The leaking pipe which surprised the construction crew during construction of the McKenzie interchange last week has been identified as a draining pipe from the Burnside neighbourhood.
“The broken pipe had a surcharge of water stored inside that released and overwhelmed the containment area,” said Harley Machielse, Saanich director of engineering.
A conservative estimate had thousands of gallons of sediment running into the Colquitz River over the past week. The threat is that ongoing sediment turbidity in a river can be a serious threat to the aquatic life, especially the spawning salmon and other fish currently in the Colquitz. It also happens to be a boon year for the Colquitz fish fence, with more than 1,120 spawning coho already counted. Migrating fish on their way to the fish fence are at risk, especially if the turbidity is consistent.
The pipe was thought to have been discharging farther upstream of the wetland area between the soccer fields of the schools (St. Joseph’s, Spectrum, Marigold) and the highway, Machielse said. Saanich’s role was to help identify the pipe which was unmapped and therefore unknowingly uncovered by Jacob Bros. construction as they worked to establish a new grade for the massive project.
Janelle Erwin from the Ministry of Transportation and Infrastructure is the project manager for the McKenzie interchange. She said the crew immediately ordered an additional filtration system and had it implemented by Saturday. As of Wednesday morning, crews and Saanich were still trying to establish where the storm water would best be released.
Not helping the matter was an abnormally high weekend downpour of 29 millimetres, as recorded by the Island Based Weather Network station at nearby Tillicum elementary.
“Certainly our contractors monitor for anticipated rainfall,” Erwin said. “That said, with heavy rainfall we still need to have the necessary measures in place, and we do, but it makes it more challenging.”
The rain and drain pipe have led to excess water and sediment gathering along the silt fence put in place for the construction in the former Cuthbert Holmes Park. A second silt fence has been installed after the initial fence was unable to capture the excess runoff from the construction site.
“It’s an additional redundancy measure, as well as the pump, that should collect the water, so that ultimately the water leaving our site is clear and not carrying sediment,” Erwin said.
Longtime steward for the health of Cuthbert Holmes Park and Colquitz River Dorothy Chambers witnessed what she called a “serious breach of the sediment fencing… and a river of mud flowing directly into the Colquitz River,” on Monday morning.
Victoria-Swan Lake MLA Rob Fleming visited the fish fence that morning and walked through Cuthbert Holmes with Chambers and members of the Gorge Tillicum Community Association.
Chambers was unable to locate an environmental monitor on Monday but Erwin said there will be a third-party environmental monitor on site 24-7, to make sure MOTI has a really good understanding of what’s happening with the runoff and to make sure the additional fencing is working.
Fleming said the flow of water through the sediment runoff was so strong on Monday you could hear it flowing into the tributaries just metres away from Colquitz, which itself is now the colour of chocolate milk. And that was about 15 hours since the last of the heavy rains, he added.
“People were promised that this project would be done to the highest environmental standards, it’s at the edge of a highly sensitive park,” said Fleming, who was concerned over the response time. “We’re just getting started and already this looks like it could be impacting salmon up the Colquitz River.”
Saanich Coun. Colin Plant also announced his concerns on social media but stood behind Saanich’s efforts to support the province as it works to minimize the ongoing turbidity of the river.