Dry conditions prompt N.W.T. power corp. to seek change to water licence

Dry conditions and low water levels are affecting hydro generation in the N.W.T. this year, prompting the territory's power corporation to ask to draw more water from a hydro reservoir than is normally allowed to under its current water licence.

The Northwest Territories Power Corporation (NTPC) has applied to lower the minimum level at which it can draw water from the Big Spruce reservoir to feed into the Snare Hydro system, which provides power to Yellowknife, Dettah and Behchokǫ̀. 

Because of the low water levels, there's not enough water to power the Snare Hydro system, a series of four hydro plants that provide power to North Slave communities. 

While the Snare Hydro system usually provides around 98 per cent of all the electricity to Yellowknife, Dettah and Behchokǫ̀, this fall it's been providing 55 per cent. The remainder has come from burning diesel at the Jackfish power plant — which is more costly and worse for the environment

The corporation has used millions of litres of diesel to offset this lack of hydro generation.

Lowering the minimum water level at which it can draw from the Big Spruce reservoir means the power corporation can continue with "planned hydro generation and avoid some diesel generation," according to the NTPC.

The NTPC has applied to the Wek' èezhı̀i Land and Water Board to change its current licence. The board has granted temporary approval in the past when water levels have been low, including this year when NTPC was allowed a 30-centimetre water-level reduction for the Big Spruce reservoir. 

'Not as reliable as they were'

Dennis Bevington, a renewable energy advocate in the territory, said that climate change has had an impact on the viability of hydro generators for the North Slave Region. 

"It certainly means that they are not as reliable as they were in the past," he said. "That's very clearly the case. Last 10 years we've had two events where we're forced onto diesel in the Snare Hydro system." 

Bevington said that while he generally supports the use of hydro as a source of renewable energy, it is showing vulnerabilities as well. He cites extreme weather events that result in too much water, or too little.  

"As the Earth heats up, the likelihood of larger weather events being either droughts or rain events is more likely to happen — and that's exactly what we're seeing," he said. 

"Those things are, I think, a fairly good indicator that climate change is working on the [Snare Hydro] system."  

This year, Yellowknife saw its sixth-driest and second-warmest fall on record. 

"The weather throughout the fall, it's been very, very warm and very, very dry compared to what normals would be," said Alysa Pederson, a meteorologist with Environment and Climate Change Canada. 

Pederson said one of the reasons the N.W.T. is experiencing a drought is because there is a big dome of warmer air that sits over B.C., Alberta, and the Northwest Territories. The dome of air blocks storms from coming to certain areas so most of the precipitation has gone further north than the southern part of the N.W.T. 

The meteorologist also expects this winter to be warmer and drier than normal.