Technology assists City with annual freshet preparations
With spring in full swing, the annual freshet in the Okanagan is on its way.
“Freshet is the annual snowpack melt that typically occurs from April to July in our province. Freshet can become an issue when the winter snowpacks melt rapidly, or when heavy spring rains add to the snowmelt, overwhelming our streams and causing flooding,” said Rod MacLean, Utility Planning Manager. “At this time of year, we’re always on standby, monitoring our own systems and working with provincial departments and Environment Canada to monitor all of the factors that lead to overwhelming freshet flows and to inform planning activities. In recent years we are seeing nature become more and more unpredictable.”
The City’s monitoring systems include newly installed flow measurement data stations. Over the past two years, four stations have been installed along Mill and Mission Creeks capturing real-time flow and climate metrics to help identify potential debris blockage or overflow. The level sensors at the Mill-to-Mission Creek diversion also remain in place as safeguards.
The City has added the new gauges to its digital dashboard and is continuously collecting and refining the flow data. The more data that is collected and processed, the more accurate the ultimate output becomes. And more accurate output means better predictive modelling to help address what could happen not only through freshet season but also as we navigate the effects of climate change.
Since the 2017 floods, the City has made significant investments in flood mitigation along Mill Creek.
- The capacity of Mill Creek was increased by removing dead trees, vegetation, and obstructions within the channel;
- Replacement trees were planted in fall 2019 and placed well above the natural boundary. Restoration of the riparian values along the channel is essential in preserving stream health, fisheries values, and water quality;
- Damaged culverts were repaired and replaced. New designs favour arch culverts for larger creek crossings. The culvert at Spencer Road was the latest to be completed near Mill Creek Regional Park.
- In 2020, we worked with residents to remove privately-owned footbridges that were a source of debris risk;
- After the freshet in 2021, the Mill Creek Flood Protection Project will start with construction with new diversion upgrades.
Our best information to date is that the snowpack in key watersheds is lower than at this time last year which generally indicates that widespread flood risk is low. But as we have experienced in the past, the weather is unpredictable and with just the right mix, localized flooding is always a possibility and property owners should be prepared.
Property owners are responsible for protecting their own properties. Sandbags are available at the Kelowna Fire Hall on Enterprise Way and sand is available for purchase at most local nurseries and gravel pits.
As it does every year, the City is preparing its sand and sandbag stocks. If the data indicates a high potential for flooding, sand and sandbags will be strategically placed in specific neighbourhoods. Depending on flows and risk for flooding, other preventative measures including sandbags or bladder dams, or pumping stations, may be proactively implemented along strategic locations throughout the city to protect infrastructure.
Residents are encouraged to visit the CORD Emergency website to sign up for e-updates and learn more about preparing for an emergency.
If sand and sandbags are required for residents in the City of Kelowna, an announcement will be made, and the locations will be posted on kelowna.ca.