Is an Orillia address in a flood hazard area, and whose map says so?

The City's Official Plan directs new development away from flood-prone areas, defines the regulatory flood as the greater of the Regional storm and the 1:100 year storm, and treats the whole floodplain as the floodway. Its Zoning By-law maps Flood Hazard One and Flood Hazard Two overlay zones on Schedule B: in either, no exterior opening to a habitable area may be below 220.5 metres (geodetic), and in the Mill Creek Regional Floodplain no exterior opening may be below 0.5 metres above the highest flood elevation on the lot, with flood-proofing under the Building Code for buildings in a floodplain.

The Zoning By-law names the Lake Simcoe Region Conservation Authority as the conservation authority, and the Official Plan says a permit may be required from it before development or site alteration in hazard lands and wetlands, or changes to watercourses and shorelines, within the Lake Simcoe watershed. The authority's watershed page says that watershed reaches into Orillia, though its planning page's list of the municipalities in its jurisdiction does not name the City; its regulation map viewer shows where its regulated areas are mapped, and it says a municipality may require its own permit for the same work. A flood zone or regulated-area result governs permits; it is not a forecast that a home will flood, and a home outside the mapped area can still take water through a basement.

• Official Plan, consolidated January 2, 2026: the City's natural hazard and floodplain policies, section 4.8 (PDF)
• Zoning By-law 2014-44, consolidated July 27, 2026: section 15.4, the Flood Hazard overlay zones (PDF)
• Planning Documents: the City's page with the zoning schedules and the zoning map
• LSRCA: our watershed: the Lake Simcoe watershed and the municipalities it crosses
• LSRCA: planning: the municipalities within the authority's jurisdiction
• LSRCA regulation maps: the authority's interactive regulation map viewer and its yearly updates
• LSRCA: do I need a permit: what work needs the authority's permit in a regulated area, and its note that the municipality may require one
• Ontario Regulation 41/24: Prohibited Activities, Exemptions and Permits, the regulation behind every conservation authority's regulated area

Conservation-authority regulated-area and flood plain checks are not currently included in our reports, so for an Orillia home the City's zoning schedule and the authority's own map are the places to look. The full report's water and flooding group does cover past floods seen by satellite, nearby creeks, rivers and ponds, and mapped wetlands for any Orillia address.

What we cover, city by city See the sample report