Against environmental odds, Katzie Slough has salmon, a new report has found, and allowing the City of Pitt Meadows to clear the waterway will not only stop flooding in the area, but improve it as fish habitat.
The finding was in a report titled the Katzie Slough Fish Habitat Inventory Assessment, which was recently delivered to Pitt Meadows city hall. The goal of the study was to come up with a maintenance plan for the slough, while satisfying the Department of Fisheries and Oceans that fish habitat is being protected.
A highly engineered urban stream, the slough is a desolate environment for fish. Some sections are almost completely dry during summer. Other reaches are so choked with canary grass and weeds that the water doesn’t move, raising temperatures and lowering the amount of dissolved oxygen in the water, especially in the summer.
There are also few trees along the banks to shade the watercourse.
The report, prepared by ISL Engineering of Burnaby, noted that during the summer, the slough does not meet Ministry of Environment guidelines for salmonid habitation.
However, like dandelions growing through cracks in the sidewalk, salmonids were found there.
Subcontractor Scott Resources of Mission set 699 minnow traps, each for a 24-hour period, during all four seasons. They managed to catch 23 coho salmon and five cutthroat trout – another salmonid.
“It shows the resilience of the salmonid species,” said Greta Borick-Cunningham of the Alouette River Management Society, which does habitat monitoring in a 300m channel of the slough.
“It’s great to see that.”
She said the new report reaffirms the importance of habitat restoration projects.
There were 11 total species of fish trapped, but the most common was the threespine stickleback – a hardy, 5 cm long fish that can live in a variety of conditions from coastal salt water to ditches, and named for the spikes sticking out of its back. There were more than 13,000 of them caught in the slough.
The report calls the slough winter habitat for salmonids, and year-round for other species.
Defining the fish values in the slough was important, said Kim Grout, Pitt Meadows director of operations and development services. She points out that it will not be real fish habitat until the infrastructure of the slough is upgraded.
“Those fish live a very challenged existence,” she said.
Virtually all of Pitt Meadows would be under water if not for the system of dikes and pumps that surround it. The pumps, installed in the late 1940s, kill adult fish that pass through them. There are six pump stations with 15 pumps, and each pump cost $4 million to replace, are nearing the end of their life cycle.
Pitt Meadows Mayor Deb Walters said replacing them is a high priority, as grants from senior government are made available. New pumps are designed to be “fish friendly.”
She said the report should help the city maintain the slough, removing sediment and vegetation, and maintaining the banks. That will eliminate the nuisance of flooding, which effects farm fields and even some basements in Hammond.
“I’m hopeful now that we’ll have a window of opportunity to clean it out,” said Walters. “You have to keep the water flowing.”