Is Lake Diefenbaker's irrigation megaproject still environmentally viable?
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"We’re on our way to being Alberta, only a little faster," said Saskatoon farmer and environmental watchdog Murray Hidlebaugh.
Larissa Kurz - Published Mar 30, 2024 • Last updated Apr 03, 2024
Several Saskatchewan environmental groups say concerns about blind spots in the $4-billion Lake Diefenbaker Irrigation Project have not gone away while the project has been on the shelf.
Earlier this month, Premier Scott Moe made a public recommitment to begin Phase 1 of the megaproject, first unveiled in 2020 and dubbed the largest infrastructure project in the province’s history.
The project had stalled as the province waited for a firm answer on federal investment. Construction is now promised to begin on the first phase by 2025 at an inflated $1.15-billion cost, regardless of Ottawa’s involvement.
Murray Hidlebaugh, volunteer water advisor with the Saskatchewan Environmental Society (SES) and a tree farmer near Saskatoon, says few questions have been answered in the limbo since 2020.
Primary among them is Lake Diefenbaker’s capacity to handle an increased draw on its stores for agricultural use as several years of drought conditions pinch water supply across the Prairies.
Diefenbaker is carefully monitored by the Saskatchewan Water Security Agency (WSA), a fact often pointed to by supporters of the project as proof that any risks are being well-considered.
But Hidlebaugh and Nature Saskatchewan president Jordan Ignatiuk questioned the wisdom of risking overdraw from Diefenbaker, which is the source of 60 per cent of Saskatchewan’s drinking water and a hub for industry, recreation and wildlife.
“The last two or three years definitely should be some warning signs that things are changing, and they’re not changing for the better,” Ignatiuk said in an interview this week.
“What is the reliability of the reservoir, despite its size?”
SES and Nature Saskatchewan say they want clearer answers on how adding more irrigation will impact water security, water quality and the entire ecological integrity of the Saskatchewan River Basin.
Concerns about dwindling natural inflows, potential loss of native prairie grasslands being converted to cropland and degradation of wetlands should be reason to pause, the two organizations say.
“We’re not anti-irrigation,” Hidlebaugh clarified, but rather pro- “environmental resilience” and protection of Saskatchewan’s resources.
A dream on the shelf, renewed
The Lake Diefenbaker Irrigation Project isn’t a brand new idea, but rather a modern reimagining of a plan originally made in the 1930s and launched in the 1960s when former prime minister John Diefenbaker ordered the construction of the man-made reservoir.
The two bookends to the lake that shares his name — Gardiner Dam and Qu’Appelle River Dam — have been called “the dams the drought built.”
Always in the vision was an irrigation canal network stemming from the dams, coined in the years since as “Saskatchewan’s unfulfilled dream.”
The Saskatchewan Party’s revived vision seeks to finish what was started nearly 55 years ago by more than doubling the acres of irrigated land in South Saskatchewan in three phases over 10 years.
Phase 1 and 2, the Westside Irrigation projects, are meant to rehabilitate existing canals, then expand capacity as far north as Asquith and Delisle. Phase 3, the Qu’Appelle South Project, will stretch to connect to Buffalo Pound Lake and supply the Moose Jaw-Regina corridor.
All in, nearly 500,000 acres will come online once all three phases are complete — about one per cent of all cropland in Saskatchewan.
Phase 1 is estimated to cost $1.15 billion, previously a $500-million target. Plans are to add 90,000 acres at a cost of $12,000 per acre under the currently OK’d cost-share model.
Ralph Goodale, a former federal Liberal MP and political champion of this proposal for many years, said that hearing movement on the project is exciting and he still stands behind this expansion as a boon for the agricultural sector.
“The dream, if you will, is even more relevant than it used to be,” he said in an interview this week.
“The challenge that we’re facing now, going into the future with the impacts of climate change, is potentially even larger than the circumstances we faced in the 1930s.”
For his part, Ignatiuk rejected the suggestion that irrigation is a countermeasure of climate change.
“It’s going to actually exacerbate it, as opposed to being any kind of benefit,” he said.
Will Lake Diefenbaker have enough water?
Benefits are well-documented in political talking points, which tout boosts to crop diversification, public sector investment and yield stability in the face of drought conditions.
Enthusiasm from agricultural stakeholders was also vocalized in 2020, including the Saskatchewan Stock Growers Association, various affected irrigation districts, watershed associations and water basin boards.
Goodale described the project’s philosophy as “building surge capacity” to weather natural “feast or famine” water cycles, rather than a continual drain on water sources.
“If you have the built infrastructure to be able to collect and control, … then you can spread out the boom and the bust,” he said.
Several organizations disagree and have made loud calls for an environmental impact study to answer questions before shovels hit the ground next year.
Ignatiuk said red flags were raised four years ago and concerns have only increased as water levels at Lake Diefenbaker continue to drop in recent years.
Estimates indicate the Westside expansion will pull 600,000 cubic decametres annually. Once Qu’Appelle South is also online, draw will total 860,000 cubic decametres.
Current data from WSA shows the South Saskatchewan River was at just 10 per cent of normal flow levels last year, delivering just 28 per cent of average inflow to Lake Diefenbaker from the west.
