EXSHAW – The MD of Bighorn is another step closer to understanding groundwater flooding in Exshaw.
The municipal council unanimously approved a request for proposals be sent out to have an engineering firm better understand the causes of high groundwater flooding as well as the influence storms, snowpacks, creeks and the Bow River have on the area.
However, following previous concerns over prior engineering studies and the inability of elected officials to ask questions on reports, council ensured it would be able to ask any questions of the proponent in an open public session.
“I believe it’s important to specify. We don’t need to specify the time they do it, but as part of the contract that they will come back and answer questions of council in a public setting,” said Councillor Paul Ryan after Coun. Lisa Rosvold brought forward the amendment.
“It could be a week or two later and more information could come to the surface from the presentation that wasn’t available as was with the last work that was done.”
The insistence came following the work by McElhanney Engineering, which saw a technical memo submitted on March 10 summarizing the recommendations from the November 2020 physical hydrogeological assessment report.
The aim was to “provide a better understanding of the causes and mechanisms of flooding from water table rise in east Exshaw.”
But McElhanney left the project and a third-party review by BGC Engineering of the debris-flood mitigation design by Golder Associates for Jura Creek had issues raised by members of council earlier this year.
The independent review brought forward issues with the proposed design by Golder, but council was unable to ask potential questions of the third-party review, which brought forward concerns with the project design.
Council had municipal staff prepare a terms of reference for the review and analysis of the McElhanney recommendations at its April 13 meeting.
The flood mitigation became a priority after the 2013 flood. Exshaw and Jura creeks saw runoff water mixed with debris after significant rainfall.
The goal of the project’s work to reduce the amount of flooding for homes on the eastern edge of Exshaw and the third-party review found flooding was likely to increase.
The ongoing request for proposals will allow engineering firms to submit cost estimates, which council will be able to select at its Aug. 24 meeting.
The work will have a selected engineering firm outline the necessary work, data analysis, research and the timeline to undertake the project.
Morrison Hershfield, a Toronto-based consulting firm with offices in nearby Calgary, was also retained to help review the RFP submissions. The company will also assist with the review of the preliminary and final groundwater study plans.
MD of Bighorn CAO Robert Ellis said the funding will come from the municipality opposed to any provincial grants.
The report also highlighted more than a dozen reports between 2009 to 2021 that have information for the review, but Ellis noted it doesn’t stop any company selected by council to do further research.
“This doesn’t limit them. … It’s up to the proponents to look at all the documentation, which does go back to 2012,” he said. “When they make their submission they’re fully knowledgeable of the information available.”
Reeve Dene Cooper said that all the previous studies should be informing this report. "I don’t want any limitations to what can be considered providing the specialists have identified that as relevant information," he said.
Cooper also emphasized there are a number of piezometers – a device to measure the pressure of groundwater – in the municipality, including two on Exshaw Creek and three on Jura Creek.
“That is not a small number of piezometers. There are seven active piezometers at the Francis Cooke landfill, so we have information being taken through this that will be useful for these studies,” he said. “It’s not like we’re getting started. As far as measurement is concerned, we are already started.”
