August 02, 2018

Record Rains Improves Low Water Condition in Rideau River Watershed

For more information, contact:

  • Patrick Larson
  • RVCA Senior Water Resources Technician
  • 613-692-3571 or 1-800-267-3504 ext. 1210
  • 613-799-9423 (cell)

August 2, 2018 –  This statement is to advise that the low water status in the Rideau River watershed has been reduced to Minor Severity.

Longer range forecasts indicate warmer and dryer than normal through the rest of the summer and into the fall. If that forecast comes to pass, flows and levels can be expected to fall well below normal. Present conditions are generally close to normal but because of declining flows and forecasts, the low water status is being reduced from Moderate to Minor Severity rather than being withdrawn entirely.

Record rainfall was measured at several climate monitoring stations in eastern Ontario through July 21 – 28. Forecast amounts were exceeded throughout the Rideau watershed. The result was streamflows above the historical averages for the time of year in most cases.

However, flows are declining again and can be expected to descend below average once more with limited rain forecast and days with 30 degree temperatures causing evaporation. Except for Bobs Lake, the Rideau Canal reservoir lakes are 10 to 20 centimetres below targets at levels scheduled to be reached by late September. Bobs Lake, presently about 10 cm below the rule curve, is at levels expected to be reached by a week and a half into August. A better indicator may be the long term historical averages which reflect how difficult it is to maintain lake levels to a prescribed elevation. This summer, levels on all of the reservoir lakes have been typically below the historical average.

Kemptville Creek has responded little to the rainfall. Smaller tributary streams are again going dry after brief increases. The Creek itself has flows about 6% of normal measured downstream of Oxford Mills compared to, for example, the Jock River at twice normal for the time of year. With such flows that are occurring in the Kemptville Creek sub-watershed, habitat for fish and other aquatic creatures is diminished and populations are likely to be affected.

The full impact on agriculture of the kind of conditions presently being experienced in the Rideau watershed is never known until the crops are harvested. How well each crop does depends entirely on timing and quantity of rain and heating temperatures.

Water conservation should be practiced by everyone within the Rideau River watershed. Use of rain barrels to capture water for lawns and gardens, avoiding using pressure washers to clean houses, driveways, decks and fences are actions that contribute to the conservation of our water resources. Municipalities may have invoked water restrictions so check your municipal website for applicable bylaws. Those who have permits for taking water from surface or groundwater sources are encouraged to reduce their actual taking as much as possible.

Conservation Authority staff continue to monitor conditions and communicate with water managers throughout the watershed. Updates to this message will be issued as conditions warrant.

Other relevant information sources are:

Ministry of Environment and Climate Change:

Ontario’s Low Water Response program:

RVCA website:

Hourly and daily streamflows and water levels: .



Contact Us

Rideau Valley Conservation Authority
3889 Rideau Valley Drive
Manotick, Ontario K4M 1A5

613-692-3571, 1-800-267-3504



Regular Hours: Monday to Friday, 8:30 a.m. to 4:30 p.m.

Member of: conservation ontario