By Nikki Jamieson
Westwind Weekly News
Magrath residents were on alert for flooding at Pothole Creek last week.
On April 28, the Town of Magrath was alerted to the possibility of flooding, including an initial rush of water at Pothole Creek by Alberta Environment and Parks, due to construction taking place at Jensen Reservoir.
Communities downstream of the reservoir were alerted of the flooding risk after AEP discovered seepage coming from a newly constructed fuse plug emergency spillway on the Waterton-St. Mary Headworks main canal downstream of Jensen Reservoir.
A spokesperson said a third party engineering consultant was brought in and had assessed the situation as stable, and the site will be continuously monitored — as work is done to stop the seepage. The new spillway is part of a project to upgrade the flood handling capacity of the Jensen Reservoir and Dam to meet dam safety requirements, which includes upgrades to the already existing spillway and the construction of a second fuse plug emergency spillway.
The second spillway is considered to be a failsafe system, and would only be required during an extreme flow event to protect the main dam from failing.
The issue poses no threat to the main dam structure, and AEP will remain in close contact with the Town of Magrath and other communities downstream.
“The notice was sent out as a precautionary advisory to us as a down river stakeholder of the project, currently being done by AEP. Some seepage had been detected at their worksite and they were looking at immediate mitigation strategies,” said Magrath CAO James Suffredine, early Thursday afternoon.
“So far, releasing water into the creek has not been necessary. Currently, they are monitoring the location 24 hours a day and are working within their team for solutions. Overnight, the seepage did not get worse and after a further assessment today they reported to us there is only a low chance they will need to put water down the creek. They instead will continue to monitor the site — while engineering staff takes time to create a plan to resolve the issue.”
“The town is not directly involved in the project, so our recommendation based on the information received so far will continue to be that for the time being residents remain alert and keep outside the banks of the creek.”
An update on April 30 said the issue is considered stable and the risk of water release is low.
Direction will come from local emergency management departments if residents need to take precautions due to an increase in water levels.