Water levels dropped by about two metres as a result, and flow restrictions were put in place midsummer. Lake volumes in 2022 were similarly down, at the second lowest in the last 30 years, attributed to extended dry conditions in southern Alberta.
Drought risks are expected to persevere across Alberta and Saskatchewan in 2024, according to the Canada Drought Monitor’s most recent report. It predicts minimal spring runoff once again, plus mitigated winter precipitation gains due to exposed soil in the south and west suffering evaporation and freeze drying.
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Hidlebaugh and Ignatiuk both questioned if investing in more irrigation pumping from the reservoir should even be on the table under such conditions.
“It’s a risky proposition, at this stage,” said Ignatiuk. “Water is life and it comes down to the importance of that.”
Low water volumes in Lake Diefenbaker have the potential to impact watershed health and Saskatchewan’s ability to fulfil water-sharing commitments for industry, local municipalities and downstream to Manitoba.
The communities of Cumberland House Cree Nation and Leader each declared a state of emergency last year due to dwindling reservoirs fed by the South Saskatchewan River, which is now at its second-lowest level since 2001.
Reduced flow through Lake Diefenbaker could impact fisheries and power generation at any of the 10 hydroelectric stations downstream. SaskPower figures from 2012 suggest a loss of $1 million to $2 million of sellable power per metre of water drop.
Wetlands in the newly irrigated regions may be the most affected, said Ignatiuk. More irrigation could mean higher levels of pesticides and salts in surface run-off, potentially degrading nutrient stores, heat sink capacity and precipitation in the summer.
“If we dry (our wetlands) out like we did back in the ’30s, to where it can’t rain, (then) it’s just too hot,” Hidlebaugh said.
John Pomeroy, director of the Global Water Futures program at the University of Saskatchewan’s Global Institute of Water Security (GIWS), said anxieties about the expansion’s size are understandable, but not unsurmountable.
There will be an increased draw on the lake, “there’s no doubt about that,” he said, “but those withdrawals can be managed.”
Doing the math on the fly, Pomeroy said in a low-flow year like 2001 — the one year with lower levels than 2022 — the Westside Pump Station would consume between 20 and 22 per cent of water coming into Lake Diefenbaker. Adding in Qu’Appelle South boosts that number to about 33 per cent.
Pomeroy said consumption in wet years would be closer to three per cent, which is on par with how much water evaporates off the lake each year.
“Twenty per cent is manageable,” he concluded. “It’s encouraging that the system can undertake tremendous stress such as in 2023 and still carry on.”
The WSA said a review of 88 years of flow data found average water availability offers a 200,000-acre-foot buffer between available volume and the entire project’s estimated need.
Natural flows from Alberta have changed significantly since the 1970s, dropping as much as 12 per cent on the South Saskatchewan River and 40 per cent overall as more irrigation and reservoirs were brought online.
It has meant restricting outflows at times, including last year when lake levels dipped enough to decrease electricity generation at Gardiner Dam. Pomeroy called it a “balancing act” to keep the lake in tune.
“Water is always a limited resource in the prairies,” Pomeroy said. “In the driest years, as with any reservoir, water management decisions would be made as to how to allocate water to ensure that all the crucial uses are covered in some way.”
Off the cuff, Pomeroy suggested releasing less extra water downstream or having restrictions on irrigation use in severe dry conditions.
Hydrological modelling predicts stream flow in the South Saskatchewan River will increase 20 to 40 per cent due to coming rainfall in the Rockies, he continued.
“There are ways to manage this and it still would provide a tremendous benefit to the irrigated lands, compared to the dryland farmers around there,” he said.
For environment watchers like Hidlebaugh and Ignatiuk, the outlook feels less rosy.
Hidlebaugh pointed to Alberta, where 2024 predictions already have the provincial government re-evaluating local water-sharing agreements to pre-empt allocation pressures for the first time since 2001.
He also noted that even an additional three-per-cent draw is compounding on top of what’s already being pulled for the East Side Pump Station, doubling the depletion.
“I don’t think the system will work, the way it is,” he said. “We’re on our way to being Alberta, only a little faster.”
Pomeroy said the health of Lake Diefenbaker will rely on “good choices,” efficiency and “careful stewardship” as this project progresses.
“This is one of the newest irrigation expansions in the world and it is a great chance for us to get it right and to do a better job here than anywhere else,” he said.
Added Goodale: “For this project to succeed, people (need to) feel involved and engaged and consulted, and that they are a part of, not left out of, the ultimate dream.”
Federation of Sovereign Indigenous Nations Chief Bobby Cameron said in a prepared statement that he is still “deeply troubled by the absence of meaningful consultation with First Nations.”
“The current state of water in Saskatchewan is dire,” he said in a recent news release which was similar to one sent by the organization in 2020. “Responsible use of our collective water resources is paramount.”
The WSA said more engagement will take place over the next 12 to 14 months, including with treaty rights holders.
Engineering, design and permitting processes yet to come will look at water modelling, geotechnical and hydrological concerns and the viability of the irrigation concept.