Sask.'s $4B irrigation plan must address changing climate, Indigenous rights: professor

The Saskatchewan government has announced a $4-billion plan to expand irrigation out of the Lake Diefenbaker reservoir. Work is set to begin immediately, and will be completed in three phases over the next decade.

CBC reporter Jason Warick spoke Friday with John Pomeroy, a Canada Research chair and director of the University of Saskatchewan's Global Water Futures program. 

The following interview has been edited for length and clarity.

What do you think of the government's announcement?
The announcement was not a surprise. This has been in the works for some time. But certainly the scope of it is truly remarkable, an incredible event in many ways for water resource management in Saskatchewan.

The expansion of irrigation is something that was long planned for Lake Diefenbaker. The original expansion of the project was largely not realized. The reservoir was designed to do this. That's what it was built for.

What are some of the issues that need to be considered?
It's 2020. We have downstream users. We have rapid climate change occurring, and we have unresolved downstream issues for Indigenous communities. So lots of things need to be sorted out beyond the irrigation expansion itself.

Does it seem like a good idea overall?
As a scientist, I won't say something's a good idea or not a good idea. There's a will to do it, so I think what's important is that it has a scientific basis to its design, that it's designed for the 21st century, not the 20th. There are trans-boundary and Indigenous issues involved — this water flows into Manitoba. There are lots of other considerations.

Like what?
One example is if we take water out of Lake Diefenbaker and use it for irrigation, it will mostly evaporate through the growth of crops. That means it won't be able to run [at the same levels] through the turbines to generate hydro electricity at Gardiner Dam. Nor will that stream flow be available to Manitoba to generate electricity.

Can you talk about any possible effect on ecosystems?
That flow also won't be available for the necessary sediment load and flooding of the Saskatchewan Delta near Cumberland House, which is crucial for that ecosystem and for the lives of Indigenous communities in that area.

Are the proposed volumes to be diverted for irrigation sustainable?
In the last 20 years, we've had some very low flows in the river that would challenge a large irrigation project. But [it can work] as long as you manage it properly and understand that there are years where we have to hold water back.

But we also have to take into account the changes that are occurring in a shifting climate. Saskatchewan in 50 years, 100 years — the life of this project — will be much warmer and somewhat wetter, but much more variable; some flooding, and droughts in between. It could be very useful to have [this project] to manage that.

The estimated cost is $4 billion. It will irrigate hundreds of thousands of acres. How significant is it?
It's a massive project. It would dramatically expand irrigation from what it is right now.

Do you have any other thoughts?
Because the Saskatchewan River basin flows from Alberta to Saskatchewan and Manitoba, with Indigenous communities as well, this is certainly a national project. The complexity is immense. The design should really be quarterbacked and spearheaded by a federal agency. It's not just a Saskatchewan project.