BC Hydro is lowering flows along the Puntlege River, starting tomorrow.
The river’s flow will drop from 14 to 12 cubic metres per second.
Despite above-average rainfall in July, inflow into the Comox Lake Reservoir has been about 44 percent of its normal total, given the depleted snowpack.
Power generation will be shut down with the revised river flow rate.
BC Hydro spokesperson Stephen Watson said that over the past decade there were three other years where BC Hydro reduced power generation to zero to conserve water.
“It is not uncommon,” Watson said.
The amount of water from the penstock that would normally pass through the powerhouse will be redirected down the Barber’s Hole, Nymph Falls and Stotan Falls sections of the river.
The river flow rate in these locations will rise from about six to 12 cubic metres per second, which is twice the normal flow rate.
“We are providing a safety caution for people that enter the river in these areas. Temporary public safety signage will be placed along this stretch of river, from the Puntledge River Diversion Dam to the powerhouse,” Watson said.
“The rest of the river system will remain with low water conditions. For tubers, it will mean shallower water level conditions as people float down the river.”
The minimum fish habitat flow is 15.6 cubic metres below the powerhouse.
“On July 15th, with fish agency support and a variance from the Comptroller of Water Rights, we moved the river flow down to 14 cubic metres per second for water conservation,” Watson said.
“This further lowering of the river on August 1st is part of this summer’s variance.”
Watson said BC Hydro continues to work closely with the Comox Valley Regional District (CVRD) on the Puntledge River system.
This lowering of the Puntledge River flow remains within the current CVRD Stage 2 threshold – there is no change to the CVRD watering restrictions.
BC Hydro will continue to keep the penstock full of water so the CVRD can draw water for domestic water use.
The Comox Lake reservoir level is currently at about 134.25 metres and continues trending downward at about three centimetres per day.
Watson notes that “135.33 metres is full, and the 131-metre level is where we get concerned about providing downstream river flows.”
The Comox Dam is about 300 metres from the outlet of the Comox Lake Reservoir. The current water inflow into the reservoir is about six cubic metres per second.
“We will continue to manage downstream flows as needed to manage the water storage through the summer and potentially early fall for fish habitat,” Watson said.