Local environmentalist concerned about water levels in river itself, not just the reservoir
By Lethbridge Herald on June 5, 2025.
Alexandra Noad
Lethbridge Herald
Local Journalism Initiative Reporter
Lori Goater peers out from her kitchen table to the dwindling Oldman River, which should be flowing with ample water, has slowly been getting smaller which can be easily noticed during times of drought such as the last couple of years.
Goater, who has a master’s degree in science with a focus on biology, has been concerned about the water levels for many years. She wants to send a warning of what is happening, especially during times of drought, and the impact the dam has on the river.
The Oldman River dam was completed in 1992 as a way to regulate the flow of the river to help make the water supply more reliable especially during the late summer and fall months.
When rivers naturally flow during the spring, they are higher, as the snow from the watershed melts and flows into the river. But as the summer months progress, the river dries up.
Natural rivers have a dynamic system that can easily adapt to changes, such as drought. Unfortunately, man-made systems, if not regulated properly, can disrupt a river’s natural flow and make it less adaptable for change.
The Oldman River also runs through Cottonwood Park. With cottonwood trees only lasting 60-100 years, the seedlings would disperse from the trees and into the river, and as the river levels would decrease, the seedlings would catch root on the banks, yet still be able to reach the water.
As the water levels have slowly declined, Goater has noticed there are very few new trees growing in Cottonwood Park.
When the Old Man River dam was created, many government scientists were on board with protecting the river, creating legislation such as the Water Act, Water Conservation Objective (WCO) which was arbitrarily set at the lowest amount of water needed to sustain the river. Below the range is called the Instream Objective, which is just deep enough to keep intake pipes submerged and have enough flow to prevent fish from stranding.
The WCO was meant to be updated after more information was gathered as to how to keep the river healthy, but unfortunately it wasn’t, says Goater.
This year in particular, the Oldman has been below the WCO since April and daily flows during May have barely met the Instream Objective, sometimes not even reaching it.
Goater is worried if the flow is too low for too long, it can cause issues with water quality and also cause with the structure of the river and riverbeds.
“If you keep the flow at this level for long periods of time, the river basically entrenches itself and it doesn’t support any oof the stuff that’s on the stream banks, so you don’t have as much resiliency.”
She adds that if the river entrenches itself, it won’t be able to have enough vegetation to trap sediment, which will then cause it to not be able to support spawning beds for fish. Then there is concern about sunlight reaching the bottom of the river, which will allow algae to grow.
Goater says that will affect how people use the river for recreation.
“You lose all sorts of other things, like you can’t boat in it, there’s fewer fish and they’re stressed out, so you shouldn’t be fishing them, even if they are there.”
Goater hopes to bring awareness to what is happening to educate about the fragile state the river is in due to overconsumption of water from the dam.
“Understanding that this is not a natural system, first of all, and that it’s fragile and we are in a particularly fragile state right now.”
19-18
perhaps some selenium will perk it all up?
Good article. We should all be concerned about the health of our river.
The city of Lethbridge has assumed responsibility for providing water not just to Lethbridge, but the other regional communities—Coaldale, Coalhurst, Monarch, Diamond City, Picture Butte, Iron Springs, Turin, and Shaughnessy—and it has had an effect on the river. Additionally, it supplies water to nearby companies like McCain and Agropur, so they and a few of the municipalities did not draw water from the river; however, the water is now redirected at Lethbridge, which lowers the flow.
You made a valid point about the riverbank trees! All of those trees thrived because the floods gave them moisture, but now that the yearly floods are not occurring during spring runoff, they are dying off and have not grown, as I mentioned a few years ago. The majority of those trees are disappearing!
In addition to controlling the river, the dam was necessary to supply irrigation for farmland, which is essential! We must strike a balance!
We need the river and we need food!
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