Smarter nutrient use in everyones’ best interest

MOOSE JAW, Sask. — Pristine water from the Rocky Mountains is loaded with nutrients by the time it reaches Saskatchewan’s Lake Dief-enbaker, says a water expert.

Howard Wheater, director of the Global Institute for Water Security at the University of Saskatchewan, said researchers are keeping an eye on water coming from the mountains through Alberta’s river systems and into the lake.

Nitrogen and phosphorous are entering the lake, but phosphorous is by far the most concerning to scientists. It can lead to significant algal blooms that cause water quality issues and problems for water treatment systems.

Wheater said the phosphorous is settling into the lake sediment and remaining unavailable.

“Over the last couple of years, what we’ve seen is about 86 percent of phosphorous that’s coming into the lake is staying in the lake,” he said in an interview during the Saskatchewan Irrigation Projects Association conference.

“It’s a sink.”

Wheater said sunlight is critical to making phosphorous bioavailable. The big loads of nutrients that are coming down the rivers have been accompanied by a lot of turbulence and sediments, which have restricted the light and kept algal activity minimized.

That said, the Qu’Appelle arm of the lake, which feeds Buffalo Pound Lake, does experience algal blooms. Last summer, Regina and Moose Jaw were under water restrictions because the treatment plant couldn’t handle the algae.

“The concerns for the future really are if we would get increasing temperature with a warmer climate, and perhaps reducing flows and having clearer water, then that might well lead to mobilization and algal blooms,” he said.

“So we should be aiming to do our best to reduce the input of nutrients to the system.”

Wheater said research clearly shows the nutrient loading is occurring in Alberta. He said cities have invested heavily in advanced water treatment systems, so even though populations are increasing, the nutrient load should be de-creasing.

This is more difficult in smaller communities that can’t invest in new technologies.

Agriculture is contributing to the problem, and Wheater said watershed associations are doing good work with producers to educate them and help find resources.

Creating buffer strips, retaining wetlands and other beneficial management practices help.

“Some of them, of course, are in the farmers’ financial interest and some are not,” Wheater said.

“We really have to work to be more smart in the way in which we manage the environment and be more efficient about the way in which we use nutrients in agriculture, and then it’s a win-win for everybody.”

He said nutrient loading of water bodies is a global problem that crosses many boundaries and involves many players.

The water institute’s South Sask-atchewan River Basin Project is one of 10 Global Energy and Water Exchanges initiatives and the only one in North America. It is looking at water management, quality, quantity, social issues, policy and economy.

Wheater said the 336,000 sq. kilometre basin is a huge observatory that is part of a world climate research program. It includes observation sites in the Rockies, on Peyto Glacier, through the boreal forest and across the Prairies.

For example, a site at Kenaston, Sask., was originally established to look at soil moisture from space but is now used to study the interaction between the land and the atmosphere, he said. Tobacco Creek in Manitoba is a site for agricultural nutrient loading research.

A recent issue of the Journal of Great Lakes Research focuses on the project.

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