2007 Rideau Watershed
Spring Runoff – Long Range Outlook
The Rideau Valley Conservation Authority issues the Long Range Outlook bulletin at the beginning of March each year to provide an indication of the potential for flooding when the spring freshet occurs. Historically, freshet occurs between mid-March and mid-April in the Rideau Valley.
RIDEAU VALLEY, March 9 , 2007 — Based on present snow conditions on the Rideau Watershed and assuming that there will be normal precipitation amounts over the next several weeks, the Rideau Valley Conservation Authority (RVCA) is presently expecting below average spring flow conditions this year.
There was no real accumulation of snow on the ground in the Rideau watershed until mid-February. The snowpack is very light with low water content. The RVCA most recent snow measurements were completed on Thursday, March 1st, when the snow depth was close to the long-term average, but the water equivalent of the snowpack, at 33 millimetres, was only 50 percent of the long term average. The storm on March 2nd added 15 to 20 centimetres of new snow on the ground, but the increased water equivalent in the snowpack remains well below the long term average for March 1st.
The RVCA is now in the daily planning cycle of its flood forecasting and warning operations – weather forecasts are being monitored and estimates of expected river flows and water levels are being prepared on a daily basis. Flood advisory or warning messages will be issued as required based on those forecasts.
Everyone living near a watercourse should inform themselves of the flood risks in their area and should review their own plans for minimizing flood-related property damages and inconveniences.
Municipal officials should review their flood response plans at this time and the usual preparations should be made to respond to emergency situations as required.
The role of the Conservation Authority is to provide early warning of a developing flood situation and continuous monitoring and analysis throughout the event. Timely and useful information will be provided to municipal and provincial emergency response personnel on the expected severity and duration of the event.
Recent cold temperatures will have caused ice cover to become thicker throughout the watershed, but everyone is advised to be cautious around watercourses. Please supervise children and make them aware of the danger of unstable ice and increasing flows as the spring thaw progresses.
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Patrick Larson, Senior Water Resources Technician
Rideau Valley Conservation Authority
613-692-3571 ext. 1110