The protection of fish eggs is one of the major reasons Okanagan Lake wasn’t lowered sooner in the spring, Global Okanagan has learned.
To ensure the survival of wild fry in Okanagan River, downstream of Okanagan Lake, flow rates must be maintained at a certain level.
It’s a challenge that faced Shaun Reimer who determines release rates from the dam in Penticton.
In early spring, Federal fisheries asked Reimer to wait to discharge more water from the dam until sockeye eggs hatched downstream near Oliver.
“At this point we are more or less waiting for the fish to hatch because we have abit of a constraint for fisheries, particularly for the Okanagan River and the sockeye that spawn there,” Reimer said.
Either too much or too little water in Okanagan lake and Okanagan river can negatively impact both sockeye and kokanee fish eggs.
“The issues for sockeye are scouring as they are still eggs, so they won’t survive from that and for kokanee eggs it’s the lake levels,” said Howie Wright, Fisheries Program Manager with the Okanagan Nation Alliance. “They will be desiccated or dried out if the lake is drawn down too much.”
For Reimer it’s a delicate balancing act as he must release enough water at the dam to prevent lake flooding, but not too much to kill fish eggs.
“Once we really got into the middle of April I was getting a little more nervous because of the rains and again in consultation with DFO, ONA, I told them a lot of the fish had hatched at that point,” he said. “But I said I can’t wait any longer and in the third week of April is really when I started ramping up the flows to beyond even our design constraints here.”
The federal Department of Fisheries and Oceans said it asked Reimer to hold back the lake water to maintain compliance with the Okanagan Basin Agreement.
Spokesperson Kim Hyatt said it was impossible to predict the heavy rains and the accelerated snow pack melt that were to come.
“If we had known in the third week of April the levels of precipitation, temperature and melt rates that occurred in May, if there had been any way of knowing that and forecasting it, then the guidelines for protecting fish would have been set aside and Shaun would have increased the discharge level to the maximum that the system would bare at that time,” he said.
Reimer has come under criticism for not lowering the level of Okanagan Lake sooner in the spring.
He said he did the best he could with computer modeling information that didn’t predict flooding at the time, while trying to protect fish stocks.