As part of the delivery of programs and services related to natural hazards, Conservation Halton develops natural hazard and wetland mapping, policies, and technical guidelines. Through the process of developing these products, we engage with the people who live, work and/or have an interest in our watersheds, including residents, landowners, Indigenous communities, developers and municipal and provincial partners. We provide opportunities for people to offer feedback on our programs and services through public engagement on specific studies or initiatives as well as draft mapping, study findings and policies. Public involvement provides greater certainty and transparency on Conservation Halton programs and services, and we benefit from receiving observations about the watershed from the people who experience these watershed conditions.
Public Notice:
In partnership with the Town of Oakville, Conservation Halton (CH) is undertaking a study to update flood hazard modelling and mapping within Kent Gardens, the QEW Corridor, Midtown Oakville Growth Area and adjacent areas. Conservation Halton regularly reviews and updates flood hazard modelling and mapping to fulfill the requirements under the Conservation Authorities Act.
Get Involved
Join us for a virtual public engagement session on May 7, 2025 at 7:00pm to learn more about the study findings, ask us questions, and share your feedback.
Register for the virtual public engagement session here.
Draft mapping and reports, as well as a recording of the public engagement session, will be available online for public review and comment for 30 days until June 6, 2025.
After the public engagement session and 30-day public review period, CH will review all feedback received and make any necessary revisions to the draft flood hazard mapping. The final draft mapping and study will be presented to CH’s Board for approval and will be included in CH’s online Approximate Regulation Limit (ARL) mapping later this year.
Presentation material from the first public engagement session hosted on October 24, 2024 is available here.
If you have any questions about this study, please email floodplainmapping@hrca.on.ca.
Why Flood Hazard Mapping is Important
Riverine flood hazard mapping is an important tool that supports CH’s regulatory, planning and flood forecasting and warning programs. This information also supports municipal emergency management planning, flood mitigation and infrastructure design.
Riverine flood hazards include flood plains and spills. A flood plain is an area of land that is flooded with water from a nearby creek during large storms. Spills occur when flood waters leave the valley and flood plain and “spill” into surrounding lands, rejoining the watercourse at a distance downstream or moving into another watershed. Flood hazard mapping uses models to predict where riverine flooding will occur and the extent of riverine flood hazards in a given area. Flood hazard mapping does not create a flooding hazard — it shows where the hazard already exists.
Spill Flood Hazard Policy Review: Background
Under the Conservation Authorities Act and Ontario Regulation 41/24, Conservation Halton (CH) regulates development in riverine flooding hazards (floodplains and spill flood hazards or “spills”). Spills occur when floodwaters leave a watercourse, its valley and floodplain, and continue to flow overland in multiple directions before rejoining the same watercourse downstream or spilling into another watershed. Spills often move through areas where riverine flooding may not be anticipated and can flow in complex patterns.
In March 2022, CH shared a discussion paper as the initial stage of the spill policy review and update process to provide the public and stakeholders with background information and to engage on the policy approaches that CH could take to deal with development in spills.
In November 2022, CH’s Board endorsed the Spills Flood Hazard Policy Directions Report, which includes an overview of the feedback received on the discussion paper and staff’s recommended policy approach and direction for managing risk associated with development in spill flood hazards along with supporting rationale.
In September 2024, CH’s Board endorsed proposed draft spill flood hazard policies and a supporting technical companion document for public engagement. The draft policies and technical companion document were created following the directions previously endorsed by the CH Board and are based on a risk-based approach to guide development activities within spill flood hazards. For more information about our policies and the supporting rationale please refer to the staff report (page 38).
Spill Flood Hazard Policies and Technical Guide
On April 17, 2025, CH’s Board approved the spill flood hazard policies and technical guide. For more information, please refer to the staff report.
CH would like to thank those who participated in public and stakeholder engagement events and/or provided written feedback. All feedback received and CH’s response is available here.