the week will continue to cause problems getting on the fields.

The additional rain into next weekend can be expected to slow the recession of waters in streams such as Steven Creek. Residents in North Gower can expect to see the banks close to full through to next week.

Residents are advised to stay away from rivers as the forecasted weather may rapidly increase river flows, and cause slippery river banks.  Parents are encouraged to explain these dangers to their children.

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: https://www.rvca.ca/watershed-monitoring-reporting/monitoring/surface-water-quantitiy

More Information:
Patrick Larson, RVCA Senior Water Resources Technician 
Rideau Valley Conservation Authority 
613-692-6831, 1-800-267-3504 ext. 1210

RVCA Watershed Conditions Statements:

  • Water Safety – High flows, unstable banks, melting ice or other factors that could be dangerous for recreational users such as anglers, canoeists, hikers, children, pets, etc. Flooding is not expected.
  • Flood Outlook – Early notice of the potential for flooding based on weather forecasts, calling for heavy rain, snow melt, high winds or other conditions that could lead to high runoff, cause ice jams and/or lakeshore flooding or erosion.
  • Flood Watch – Flooding is possible in specific watercourses or municipalities. Municipalities, emergency services and individuals in flood prone areas should prepare.
  • Flood Warning – Flooding is imminent or already occurring in area watercourses.

South Nation Conservation Watershed Conditions Statement – Flood Watch

Rain gauges within the region have recorded between 50 and 100 mm since October 29, 2017.  Environment Canada is forecasting an additional 20 mm of rainfall for today and an additional 10 to 15 mm for the remainder of the week.

Water levels are expected to increase, which may cause flooding in low lying areas. In addition, some access roads may need to be closed due to flooding.  There is also potential for blocked storm drains, catch basins and culverts which may also cause localized flooding.

Residents are advised to stay away from rivers as the forecasted weather may rapidly increase river flows, and cause slippery river banks.  Parents are encouraged to explain these dangers to their children.

SNC will continue to monitor the water levels and weather forecasts as part of the Flood Forecasting and Warning Program and will provide updates as conditions change.

The public is encouraged to visit www.nation.on.ca and to also provide feedback with respect to changes in water related conditions in their local areas. All feedback can be sent to , posted on our Facebook (/SouthNationConservation), or Tweet us your photos (@SouthNationCA). 

For more information, please contact Michael Jones at 1-877-984-2948 ext. 310 or Omar Kana’n ext. 309

This statement is in effect until Friday, November 3, 2017.