While many have been lamenting the wetter than usual spring, it is helping greatly with the Comox Valley Water System.
Due to all the recent rain, BC Hydro is updating its forecast for the Puntledge River summer water supply.
“What a difference five weeks can make,” BC Hydro spokesman Stephen Watson, in a press release. “Since the beginning of April, with the wet and cooler weather, the water supply forecast for the summer has improved with a snowpack that is nicely above normal. This bodes well for Puntledge River system fish habitat flows, domestic water supply, recreation and electricity power generation.”
After drier than usual months of February and March (46 and 66 per cent precipitation rates, respectively) the wet month of April (188 per cent) and continued precipitation in May are promising for the Comox valley Water System supply.
“Our April forecast for the February to September period was about 89 per cent of normal inflow volume into the Comox Lake reservoir, but with our updated May forecast, it is now 94 per cent of normal,” said Watson. “The residual May to September forecast is showing at 108 per cent of normal. This is good news.
The Comox Lake Reservoir is currently at 132.65 metres and that’s below normal for this time of year. The cooler weather has limited the water inflows into the reservoir during the recent wet period.
As the weather warms up the freshet will begin and BC Hydro plans on having the reservoir full by June. The reservoir level may annually fluctuate over the year from about 131 metres to around 135.3 metres.
The Puntledge River flow rate below the Comox Dam is about 30 m3/s with the powerhouse running at full capacity.
“That flow rate will likely hold into the summer and then we’ll adjust downward as we follow the lead of the weather conditions and naturally declining inflow,” said Watson. “Depending on how quickly the snow melts, and rainfall during the rest of the spring, there may be a chance of spilling extra water to control the reservoir level.”
That timing may be good as Fisheries and Oceans Canada have initiated discussions about potential extra water releases in June to assist with the chinook salmon smolt out-migration to the ocean, and the Vancouver Island Whitewater Paddling Society is looking at a modified Puntledge River Paddle Festival event around the end of May or June. BC Hydro will provide community river safety notices of higher than normal flow rates should these activities take place.”
In looking at the extra water releases, if needed, and the overall updated water supply forecast, BC Hydro is currently forecast being able to stay above the minimum Puntledge River fish habitat flow rate of about 16 m3/s below the powerhouse through the summer.
“For the first time in five years, it’s nice to have a good water supply forecast for the summer versus drier than normal conditions,” said Watson.