Conservation Authorities are responsible for floodplain management. Floodplain management helps to:

• Guide sensitive land use away from high-risk areas
• Identify ways to mitigate flood risk where historical development has already occurred
• Protect people, property, and the resilience of our urban areas

Floodplain mapping is used by municipalities in preparing official plans and zoning by-laws, which guide future development in their jurisdiction. Knowing the extent of the floodplain is an important tool for both land use planning and emergency management.

Conservation Authorities are also required to protect wetlands. Wetlands provide important fish and wildlife habitat and act as water storage facilities, holding water back during periods of high water and releasing water during periods of drought.

Interactive Mapping

The CommunityPAL interactive map will help you learn if all, or part of your property is regulated by the MRCA.
Note: Map lines are approximate and there may be some regulated areas which have not been mapped. It is important to know that our regulations still apply. It is always best to contact our office before beginning any work to confirm if you will require a permit. You may still be in a MRCA regulated area —even if you are outside the floodplain.

To determine if your development will be in a regulated area, use the Community PAL interactive map to search for your address. This online mapping provides information about our regulated areas, including floodplains and wetlands.

PLEASE NOTE: The map viewer depicts riverine floodplain extents only. It does not refer to flooding caused by local drainage capacity constraints (urban flooding).

Using the mapping tool

Properties with shaded blue areas are within MRCA regulated areas.

The red lines indicate currently mapped floodlines.

• When the map opens, use the search tool at the top of the map.
• Put your address in the Find Address box located at the top of the screen.
• You can also zoom in or out of the map using the scroll wheel on your mouse to locate your property.

Frequently Asked Questions

What is a 1:100 year flood?

A 1:100 year flood is a major flood that risks causing serious damage to people and property. These major floods have a 1% chance of occurring in any given year. To compare, a 50 year flood has a 2% chance of occurring in any given year. Simply because a major flood occurs does not mean that it cannot reoccur the next year.

What does it mean if my property is in a regulated area?

If the map shows your property within a regulated area, you will need a permit for any development, construction or site alteration (grading, fill placement, excavation, etc.). This is in addition to a building permit or other approvals from the municipality and other agencies. More information about your regulated property can be obtained by filling out and submitting a Property Information Request.

Why is there development in flood areas?

There are many flood-vulnerable structures located in the floodplains on properties within MRCA’s jurisdiction, either because they pre-date floodplain management planning policies and regulations, or because they were permitted under special policy and planning provisions. Ontario is a province with many rivers and lakes and a lot of development was already in place prior to the establishment of regulations.

Additional Mapping

The Ministry of Natural Resources and Forestry also offers Natural Heritage Mapping where you can map local wetlands and woodlands.