Severn Flooding Updates

April 15, 2008

To offer some context on the numbers that will appear in this space over the next several weeks, the record flow level for the Black River in 1998 was 218 cubic metres per second. The flow of the Severn River was also 218 cubic metres per second.
During the flooding period in 1998, the flow from Lake Simcoe was completely cut off. So, it was solely the flow of the Black that brought the flow to 218 cubic metres per second on the Severn, causing the flood.

April 15:
The water flow of the Black River is down. It was flowing at 180 cubic metres per second on April 13 and it’s down to 169 cubic metres per second today.

However, officials are saying it’s premature to say that the Black River has peaked. Below freezing temperatures during the last two nights have contributed to this leveling off and there are still reports of considerable snow in the headwaters of the Black River. The expected warm temperatures this week will cause the snow to melt, possibly elevating flows on the Black River.

Last week, after some of the dams were closed in Washago, there was still 30 cubic metres per second of water coming through from Lake Simcoe. When they closed the valve at Lock 42 on the weekend, the flow slowed to about 15 cubic metres per second.

Due to the decline in levels on the Severn River and Sparrow Lake, the Trent-Severn Waterway is re-opening the valves at Lock 42. Residents on Sparrow Lake and the Severn River, below the lock, should expect water levels to rise, as a result.

Water levels on Lake St. John continue to be high as a result of the high flows on the Black River and the Ministry of Natural Resources anticipates this to continue through the foreseeable future until the Black River drops.