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October 05, 2016

Erratic Rains means “Severe” Drought Condition Continues

The drought status in the Rideau River watershed remains at “Severe” because sustained flows in the streams and rivers have not been restored.

As has been the case all summer, rainfall has been very erratic with significant amounts recorded at some monitoring stations and very little at others. There has been enough rain in the last two weeks to make many watershed residents forget that there is still a drought. Lawns are green. Farm crops are close to being ready for harvest.

But small streams are still dry and larger streams still have disconnected pools with little to no flow in between. The recent cooler temperatures have slowed evaporation and cooled the pools which increases the water’s ability to hold dissolved oxygen. Unfortunately, the fish, reptiles and amphibians that would benefit from these cooler waters have died off or migrated to more favourable habitats.

The level of Big Rideau Lake is at the winter target almost two weeks early and still trending down. Bobs Lake has 11 days and about 6 centimetres to reach the winter level. To add to a complicated year of water management, Parks Canada staff are faced with providing sufficient water for trout spawning in Big Rideau and Bobs Lakes. Dewatering of the lower reaches of the Rideau Canal for the winter will begin after Thanksgiving Day.

Along with the four Canal reservoir lakes, levels on the other lakes in the watershed have also declined making navigation difficult.

All watershed residents are encouraged to continue to conserve water. With the onset of autumn, gardens will not need as much watering as previously and what may be needed could come from rain barrels. Cars, driveways and houses still do not need to be washed.

Until it is obvious that sustained flows and levels have been restored and the Rideau system is recovering, the “Severe” Drought designation will continue to apply. The drought status will be reviewed regularly and amended as conditions warrant.

Relevant information sources are as follows:

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

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.