Though the province provides online mapping of wetlands (many conservation authorities offer their own maps on their websites as well), it’s not exactly an easy tool to use if you’ve never used it before.
Here’s the simplest way to make it work for you. Go to this URL: www.ontario.ca/page/make-natural-heritage-area-map.
Click on make a natural heritage map.
Once the page has loaded and you’ve accepted the disclaimer, click on Map Layers, then click on Select Map Layers, then click Wetland. You can then click on Find Information, click Search By Location, and choose a type of location to search by.