The water levels are plummeting in the Cowichan River, and it means more than just bad news for people with inner tubes. The average rainfall in June and July was 85 per cent below normal, affecting not only recreational users, but the Crofton pulp mill and — most importantly — fish.
The crisis on the Cowichan River is a preview of the issues we face on the Island and in the province as the climate changes. Melting glaciers, lower rains, hotter summers are a reality.
On Saturday, Island Health warned people to stay out of the lower reaches of the Cowichan, particularly downstream of the Trans-Canada Highway bridge in Duncan. Tests of the water after last week’s rain showed unusually high levels of bacteria, which exceeded federal guidelines for recreational water quality.
The coliform counts were more than three times higher than acceptable levels. The problem was caused not by treated sewage effluent, which flows into the river, but by bacteria washed from the land and storm sewers by last week’s rain. In fact, the water quality was better downstream from the effluent outfalls than upstream, according to Island Health.
By Wednesday, tests confirmed the water was back to normal, and the warning was lifted.
The material flushed from the land, particularly agricultural land, becomes more concentrated when the water level is so low.
The level is falling because there is less water in Cowichan Lake. The snow pack is smaller than in the past, and the area had less rain than usual in the spring.
The Crofton pulp mill takes 120 million cubic metres a year, using an intake about nine kilometres from the mouth of the river. Water storage in Cowichan Lake is controlled by a weir, built decades ago as part of the mill’s water licence, and the mill is required to allow enough water over the weir to feed the river. That has become a problem.
The flow is supposed to be at least 7.08 cubic metres a second, but the mill got the OK to cut it to five and then to 4.5. The drop-dead flow is four cubic metres — at that point, the mill would not have enough water and would have to stop operating.
While that might seem like a local concern, the pulp mill means more than 600 jobs in the Cowichan Valley and puts $1 billion a year into B.C.’s economy.
For fish, the reduced water levels can be devastating. At 4.5 cubic metres per second, the river flow is 95 per cent lower than in mid-winter. Low water means higher temperatures, which can be deadly for fish. Volunteers are helping stranded fish; there is talk of pumping water out of the lake to raise the river level and raising the height of the weir.
But those solutions won’t fix the long-term problem.
What is happening in the Cowichan River is not necessarily a direct result of climate change, but it’s the kind of problem we will face more and more often in coming years as snow packs continue to shrink.
If we want to preserve rivers and lakes for fish, recreation and industry we need a real, long-term mitigation plan. We cannot treat low water levels as transient annoyances; they are a fact of life.
The choices won’t be easy. Raising the weir at Cowichan, for example, would solve some of the problems but flood out cottage owners.
Efforts to slow climate change represent one priority, but we need an equal focus on mitigation measures of all kinds, from river management to considering how we will deal with rising ocean levels.
