Is a Woodstock address in a regulated flood area, and whose map says so?

The Upper Thames River Conservation Authority names Woodstock among the larger urban centres of its watershed and the City of Woodstock among its 17 member municipalities. Its regulated area map, online at maps.thamesriver.on.ca, shows the approximate regulated area; its flooding hazard is drawn for the 1937 flood event standard, a 1:250-year flood, and on 6 October 2026 its board approved updated maps for the South Thames from Pittock Dam in the City of Woodstock downstream to London, which it says will reach the online map within 30 days. The Grand River Conservation Authority's Map Your Property tool also lists Woodstock among its municipalities; it says not every regulated area may be mapped and that the regulation applies whether an area is mapped or not.

Section 5.1.6 of the City's Zoning By-law 8626-10 says no building may be put up or used on hazardous land where conservation authority regulations are in effect without a permit or other permission from the authority having jurisdiction, and Table 3A keeps additional residential units out of the Regulation Limit on Schedule A unless the authority approves. The Grand River authority says its permit is in addition to a building permit from the municipality, and the Upper Thames authority leaves it to the applicant to give the City a copy of its permit where one is needed for a building permit. A 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. Under the Conservation Authorities Act as amended in 2026, the Upper Thames River authority is to join the Western Lake Erie Regional Conservation Authority, and the Grand River authority the Eastern Lake Erie Regional Conservation Authority, on 1 February 2027 or a later date set by regulation.

• UTRCA: about us: the Upper Thames watershed and its urban centres, Woodstock among them
• UTRCA: board of directors: the authority's 17 member municipalities
• UTRCA: regulated area maps: the online map, the 1937 flood standard and the 2026 South Thames update
• UTRCA: how to apply for a permit: the authority's permit process
• GRCA Map Your Property: the Grand River Conservation Authority's map of its regulated area, by municipality
• Zoning By-law 8626-10, section 5: section 5.1.6, Conservation Authority Regulation Limit, and Table 3A (PDF)
• Bill 97, Plan to Protect Ontario Act (Budget Measures), 2026: Schedule 3 amends the Conservation Authorities Act; the transition date is 1 February 2027 or a later date set by regulation
• Regional conservation authority boundaries (ERO 025-1257): the Province's decision of 10 March 2026 on which authority joins which of the nine regional authorities
• 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 a Woodstock home the authority's own map is the place 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 Woodstock address.

What we cover, city by city See the sample report