(WCS-LW - 2/2021) July 6, 2021 — The Rideau Valley Low Water Response Team is maintaining a MINOR low water status for the Rideau River watershed after officials met to discuss dry conditions on Tuesday, July 6.
Watershed residents and businesses are encouraged to continue 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. There is less of a concern for residents of urban Ottawa because the City of Ottawa central drinking water system draws from the Ottawa River. Residents throughout the watershed should be aware of any bans or bylaws that may be in place in their municipalities regarding watering or fires bans.
Significant rain over the past few weeks has pushed 30-day rainfall totals above what is normal for the time of year at most climate monitoring sites in the region. However, the average 90-day rainfall measured at climate stations in and around the watershed is below 80 per cent of normal for this time of year which represents “Minor” low water severity. Stream flow values for all waterways are well below their normal values for this time of year but slightly improved from a few weeks ago. For example, the measured flows for the Rideau River at Carleton University and the Tay River in Perth are both near 45 percent of normal for this time of year. Measured flows for the smaller tributaries such as the Jock River and Kemptville Creek are still below normal for this time of year. Field observations around the watershed indicate that ecological conditions are declining with increased fragmentation of many streams. High water temperatures, low oxygen levels and increased plant growth and are being experienced in many areas.
Looking ahead, the seven-day weather forecast suggests we may receive between 35 and 45 mm of rain across the watershed. These rainfall amounts are not expected to greatly improve the 90-day rainfall deficit or the low stream flow values discussed above.
Following an early spring freshet this 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 slightly below normal and are expected to decline further with some precipitation in the short-term forecast. The water level in Christie Lake (flow-through lake), while expected to remain below normal, will fluctuate with some precipitation in the short-term forecast. Rideau River flows downstream of Big Rideau Lake have been reduced to minimum. Water levels in the Rideau River below Smiths Falls are within navigable ranges.
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.