It could be a slower than normal tube float down the Red Deer River this summer, but that’s to make sure tap water flows as usual next winter.
The bare minimum amount of water is flowing into the Red Deer River now downstream of Dickson Dam, as operators work to fill Gleniffer Reservoir by fall.
Alberta Environment’s water supply outlook forecast for the Red Deer River basin is much below average for the June to September period. A much below average to below average snowpack, and the dry spring have had an impact on the Red Deer River.
Rick Friedl, with Alberta Environment and Parks, said Gleniffer Reservoir is being filled and the flow out of the dam into the Red Deer River is being held at 16 cubic metres per second, the lowest permitted. At the same time, the flow into the reservoir is 37 cubic metres per second. The difference between the two volumes is filling up the reservoir.
The reservoir is drawn down during the winter months to maintain adequate river flow downstream to assure the water supply to Red Deer, Medicine Hat and other communities. The dam is also used to lessen seasonal flooding when there is too much water.
“We’re trying to capture a little bit more water and fill a little bit quicker because we’re seeing the rivers a little bit lower,” Friedl said.
The water supply outlook for the Red Deer River Basin as of June 1, based on natural flow, shows a volume forecast of 69 per cent of average between June 1 and Sept. 30, at Dickson Dam, and 61 per cent at Red Deer.
Forecasts are just that, and can change depending on precipitation and temperatures.
Last year, the actual recorded March to September volume was 137 per cent of the average. The average is calculated with volumes from March 1 to Sept. 30 between 1981 to 2009.
Friedl, who is director of the operations infrastructure branch for the North Central Region, and based in Red Deer, said the water level at Dickson Dam at capacity is 948 metres. The goal is to get Gleniffer Reservoir at 946 metres. On Wednesday morning, it was at 945.42 metres, or 80 per cent of total capacity. Tuesday it was at 79 per cent.
“Every summer we’ll hold it at two metres below full as we get through July, because that’s the ideal recreational level, and then based on what the water inflows are doing and what the water supply outlook looks like at the time, we’ll start to fill the reservoir up so that it’s full coming to middle to end of August.
“As we get into September, we’ll hold the reservoir as full as we can, and in the winter we’ll start dropping because we’re adding water to the flows in the winter,” said Friedl.
The filling of the reservoir is going well despite there being lower than normal inflow into the reservoir, he said.
“We’re trying to capture a little bit more water and fill a little bit quicker because we’re seeing the river a little bit lower.”
If the inflows were to stay where they are today for the rest of the summer, they would have no problem filling Gleniffer Reservoir, he said.
“If it gets really, really hot, we need to be sensitive to fisheries and things like that, and the water temperature, and we’ll make those decisions as they come up, if they come up, when we start getting into July and August.”
So far, Friedl said they have not received any concerns about the low river flow.
They could need to supplement the flows downstream of Dickson Dam but it’s impossible to know right now, he said. They’ll know better in a month.
The Red Deer River downstream could end up at the minimum 16 cubic metres per second through the summer, depending on precipitation and temperature, Friedl said.
“When it gets hot, we need to see normal precipitation and we’ll be in fine shape, but if it stays hot and dry then we’ll have to see what happens. ... That’s the crystal ball thing.”
The weather forecast trend shows temperatures over the next week or so ranging between 25C to 31C, with possible thunderstorms but no general sustained rainfall.
barr@www.reddeeradvocate.com