APRIL 18, 2019 OTTAWA RIVER FROM ARNPRIOR TO HAWKESBURY — Rideau Valley Conservation Authority (RVCA) in conjunction with the Mississippi Valley (MVCA) and South Nation Conservation Authorities (SNC) is issuing an update FLOOD WATCH for the areas under our jurisdiction along the Ottawa River.
The Ottawa River Regulating Committee warns that levels and flows on the Ottawa River from Lac Coulonge down to the Montreal region are expected to rise extremely rapidly starting this Friday due to forecast rainfall and snowmelt runoff. Major flood levels are expected to be exceeded over the weekend. Later on, flows and levels similar to those observed at the height of the May 2017 flood may be reached depending on the amount of precipitation received. All flood-prone areas along the Ottawa River from Lac Coulonge down to the Montreal Archipelago are at risk.
River Conditions Forecast / Flooding Risk: Two low pressure systems are expected to bring 30 to 80 mm of precipitation over much of the basin from Thursday through to Saturday. At the same time, warmer temperatures will melt a large portion of the remaining snowpack in the central areas of the basin. Rainfall and snowmelt will combine to produce very high runoff, causing levels to rise sharply on the Ottawa River starting this Friday. Levels are expected to exceed major flood levels, which are the levels at which several houses are impacted, over the weekend in flood-prone areas along the Ottawa River. Levels as high as those seen in May 2017, at the height of the flood, could be reached depending on the amount of precipitation received. Due to the forecast uncertainty it is difficult to accurately predict how quickly water levels will rise and when river conditions may peak. Residents of flood-prone areas are encouraged to closely follow evolving conditions and to take necessary measures. The Regulating Committee will be reassessing forecast conditions and providing hydrological condition updates on its website daily at http://www.ottawariver.ca/forecast.php .
Residents are advised to stay away from watercourses where flows are high and where banks might be unstable. Parents are encouraged to explain these dangers to their children.
This FLOOD WATCH statement is valid through April 20, 2019. Additional statements will be issued when or if conditions are expected to change significantly from this outlook.
"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."
RVCA Watershed Conditions Statements:
- Water Safety – High flows, unstable banks, melting ice or other factors that could be dangerous for recreational users such as anglers, canoeists, hikers, children, pets, etc. Flooding is not expected.
- Flood Outlook – Early notice of the potential for flooding based on weather forecasts, calling for heavy rain, snow melt, high winds or other conditions that could lead to high runoff, cause ice jams and/or lakeshore flooding or erosion.
- Flood Watch – Flooding is possible in specific watercourses or municipalities. Municipalities, emergency services and individuals in flood-prone areas should prepare.
- Flood Warning – Flooding is imminent or already occurring in area watercourses.