(WCS-LW - 1/2023)
July 11, 2023 – Following a period of dry and hot weather, the Rideau Valley Low Water Response Team is declaring a MINOR low water status for the Tay River and Rideau Lakes watersheds (referred to as Upper Rideau Valley watershed), after officials met to discuss current watershed conditions on Monday, July 10, 2023.
Upper Rideau Valley watershed residents and businesses are encouraged to voluntarily reduce their water usage by 10 percent. This is especially important for those who have permits for taking water from surface or groundwater sources and all residents on private, communal or municipal wells. The requested voluntary water use reduction does not apply to residents of urban Ottawa because the City of Ottawa central drinking water system draws from the Ottawa River. All residents throughout the Rideau Valley watershed should be aware of any bans or bylaws that may be in place in their municipalities regarding watering or fire bans.
Over the last couple of months, rainfall amounts have been quite variable across the Rideau Valley watershed with some areas receiving above normal precipitation (urban Ottawa) but many other areas receiving limited rainfall. In general, the average 90-day rainfall measured at climate stations in the upper Rideau Valley watershed has been below 80 per cent of normal for this time of year which represents “minor” low water severity. Stream flow values for all regulated waterways (augmented from the reservoir lakes in the Tay River watershed) range from 60 to 70 per cent of normal for this time of year. Natural system stream flow values range from 30 to 50 per cent of normal for this time of year.
Parks Canada staff are closely monitoring the water levels throughout the Rideau Canal system inside the Rideau Valley watershed. The water levels in the reservoir lakes (Bob’s Lake and Wolfe Lake) are currently well below normal and are expected to decline further unless significant precipitation is received soon. Rideau River flows downstream of Big Rideau Lake have been reduced to minimum when possible. Water levels in the Rideau River below Smiths Falls are within navigable ranges.
Looking ahead, the seven-day weather forecast suggests we may receive up to 25 mm of rain across the watershed. If received, these rainfall amounts would slightly improve the 90-day rainfall deficit and the low stream flow values discussed above if the rainfall is distributed across all areas of the watershed.
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.
Ministry of Environment, Conservation and Parks: https://www.ontario.ca/page/ministry-environment-conservation-parks
Ontario’s Low Water Response program: https://www.ontario.ca/page/low-water-response-program
RVCA website: www.rvca.ca
Hourly and daily streamflows and water levels: https://www.rvca.ca/watershed-monitoring-reporting/reporting/streamflow-water-levels
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Rideau Valley Conservation Authority is a partnership of municipalities within the Rideau Valley watershed
created under the Conservation Authorities Act to deliver a range of programs in watershed management and
natural resource conservation.