Evaluating the Benefits & Risks of the Lake Diefenbaker Irrigation Project

Water - we can’t live without it and it is fundamental to so many activities - from agriculture to industry and from recreation to household use. Prairie dwellers, who have faced both drought and flood, are well aware of its importance. How we share and manage this resource is crucial to our survival.

The Lake Diefenbaker Irrigation Expansion Project hopes to provide water to over 500,000 acres of agricultural land in southern and central Saskatchewan. Proponents believe it will support the growth of high-value crops, increasing employment, investment, and value-added processing. The project’s website states that irrigation can help prevent drought, flooding and soil erosion, improve soil health, and increase food security.

It sounds fantastic, but will it play out that way in practice? The Citizens Environmental Alliance of Saskatchewan (CEA), along with other Saskatchewan environmental organizations, is calling on the federal government to carry out an environmental impact assessment on the proposed Lake Diefenbaker Irrigation Project. Jeff Olson, CEA’s managing director, explains why they believe an environmental impact assessment is important, listing 5 key areas that require greater examination.

Water Quantity

The South Saskatchewan River, which flows into Lake Diefenbaker, is fed by snow and glacier melt from the Alberta Rockies. Traditionally, glaciers melt faster in drought years and accumulate snow in cold years. This control feature will be lost as the climate warms and glaciers disappear. A recent research report shows that Alberta and BC glaciers have been melting 7 times faster over the past decade compared to previous years. John Pomeroy, Canada Research Chair in Water Resources and Climate Change, believes we must get climate change under control; otherwise “we're going to have to prioritize who gets water to drink, who gets water for growing food.”

The water in the South Saskatchewan River is shared by Alberta, Saskatchewan, and Manitoba. As with Saskatchewan, Alberta is undertaking major irrigation expansion projects and plans to use their full share - 50% of total flows - which could lead to reduced supply in Saskatchewan for not only agriculture but also industry (potash) and residential water in Moose Jaw, Regina, and Saskatoon. In a recent article, John Pomeroy is quoted as saying, “Approving expanded irrigation acres will only serve to intensify water use in basins that are over-allocated, rather than considering the needs for healthy aquatic ecosystems and the potential impact of the climate crisis on water availability.”

“If the Saskatchewan government has the data proving there will be enough water for the irrigation expansion, plus all the other uses, they have not shared that with the public,” Jeff Olson says, “For example, the water diverted for irrigation cannot be used for power generation, not only at Coteau Creek but also at the Nipawin and E.B. Campbell hydroelectric stations in Saskatchewan as well as hydro dams in Manitoba. For Saskatchewan this will mean loss of power production and therefore the need to obtain power from other sources, possibly including fossil fuel or nuclear, or the importing of electricity from other provinces or states. The proponent of the project has not presented this additional cost.”

Phase III of the irrigation project should benefit residential water users in Regina as it would ensure a more stable water supply from Lake Diefenbaker to Buffalo Pound. CEA questions why this phase is not being put ahead of Phases I and II but has not received an answer.

Modern irrigation normally decreases water demand. However, research has shown that it can have a rebound effect. A study of the Bow River Basin in Alberta notes that “many farmers who adopted modern irrigation systems and benefited from higher yields, reduced labour, and more precise application of fertilizer and chemicals, are using their surplus water allocations to expand operations and move to higher value crops,” thereby defeating the intended goal of water conservation.

According to CEA, evaporative water loss is still a concern if you take into account the network of reservoirs and ditches that will be built to deliver the water.

Because of the complexity and widespread impact of large-scale irrigation projects, John Pomeroy believes “the design should really be quarterbacked and spearheaded by a federal agency. It's not just a Saskatchewan project.”

Water Quality

The water currently entering Lake Diefenbaker is of very high quality. This will not be the case of run-off from fields following irrigation. Concern has already been expressed in many parts of the Qu’Appelle Valley about algae blooms developing on the lakes due to agricultural run-off.

Ecosystem

Of particular concern to environmentalists is the impact the irrigation project will have on the natural environment. “Agricultural land expansion will ultimately result in the ploughing of native prairie, drainage of wetlands, and destruction of aspen parkland as farmers attempt to irrigate all lands under the irrigation pivots,” Jeff says. “The total amount of acres of native lands to be destroyed has not been calculated and there is no Saskatchewan wetland policy or environmental assessment process to determine the extent of the impacts and the mitigation necessary to maintain a basic level of these ecosystems in the watershed.”

Saskatchewan River Delta

The Saskatchewan River Delta is North America’s largest inland river delta. It spans 2 provinces and consists of an intricate web of wetlands, shallow lakes, rivers, and forests. A rich, ecologically diverse area, it is home to hundreds of species of animals, plants, insects, and other living creatures. The 3 major dams upstream from the Delta have already had a significant impact by changing the amount and timing of water flow and movement of sediment. In addition, farms and cities release a wide variety of chemicals and nutrients that impact the water system further downstream. The Saskatchewan River Delta is already suffering. Jeff Olson says, “The irrigation project could be the final nail in the coffin.” His concerns are reiterated by Saskatchewan First Nations and CPAWS-SK.

Trade-Offs

It is clear that there will be benefits from the proposed irrigation project. It will protect downstream communities from flooding, ensure more stable municipal water supplies, and promote more angling opportunities. However, there will be trade-offs. The benefits and drawbacks must be clearly outlined and understood by the general public so that they can decide whether the benefits outweigh the risks.

The provincial government and the Saskatchewan Irrigation Projects Association have agreed that an environmental impact assessment may be needed at some point in the project, but there have been no commitments and no timeline established to ensure it occurs.

At this point, there are far too many unknowns. While much is known about the environmental impact of irrigation in general, no research has been done on the cumulative effects of all the irrigation projects in the South Saskatchewan River watershed or the environmental impact of the proposed mega-project. “Only through an environmental impact assessment will the impacts be researched, made public, and then accepted by the citizens as being acceptable trade-offs,” Jeff says.

The Citizens Environmental Alliance has a newsletter and posts regularly on Facebook. They are hosting the 3rd Annual Farmland Drainage and the Environment Conference, Feb. 28-Mar. 4.

Feb. 28, 10 am - A panel discussion on prairie wetland conservation policies

Feb. 28, 7 pm - Branimir: Gjetvaj: Why do we need more nature-friendly agriculture?

Mar. 1, 10 am - Landowner rights and responsibilities: laws, stewardship ethics, and conservation psychology

Mar. 2, 10 am - Dr. Masaki Hayashi: Understanding the role of topographic depressions in prairie groundwater recharge and the effects of land management practices on them

Mar. 3, 10 am - Does drainage pay?

Mar. 4, 10 am - An update on the status of farmland drainage, the environment, and wetland policies in Saskatchewan

Many past sessions have been recorded and are available on YouTube.