There are now over 150 species with general habitat protection under the Endangered Species Act ("ESA"), of which 22 species are also subject to species-specific regulation.

Habitat protection affects landowners, developers and proponents of infrastructure in Ontario. Even approved projects may be affected, subject to transition rules.

The ESA regime allows for five types of permits: overall benefits permits, health or safety permits, protection or recovery permits, social or economic benefit permits, and aboriginal permits. The most relevant permit for infrastructure and private sector development projects is the overall benefits permit which allows a party to perform an activity not otherwise allowed under the ESA in exchange for demonstrating an overall benefit to the species in Ontario. Notably, the benefit must occur in Ontario and not specifically where the harm has occurred.

New transition rules permit "streamlining" procedures, and exemptions have also been introduced by regulation. In some cases, projects may proceed with permits, provided that mitigation plans are prepared in accordance with the regulation.