The scientist sounds the water crisis alarm

The drought affecting the western United States has led a scientist to warn that the prairie provinces of Canada need to better plan how water is used throughout Saskatchewan’s river system.

“A California water expert we had here a few years ago said that Alberta and Saskatchewan reminded him of California and Arizona around 1912,” said John Pomeroy, Canada’s Chair in Water Resources and Climate Change Research. of the University of Saskatchewan.

“We’re still having a good time, we have pretty loose deals, everyone is doing well, it’s fine, but we have problems ahead.”

The Saskatchewan River System includes the North and South Saskatchewan Rivers, along with major tributaries such as the Bow and Oldman Rivers in Alberta. Its headwaters are on the eastern slopes of the Rocky Mountains, providing water that farmers and communities in Alberta and Saskatchewan rely on.

About 80 percent of the flow in the Saskatchewan River Basin comes from the eastern slopes, and the main engine is the snow cover, making it “very vulnerable to climate change,” Pomeroy said.

I used to think that the impact on the system would be decades in the future, “but after this summer’s drought … I think it will be very fast. We are already here. “

Record heat waves affected farmers and ranchers in much of western Canada last year. Pomeroy said groundwater supplies dried up during the summer and fall, bringing November levels in the Bow River back to normal.

The Oldman River also dropped to less than half the usual flow during the summer, and some small tributaries of the mountains dried up. A high layer of snow will be needed during the winter for the two rivers to generate enough flow to replenish irrigation and hydroelectric reservoirs, Pomeroy said.

Although recent rainfall has increased the snow cover that feeds the Bow River to twice what is normal for this time of year, it will not be known until March or April if the accumulated levels are high enough. , he said.

Meanwhile, the December 8 snowpack had not accumulated in the Oldman River watershed “at all, and that’s why they have to keep an eye on it.” However, the rapid change in BC from summer drought to floods in November shows how quickly circumstances can change, he added.

Despite these considerations, Pomeroy said there is a link between the record-breaking hot weather that hit western Canada in 2021 and the ongoing drought that has dominated the western United States.

“And that’s more than a decade ago. At the time, they called it a mega-drought, but (in 2021), that mega-drought accelerated from southern Mexico to western Canada to the southern Yukon, and then due east to Quebec and New Brunswick. “

He noted the Colorado River system, which supplies water to about 40 million people in seven states, including Arizona, California, Colorado and Nevada. Users range from farmers to cities like Las Vegas and Los Angeles.

Pomeroy said that the prairie provinces of Canada “could easily face the problems that Americans have in the Colorado River right now where they over-allocated water years ago … and now they have greatly reduced the mantle of “Snow in the mountains, and the reservoirs are falling and not filling up. Every year properly.”

The crisis is forcing the United States to close the irrigated districts on which farmers depend because there is not enough water to circulate, he said.

“We don’t want to get into this situation.”

The snow pack on the eastern slopes of Alberta could melt up to two months earlier than it is now, he said. It is now melting in mid-June, in time to cover the maximum downstream irrigation needs.

“But if we end up with a maximum flow in April, then the lack of timing of flows and use will be something we will have to manage very carefully. Irrigators may need to increase their water storage capacity downstream. “

Canada needs to improve its forecasting models to provide weekly forecasts and to create seasonal forecasts looking at three or even six months, Pomeroy said.

“Many of the models have been developed at the research level in universities, but are not yet operational.”

Although scientists have conducted tests at smaller scales, supercomputers and dedicated federal-provincial cooperation are likely to be needed to operate on a continental scale, he said.

This information could help officials better decide whether to keep reservoirs full to withstand an expected drought or reduce them in preparation for flooding. It could also help farmers plan crop selection in the middle of winter, he added.

Another problem is that the Prairie Provinces Water Board has an agreement that only looks “very loose.” The board includes the federal government, as well as Alberta, Saskatchewan and Manitoba.

Water use is not really considered in terms of the impact on the entire system under climate change, Pomeroy said. Over the past two years, Alberta has launched a nearly $ 1 billion expansion of its irrigation system, which is one of the largest of its kind in the province’s history.

The Alberta Wilderness Association said on November 15 that “this large expansion of reservoirs, pipelines and irrigated land (in the province) … has largely been presented as a preliminary conclusion. It has not been submitted to no public consultation and no environmental impact assessment of the project has been carried out “.

Irrigated agriculture already accounts for 78 percent of water allocations in the Bow and Oldman river basins, the association said.

“The approval of the extension of irrigated hectares will only serve to intensify the use of water in the basins that are over-allocated, instead of considering the needs of healthy aquatic ecosystems and the potential impact of the climate crisis. on water availability “.

However, the Alberta government has said the expansion will increase irrigated area and primary crop production while improving water use efficiency through the use of pipes instead of canals. of open water.

The targets will be met within existing water license allocations, said Provincial Minister of Agriculture, Forestry and Rural Development Nate Horner on November 12th. “I look forward to seeing more projects start over the next few years.”

Meanwhile, Saskatchewan began a 10-year, $ 4 billion project on Lake Diefenbaker in 2020 that will double the amount of irrigated land in the province.

Pomeroy said he hadn’t looked into expanding Alberta’s expansion, “but Saskatchewan is expanding as well, and it really means we need a detailed study of the entire Saskatchewan River Basin … to make sure that there is enough water for everyone because that water is going to Saskatchewan. “

The basin supplies about 70 percent of Saskatchewan’s population and its entire irrigation system, along with hydroelectricity, he said. It also supplies the Saskatchewan River Delta to Cumberland House.

As it is the largest inland freshwater delta in North America, the area “already suffers from low flows and ecological devastation, a very difficult situation for the natives there,” Pomeroy said.

These consequences make it “important to look at everything before extending irrigation in one part or managing it differently in another part, and we must always do so by looking at the mountain.”

Irrigated agriculture accounts for 78 percent of water allocation in Alberta’s Bow and Oldman River Basins. | Archive photo

The Alberta government has called for public input on possible open-pit coal mining on the eastern slopes to help create a new coal policy for the province.

Additional mining will increase pressure on water use in the Saskatchewan River system and studies on the impact on water quality of existing open pit coal mines in BC have detected toxic amounts of selenium in the runoff of this province, Pomeroy said.

Researchers have found levels above “that you could use to irrigate crops or give to livestock or humans.” This pollution is “very difficult to clean up. The impacts last for hundreds if not thousands of years.”

In a previous interview, Alberta Wilderness Association Executive Director Ian Urquhart called for a comprehensive plan to include all uses on the eastern slopes, including forestry.

The need for integrated planning for the entire Saskatchewan River system is especially important because Canada’s food demand has continued to grow, Pomeroy said.

There is a danger that the cities of the Prades could dominate the rural areas in terms of water use, he said.

“What became clear in the United States and Colorado is that when it comes to fighting for water between cities and rural areas, cities win … and so putting those protections in place would soon be beneficial. “.

from
https://vegetablesnow.com/the-scientist-sounds-the-water-crisis-alarm/