Cache Creek Flood Mitigation Plan

In 2021, following five years of almost annual flooding events, the Village of Cache Creek undertook a comprehensive, long-term flood mitigation plan and several infrastructure projects to mitigate community flood risk. Hydraulic modeling was developed for floodplain mapping with flood inundation limits, delineation of floodplain boundary, and determination of flood construction levels. Using this mapping, adaptation strategies were developed for a 10-year plan. Strategies were categorized as “non-structural” mitigation measures, which included development policies and identification of additional studies needed, or “structural” mitigation measures, which included a list of priority infrastructure projects. Several structural mitigation measures are currently being designed and implemented. One project consists of regrading and installing culverts on a stretch of Old Cariboo Road, which is vulnerable to flooding and debris accumulation. The other project will protect the vulnerable drinking water facility. Cache Creek has also become a leader in emergency management with neighboring communities looking to them for advice and guidance on deploying emergency equipment.


Identifying Actions

In 2021, the Cache Creek received funding to undertake a Flood Mitigation Plan. The plan will ensure the village has a thorough understanding of the current and future flood risks and provide access to updated information to better respond to flooding events when they do occur. It provides them a list of priority projects for future budgets and grant proposals for implementation of the plan, including capital projects aimed at developing a more resilient community. As part of the plan, hydraulic floodplain mapping was undertaken using 200-year flows. The mapping included flood inundation limits, delineation of floodplain boundary, and determination of flood construction levels. Using this mapping, adaptation strategies were developed for a 10-year implementation plan. Strategies were categorized as either “non-structural” mitigation measures or “structural” mitigation measures. Non-structural mitigation measures include CCTV survey of sanitary sewer system, updates to the Official Community Plan to include floodplain mapping, creating a floodplain bylaw (setback and flood construction level for new development), and preparation of a flood response plan. The structural mitigation measures projects include further improvements to the drinking water system, sanitary system improvements, and various improvements to the Cache Creek Corridor to convey a 200-year flow.

Implementation

Concurrent to the development of the Flood Mitigation Plan, two projects were identified for immediate priority action and will be completed by 2022. The first project is to manage debris flow along Old Cariboo Road. The improvements include regrading approximately 170 metres of road, installation of new culverts, and bank restoration and erosion protection. The work will be concentrated around the Riverside Mobile Home Park, which has been severely impacted by flood events. Old Cariboo Road will be regraded so the road slopes away from the Riverside Park towards the hillside, redirecting water toward the ditch at the base of the cliff and away from the park. A swale will be installed to redirect water overland and into the Bonaparte River if the culvert becomes blocked. In 2021, grant funding was also obtained to protect the drinking water facility in Cache Creek. Along with reinforcing one wellhead and decommissioning a wellhead and replacing it with a more resilient wellhead, over 300m of roadway will be raised to ensure safe access during high water events. Additionally, several infrastructure improvements were made to the facility itself and remote digital access to facility systems was implemented.

Outcomes and Monitoring Progress

Individual projects will be monitored for effectiveness following full implementation. Despite the challenges the Village of Cache Creek has experienced over the last five years, the residents have come together to address issues, leading to a strong sense of community and a high level of climate literacy and emergency preparedness. Residents track extreme weather events and recognize the significant cost and financial implications that climate change is bringing. Cache Creek has also become a leader in emergency management with neighbouring communities look to Cache Creek for advice and workshops, and for guidance deploying emergency equipment.

Next Steps

The Village of Cache Creek Flood Mitigation Plan is being finalized with community consultation. They will continue to undertake non-structural flood mitigation measures annually as their budget allows and pursue funding assistance for the structural flood mitigation measures. The plan provides a roadmap for the village to continue to improve their resilience to climate change impacts over the next 10 years. Furthermore, it will be an important tool for enhancing emergency management.