City looks at options to improve Mill Creek water quality

The city is looking at ways to improve water quality in Mill Creek and prevent more erosion along its banks.

More frequent and severe rainstorms, along with runoff from neighbourhood streets, washes pollution and dirt into the creek, which ultimately feeds into the North Saskatchewan River.

"Anything that's on the road or in yards can end up in the creek," said Kerri Robinson, an engineer in the city's drainage department.

The city will consider various options to deal with the problem, including ponds and wetlands, as well as connecting two major underground storm-water tunnels.

During times of high flow, water would be diverted through to those two tunnels rather than running directly into the creek.

"It's definitely not a cheap fix," Robinson said in an interview on Tuesday. "We're looking in the $50-million range to build the tunnel."

Erosion also increases the amount of sediment that ends up in the creek, and causes the banks to slump.

In recent years, dealing with erosion has become costly for the city, Robinson said.

"Trails falling in, trails having to be abandoned or requiring a lot of extra maintenance to maintain them, bridges being undermined," she said.

A public information meeting is set for Thursday, Nov. 3, from 5 p.m. to 7 p.m. at C3 Church, 9425 76th Avenue.

The city is looking for input from the public on the option of connecting the two storm-water tunnels.

Another option for improving water quality would be the installation of oil and grit separators, which are built underground on the storm-sewer lines, Robinson said. 

A third option would be to install a pond or a wetland just north of Argyll Road, at the bottom of the ravine, between the communities of Avonmore and Argyll.

That area is used as a toboggan hill in winter, and for bicycle races in summer, and the city has already heard from people who don't want to see that area changed, she said.

The project is only at the concept level, Robinson said, and will likely be presented to city councillors in late 2017 or early in 2018.

"We've got a lot of options we've identified as feasible, but whether we go ahead with anything at all is still up for discussion.

"If people don't come out and tell us we love this idea or hate this idea, then decisions will be made without their input. We have a fantastic river valley and ravine park system, and I think it's important for people to have a say in how we maintain that."