August 12, 2016

Continued Lack of Rain Causes “Severe” Drought Condition

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)

Based on the 30 Day Precipitation drought indicator, the Rideau River Watershed is in the “Severe” Drought category.

There has been no rain recorded at the Ottawa Airport since July 25. Some rain has been recorded at other locations in and around the watershed but there have not been the several days of rain needed to restore the deficit that has accumulated. There is rain forecast through Friday and Saturday but that is expected as thunderstorms which will not produce the needed general rain over the whole watershed. Warm weather is forecast to continue through next week which will cause losses to evaporation that will contribute significantly to the decline of water levels throughout the watershed.

This statement of “Severe” drought conditions is not a declaration of an emergency but an indicator of the severe dry conditions and impacts being felt across the Rideau watershed. Any declaration of an official state of emergency is a municipal decision.

Water levels in the Rideau Canal reservoir lakes, Bobs, Wolfe, Upper Rideau and Big Rideau, are about 30 centimetres below what are typical for this time of year. The lake levels now are what is usually seen in late September - early October on three of the lakes. Parks Canada staff have managed to keep water levels on Bobs Lake to what is typical for early September even though water has had to be released to maintain navigation in the lower Tay River, maintain habitat and to supply drinking water to the Town of Perth. However, both Upper and Big Rideau lake levels have fallen below the target operating range for early August. Nevertheless, Parks Canada has not yet had to reduce the maximum draft provision for the Canal system from Upper Rideau Lake through to the Ottawa Locks.

Levels on non-reservoir lakes have also continued to decline assisted to a large extent by evaporation of as much as 2.5 centimetres per day due to the recent 30 degree temperatures. Boaters on all lakes will need to be careful to avoid newly exposed shoals and rocks as levels drop.

Water conservation is increasingly important as the drought continues. Residents living in areas served by groundwater wells need to use water wisely to avoid depleting the aquifer from which they are drawing. Those whose water comes from a municipal water system need to check their municipal social media for any water use restrictions that may be in place. All residents are advised to check municipal social media for information on water use, water sources and, with groundcover and trees very dry, on fire bans. Holders of Permits to Take Water from surface or groundwater sources are encouraged to reduce their actual taking as much as possible.

Typical residential indoor water use breakdown across the United States and Canada is:

Toilet 24% Leaks 12%
Shower 20% Other 4%
Faucet 19% Bath 3%
Clothes Washer 17% Dishwasher 1%

* Source: Water Research Foundation, via Cataraqui Region Conservation Authority

Lawns that have turned brown from the drought are not “dead”. The grass has just gone dormant from lack of water. When rainfall returns, the grass will come out of dormancy and perk back up. In addition, it should be noted that lawns only require about 25 mm of water per week, any more than that can weaken the root system, making grass more susceptible to adverse conditions. Similarly, trees need 4 to 5 gallons of water once a week, even in drought conditions.

It should be noted that taking water from streams by pumping or in barrels or containers for watering gardens can impact other users as well as the ecological function of streams. Caution should be exercised with any withdrawals from surface water that the taking does not exceed inflow. It is not recommended to try fill dry wells with surface water or treated water. It would be better to fill cisterns or other storage units. Residents that have had their well go dry could check with their municipality which may have the capacity to provide drinking water from their water treatment plants, if they have one. If the well continues to be dry, a well driller should be consulted and deepening the well or having a new one drilled may need to be considered. For more information about wells, go to this MOECC site

To learn more about Ontario’s Low Water Response program visit their website.  Also, visit the RVCA website for information about drought response. For hourly and daily streamflows and water levels go to RVCA Flows and Water Levels section of the website.

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 1132.

Conservation Authority staff continue to monitor conditions and communicate with water managers throughout the watershed through the Rideau Valley Low Water Response Team. An update to this message will be issued as conditions warrant.

The Drought indicators are:

Minor: 80% to 60% of long-term average precipitation for 540 day and/or 90 day precipitation totals and/or 7-day average streamflows less than the 5 year return period low flow. This category reflects concern.

Moderate: 60% to 40% of long-term average precipitation for 540, 90 and/or 30 day precipitation totals and/or 7-day average streamflows less than the 10 year return period low flow. This category suggests a potentially serious problem is pending.

Severe: less than 40% of long-term average precipitation for 540, 90 and/or 30 day precipitation totals and/or 7-day average streamflows less than the 10 year return period low flow. This category indicates a failure of the water supply to meet demand.

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