BC Hydro - Puntledge River System Update
December 3, 2015
From BC Hydro - December 3, 2015
Since Tuesday, BC Hydro has been following a series of moderate to heavy storms hitting the Puntledge River watershed. This current storm has been heavy and the forecasted Saturday-Sunday and Monday-Tuesday storms will also be heavy in terms of rainfall. And the longer range forecast into next week there is the potential for a couple more substantial storms. Since Tuesday, about 190 mm of rain has fallen in the upper watershed. Cumulative precipitation from now through Tuesday may add another 200 – 300 mm to that total. The freezing level is currently around 1600 m for the current storms and may potentially rise to 2000 m early next week.
This morning was very close in terms of flood risk management. For the morning high tide, we reduced our discharge from the Comox dam from 65 m3/s to 25 m3/s, including shutting down the generating station. The Browns River and Tsolum River remain high and are currently at about 110 m3/s and 200 m3/s respectively.
The storm surge from the winds pushed up the estuary and created a high tide of 4.8 metres this morning to be nearly 5.3 metres.
We have been working closely since early this morning with the City of Courtenay on the storm situation and will continue do so into next week.
The forecast of continued wet weather and major water inflows into the Comox Lake reservoir will, as the days go by, diminish our downstream flood risk management operations. From tomorrow onward, we will reduce our discharge from the Comox dam down to 50 m3/s at high tides, and go back up to 160-200 m3/s when the tide is moving out. Our two Comox dam spillway gates are now wide open given the tide is receding.
The current water inflow into the reservoir is around 300 m3/s. The reservoir has been going up 6 cm per hour, and the rate of rise will depend on inflows and the discharge out of Comox dam.
BC Hydro will provide an update tomorrow afternoon. For public safety, in consideration of the high flows and some debris in the river, please stay away from the Puntledge River through next week.