Dear editor,

I would like to respond to a recent letter entitled BC Hydro has an obligation to keep the reservoir full (Sept. 19) to explain the challenges we experienced 2015 and the decisions that were made to balance various water use interests.

2015 was an especially challenging year for BC Hydro in managing water levels in the Comox Lake reservoir and flows in the Puntledge River. There was a record low snowpack, which resulted in little spring freshet at a time when we were already releasing minimum fish habitat flows. That flow release only allows for a small amount of power generation. We conserved water as the dry trend unfolded, and managed to have the reservoir essentially full in April. Each year we aim to have the reservoir full in June.

With late spring and summer water run-off into the reservoir very low, further water conservation was required. This included shutting down the generating station in June and eventually moving to a Puntledge River flow of just 8.5 m3/s, or about half the minimum fish habitat flow of 15.6 m3/s. Thankfully a large rain event in September got us into a better situation that year.

Could a similar situation happen again with a very low snowpack? Yes, and when that occurs, as we do every late spring, BC Hydro will try to have the reservoir full so we can manage through the summer and early fall the best we can with the water provided for fish, domestic water supply, power generation, and recreation. Our main priority during conservation periods is releasing water into the river for fish.

This year we also had some record dry months from February to June but the snowpack, though below normal, was a lot higher than 2015 thanks to the colder winter. Some above-average rains in the July-September period helped to carry us through to the early fall. We update our water supply modelling each year.

Stephen Watson,

BC Hydro