I wanted to share a brief status update on the Spring Freshet efforts to date, as a way to keep you informed. The City’s Public Works has established a Task Force for the monitoring and response to river flooding associated with the freshet. The 2024 freshet season began with an early local melt, warm temperatures, and periods of slightly elevated water levels.
It is common for the Ottawa area to experience an early melt which affects levels and flows on local rivers such as the Rideau, Castor, South Nation, etc. As you know, the snowpack in the Ottawa area has been depleted. As such, the risk of significant flooding for residents along the Rideau River and smaller rivers related to the local spring melt is quite low at this time. The Freshet Task Force is committed to ongoing monitoring and will provide relevant updates should alerts be issued by our local Conservation Authorities.
In relation to the Ottawa River, the Task Force continues to monitor snowpack, and weather forecasts across the larger catchment area. Despite the early rise in water levels, the controlling water management partners are attempting to mitigate potential drought conditions with potential flood risks. From a flood perspective, it has been helpful that several forecast precipitation events have occurred over the past few weeks which were less impactful than some models had suggested. Similarly, the recent return to seasonable temperatures had slowed the melting of the northern portion of the Ottawa River catchment area and resulted in rivers to return to more seasonable levels. We expect to see the Ottawa River responding to the melting of snow in northern portions of the catchment area in the coming weeks.
Please note the following segment of the Early Spring Conditions Overview of the Ottawa River document published by the ORRPB:
As of March 13, the amount of water in the snowpack is well below average across the basin. This reduced snowpack combined with the forecast of no significant precipitation event over the coming week is prompting reservoir operators to carefully manage the transition from drawdown to refill to help reach summer levels while still reducing flooding risks.
Although it is too early to forecast the magnitude and timing of the peak on the main stem of the Ottawa River, the ongoing slow melt of the snowpack in the central portion of the basin could constitute a mild start of freshet. However, it is not possible to completely rule out the occurrence of flooding this early in the year. Weather conditions over the coming weeks (such as additional snow falls and heavy rainfall events) will influence the strength of the freshet. Often, these weather conditions only become certain a few days in advance.
Looking ahead, the Freshet Task Force will continue to monitor river levels and snow conditions across the larger catchment area. I encourage residents who are interested to visit the Flooding | City of Ottawa and Water pooling and flood control | City of Ottawa webpages for updates and links to the Ottawa River Regulatory Planning Board and local Conservation Authorities for up-to-date information on water levels, Water Safety Statements, and forecasts.
