BC River Forecast Centre says conditions here are dry, and local streams flows are hitting record lows.
Editors note: The BC River Forescast Centre upgraded drought conditions from normal to dry just after the print version of this article was published on Monday. The online version has been edited to reflect this change.
It’s hard to worry about water in Revelstoke. We’re in a rainforest, and the Columbia River and it’s many tributaries gather the snow melt and the rain and send a seemingly endless flow of water past our banks.
Still, it’s hard to avoid the news that drought conditions are increasing in the rest of the province. As of July 27, the BC River Forecast Centre rated conditions as extremely dry in most of southern B.C. The Kootenays and Columbia regions were rated as dry, while the Okanagan was considered very dry.
The forecast centre uses a four level drought scale that ranges from normal to extremely dry.
In Vancouver, the drought has resulted in the regional government imposing stage three water restrictions for the first time since 2003, meaning residents can no longer water their lawns. Vancouver’s reservoirs are at 69 per cent of capacity and officials hope the restrictions will allow them to stay there until the usual fall rains arrive.
Fishing has been banned on some rivers in order to protect the fishery.
By now, we know what’s happened to the weather. Precipitation was around historic normals for the first half of the winter, but warmer temperatures resulted in an early freshet, meaning local streams reached peak flow earlier than usual. Then, we entered a prolonged hot and dry spell, accelerating the melt. In Revelstoke, rainfall was less than half historic norms in May and June, and July has been drier than usual too.
The Revelstoke are was rated as a one on the River Forecast Centre’s drought scale until Monday, when the centre issues a new advisory that jumped the rating to two on the four-level drought scale. Environment Canada streamflow data reflects those conditions, with local creek flows hitting 50-year lows.
Two rivers are measured in the Revelstoke area – the Illecillewaet near Greeley Creek, and the Goldstream near the Columbia River – and they both dropped below the previous recorded lows last week. Records go back to the early 60s.
Wenda Mason, a manager at the B.C. River Forecast Centre, said much of the province is in the grip of low winter snowpacks combined with a drought and early and continuing high temperatures.
“It’s more typical of late August than mid-July,” she said.
All that said, there’s only one creek that matters to Revelstokians when it comes to our day-to-day lives, and that’s Greeley Creek, where the city gets most of its water from. Even it appears to be drier than usual, though the data is quite limited because the city only monitored the creek’s discharge regularly in 2007 and 2008, and infrequently in 2009 and 2012.
To see what’s happening, the city has gone back and measured the creek flow twice this month. The measurements are taken below the city’s water intake, meaning they show what’s left in the creek after the city takes it’s share.
The first reading was taken July 8; it showed a flow of 2,257 litres per second. At around the same time in 2007, the flow was between 6,000 and 7,500 litres per second. In 2008, it was about 5,000 litres per second.
The city took another reading last Thursday, July 23. I watched as the city’s technician Derek Low took the measurements. He recorded a flow of only 1,500 litres per second. Mike Thomas, the city’s director of engineering told me the creek doesn’t reach those that level until well into August.
“We’re probably five weeks ahead in terms of that stream flow,” he said.
The flow is also above annual lows, which, based on the minimal available data, appear to bottom out between 200 to 300 litres per second in February.
The good news is that the city only takes a fraction of the creek’s water. On July 22, the city withdrew 127 litres per second from the creek, but Thomas said that was a particularly high day where the city was refilling the Trans-Canada Reservoir. Normally, it takes out about 80 per cent of that amount.
Right now the city is on stage one restrictions, meaning water can only be used for sprinkling or irrigation from 6–10 a.m. The city runs its well at the golf course to help meet the morning demand.
Even with Greeley Creek providing more than enough water for the city’s need, there is the possibility the province could impose restrictions if it deemed the area was entering into a drought.
“If they go to a drought level three or four, there may be stream withdrawal reductions,” said Thomas. “That may prompt the city to have to implement a higher-level of water restriction.”
One thing Thomas would like to do is prepare a drought plan that would set out triggers for when the city imposes water restrictions. He’s budgeted $60,000 in 2016 for a water supply review.
“What would our contingency be? What would our response be? What’s the golf course well capable of producing?,” he said. “Try to come up with a solution that provides that drought level water supply for the community.”
Revelstoke’s water supply appears to be secure. The Greely watershed drains a large area to the north and east of Mount Mackenzie and Ghost Peak. The big snowpack essentially serves as a reservoir for the city, providing an abundant supply of fresh water year-round.
Thomas said he’s not concerned about the city’s water supply, but he still wants to see how fast it’s declining this summer, which is why the city has resumed measuring creek flow.
“Is it on a rapid downward trend or is it on a gradual downward trend?” he said. “We’re still many factors of safety off anything I’d be worried about. But how’s that going to change over the rest of the summer?”
With files from Kamloops This Week
