Vernon Creek can't keep up to climate change; naturalization to foster return of salmon

The channelizing of Vernon Creek through Polson Park was done decades ago to control flooding.

But it's no longer able to do its job, thanks to climate change.

During a recent presentation to the Okanagan Basin Water Board, City of Vernon water resources engineer Mathew Keast discussed plans for the naturalization of the creek.

These will include dismantling the concrete channel and returning the creek to a meandering path.

Keast explained although the channeling was done to address flooding, it was designed to a one-in-100 year event standard.

With climate change, the city is seeing "higher and more intense flows," and the channeling is no longer working, he said.

City staff are developing a master plan for the creek that will include public consultation this year and next.

The first phase of the work is expected to begin next summer, at the flood-prone Highway 97 side of the park. The second phase will include the development of multi-use paths and crossings.

"Once work is ready to begin, naturalization will be the first step, including removal of concrete barriers, adding riparian planting and re-engaging the floodplain," said a statement in the water board minutes.

The naturalization is expected to foster the return of spawning kokanee, trout, and sockeye salmon, in conjunction with work by the Okanagan Indian Band and Okanagan Nation Alliance.

A City of Vernon report stated natural features such as riffle pools and boulders will be added to "increase natural fish/spawning habitat where there is currently very little."

"Naturalizing the channel will increase water quality, increase fish habitat, increase riparian complexity and decrease groundwater impacts on park operations," the report stated.

"Naturalizing the channel will also include a floodplain on either side of the main channel to accommodate larger flooding events. The channel will have shallow slopes and will be planted with natural riparian vegetation and bank armouring to prevent erosion."

A contractor is expected to be hired this fall, with construction beginning in July next year.

The report noted the park has seen "longstanding problems with high groundwater and water ponding."

The water board is partially funding the project, along with funds from the city's casino grant reserve.