There is likely a number of federal, provincial, or municipal legislation and policies regulating the proposed development, which would require approval prior to work starting. Federally, the fish habitat protection provisions of the Fisheries Act are administered by the Fish and Fish Habitat Protection program within Fisheries and Oceans; more information can be found on their website
https://www.dfo-mpo.gc.ca/pnw-ppe/ffhpp-ppph-eng.html. Provincially, they would require a permit under the public lands act which is issued by the MNRF (see
https://www.ontario.ca/page/crown-land- ... its-policy).
Hope that helps