Sask. greenlights deal with Alberta, Manitoba to manage underground water reserves on Prairies

Saskatchewan's provincial government has greenlit expanding a key water deal to include cross-border groundwater reserves, aiming to ensure they are managed and shared sustainably amid growing threats posed by drought, pollution and climate change.

The proposed changes to the Master Agreement on Apportionment between Saskatchewan, Alberta, Manitoba and the federal government would empower the Prairie Provinces Water Board to assess, monitor and — if needed — take action to manage transboundary aquifers.

The Prairie Provinces Water Board, formed by the governments of the three Prairie provinces and the federal government in 1948, is responsible for the administration of the 1969 agreement, and provides a forum to resolve water issues between jurisdictions.

The changes to the agreement incorporate risk-management principles to the "collaborative" approach the provinces have taken to sharing surface water under the agreement since it was signed in 1969, according to the Saskatchewan Water Security Agency.

"WSA believes this amendment builds upon the strong, collaborative relationships of the PPWB members to continue to ensure Saskatchewan's water resources are sustainable, adaptable, and reliable," said Sean Osmar, the Saskatchewan agency's communications manager, in a statement emailed to CBC last week.

The change comes on the heels of plans in both Alberta and Saskatchewan to ramp up irrigation, as persistent drought damages crop yields and challenges the ability of farmers and ranchers to put food on their own tables.

Last month, Premier Scott Moe said Saskatchewan has begun design work and consultations as it's set to begin construction on the first phase of the Lake Diefenbaker expansion project next year.

Lake Diefenbaker was created in 1967 by the provincial and federal governments to supply water for a range of purposes, including irrigation.

Orders in council show that Saskatchewan Minister of Agriculture David Marit authorized the province's water agency to agree to the amendments to the interprovincial water agreement on March 28. 

The federal government has also agreed to the proposed expansion of the deal, according to an order in council.

The Saskatchewan Party government, like the governments of Alberta and Manitoba, supports including groundwater resources as part of the agreement, said a Thursday statement from Marit, who is also minister responsible for the water agency.

The amendment to the agreement is "a proactive approach taken by the board to include groundwater resources," Marit's statement said.

'Lesser-known' part of water systems

Aquifers are underground geologic formations made of layers of gravel, rocks and silt that can hold and store water that percolates down from rainfall and other sources on the surface. The water can then be accessed via a well, some of it already fit to drink.

These deposits vary in composition, thickness and depth but can span thousands of kilometres and cross one or more provincial boundaries, according to the proposed agreement.

Groundwater provides about one-quarter of residential water used in the Prairies and upwards of 90 per cent for residents in rural areas, plus "significant" portions of irrigation water for agriculture and livestock, according to a 2000 report from the Prairie Provinces Water Board.

The addition of transboundary aquifers to the agreement is a welcome one, says Patrick Cherneski, executive director of the PPWB.

Population growth and increased development is driving demand for well water both for drinking and irrigation, he said, but the water board doesn't currently have the power to help co-ordinate how the provinces should share or manage the supply.

"Groundwater is kind of the lesser-known, out-of-sight aspect of our water cycle," Cherneski said in an interview last week.

When people think of water, they generally think of surface water, but groundwater "is an important aspect because increasingly rural and urban residents are drawing upon it," he said.

Cherneski says that while the quality and supply of both groundwater and surface-level water in one jurisdiction can be influenced by activities in another, the stakes are often higher for groundwater management.

It's much harder to clean up an aquifer because they are isolated and their water much slower-moving than rivers and streams at surface level, he said.

"If there are any pollutants that get into an aquifer, first of all it's very difficult to get at, but it also takes a long time for that to move through the system," said Cherneski.

"It often can take decades or sometimes centuries for the water to flow."

He estimates there are as many as 30 major aquifers that his organization will identify and assess once the revised agreement enters into force.

Saskatchewan's water agency says provinces and the federal government are ready to move forward with implementation of the agreement once it is signed "to achieve sustainable and equitable sharing of water resources."

Cherneski says he expects it to be signed in the coming months.