Conservation Halton is redrawing Oakville's flood maps along three creek systems, and wants residents' flooding observations by December 14
Three studies now cover Fourteen Mile and McCraney creeks, the eastern reaches of Sixteen Mile Creek, and the Sixteen Mile-to-Lower Morrison corridor through Kent Gardens and Midtown. The new maps will set where the authority regulates building.
The details
What is happening
Conservation Halton, the authority that regulates building near creeks, valleys, wetlands and the Lake Ontario shoreline in Oakville, has three separate studies under way to update the flood hazard modelling and mapping that underpins those rules. The authority says it regularly reviews its mapping to meet Ontario Regulation 686/21 and Ontario Regulation 41/24 under the Conservation Authorities Act.
The newest notice concerns Fourteen Mile Creek and McCraney Creek. Conservation Halton is working with Onterris, an engineering consulting firm, on a study area that covers southwest Oakville, parts of south Milton and east Burlington, and runs downstream to Lake Ontario. Residents who have seen flooding in the area are asked to complete a short survey, which closes on December 14, 2026. The authority says it will hold a public engagement session in late 2026 and present the study results at a final session in 2027.
The three studies
- Southwest Oakville, south Milton and east Burlington to Lake Ontario. Survey open to December 14, 2026; public session late 2026; results in 2027.
- Eastern reaches of Sixteen Mile Creek in Oakville, Milton, Halton Hills and Mississauga. First session held November 27, 2025; draft methodology report commented on January 13 to July 15, 2026; draft maps to be presented in 2027.
- With the Town of Oakville: Kent Gardens, the QEW corridor, the Midtown Oakville growth area and adjacent lands. No dates published yet.
- The Fourteen Mile/McCraney and East Sixteen Mile studies are funded in part by Natural Resources Canada's Flood Hazard Identification and Mapping Program and the Province of Ontario.
Why the maps matter
Flood hazard maps are the basis of Conservation Halton's permitting. Anyone proposing development within a regulated area, which includes flood plains and the lands next to them, needs the authority's permission. The maps also feed its flood forecasting and warning work, and the Town uses them for emergency planning, flood mitigation and infrastructure design.
The authority maps two kinds of hazard. A flood plain is land that floods from a nearby creek or lake during large storms. A spill occurs when flood water leaves the valley and flows across surrounding land before rejoining the creek downstream or crossing into another watershed; the portions of a spill considered unsafe to build on are mapped as a spill flood hazard. Updated maps can move properties into or out of either category.
How to take part
- Fourteen Mile and McCraney Creek: complete Conservation Halton's online survey before December 14, 2026, or sign up for study updates on its Public Notices and Engagement page.
- East Sixteen Mile Creek: the formal comment period has closed, but the authority still accepts observations through its feedback form ahead of the 2027 session.
- Questions on any of the studies go to floodplainmapping@hrca.on.ca.
What happens next
Done: Study launched
Conservation Halton and Onterris begin updating the flood models.
Now: Resident survey
Open until December 14, 2026; public engagement session planned for late 2026.
Next: Final session
Study results presented in 2027; updated maps then set the regulated area.
Sources
Conservation Halton
Public Notices and EngagementConservation Halton
Mapping and StudiesTown of Oakville
Environmental Projects and Studies — Flooding studies
