Ontario's conservation authorities manage watersheds across the province. Under the Conservation Authorities Act, and since April 2024 a single provincial regulation (Ontario Regulation 41/24), they regulate development in and near natural hazards: shorelines, rivers and creeks, floodplains, valleys and steep slopes, and wetlands.
Does It Apply to Me?
Each conservation authority publishes mapping of its regulated areas, usually as an online map you can search by address. If part of your property is inside a regulated area, work there, such as an addition, a deck, a garage or significant grading, may need a permit from the conservation authority. Interior renovations usually do not.
How It Fits With the Building Permit
The municipality generally will not issue a building permit until any required conservation authority permit is in place. That makes it the first approval to sort out, not the last.
What They Look At
The questions are about risk: is the new work out of the floodplain, is it set back from an eroding slope or shoreline, will it affect a wetland or watercourse, and will it change how water moves on the site. Sometimes the answer is a modest change in footprint or elevation.
Building Near the Water
Decks, additions and renovations near water also face more moisture, ice and wind than inland homes. Fasteners should be hot-dip galvanized or stainless, decking should resist rot, and basements need reliable drainage and a working sump.
How to Avoid Delays
Check the mapping for your address before design begins. If the property is regulated, contact the conservation authority early. Many offer pre-consultation, which can save a round of revisions later.
