BC Hydro braces for series of coastal storms
A series of storms are forecasted to hit the region over the next week. As well, the ocean tides next week will be high and challenging for flood risk management operations.
There are two significant tropical storms for next Monday-Tuesday and Wednesday-Thursday with a precipitation totals of around 200 mm over those four days. Daily inflows into the Comox Lake Reservoir are forecasted on Tuesday to be around 170 m3/s, with hourly peaks up to 400 m3/s.
The high ocean tides for those four days will be around 5.0 metres. It appears there may also be some ocean storm surge from winds from these storms.
Given the Browns River and Tsolum River are forecasted to increase significantly next week over multiple days, BC Hydro will engage in an operations to decrease the discharge to low levels from Comox dam during the high tides, and increase the discharge to high rates during low tide. This means the Puntledge River may have high swings in flows.
Discharges from the dam may vary from about 35 m3/s to about 200 m3/s to control the reservoir level and consider downstream flood risk.
In advance of these storms, BC Hydro will be releasing more water from the Comox dam to allow more room in the reservoir to potentially absorb the forecasted water inflows next week. Flows from Saturday through Monday may be around 110 m3/s. The reservoir is currently at 133.95 m and slowly dropping. Water begins to free-spill over the dam at 135.3 metres. The reservoir can easily go up one metre in 24 hours under high storm water inflows.
The public is advised to stay away from the Puntledge River from today through next week.
Flooding in the Courtenay River can generally begin at around 400 m3/s, but this is influenced by ocean tides and potential ocean storm surge from winds.