The final report into what caused one of the city’s main water arteries to burst this summer will be presented to council today.
When the Bearspaw south feeder main broke on June 5, it prompted a local state of emergency, threatened the city’s potable water supply and led to various levels of water restrictions for Calgary and surrounding communities for months afterward.
While the initial break took weeks to fix, with emergency parts arriving from as far away as San Diego, the crisis also unveiled chronic issues with the pipe itself. This led to several other hot spots being identified as in need of urgent repairs.
Early estimates have put the total cost of repairs at about $40 million.
Soon after the break, the city ordered a third party review of what led to the deterioration and ultimate failure of the pipe.
“I know that this review will go a long way to providing both answers and transparency for the public,” Mayor Jyoti Gondek said in a news conference at the time.
On Tuesday, though, Gondek was critical of how the process unfolded.
“We gather all kinds of information, and then we set about the business of writing a report … and until that report is done, we don’t hear anything about it. I think that’s got to change,” she said.
“If there’s anything that we’ve learned this summer, you have to get information out to people as you know it, and hanging on to things until we have a report to submit is a habit that we’re going to have to break.”
Preliminary findings of the report — which is being overseen by Pure Technologies Ltd. and Associated Engineering — suggest the breaks occurred for several reasons, including:
- Microcracking along the protective mortar outer layer of the pipe.
- High chloride levels in the soil at various locations.
- Snapped wires following corrosion and hydrogen embrittlement.
The investigation also found that the design of the pipe was consistent with accepted guidelines at the time it was constructed, and that its use and operations were within its design parameters.
Built in 1975, the feeder main, which is 11 kilometres long and as wide as two metres in parts, is an integral part of Calgary’s civic water system.
It transports roughly 60 per cent of the city’s treated water supply.