The Fisheries Act is federal legislation protecting fish and fish habitat across Canada. Key provisions prohibit serious harm to fish that are part of commercial, recreational, or Indigenous fisheries, and regulate deposits of deleterious substances into waters frequented by fish. For municipalities, the Fisheries Act affects infrastructure projects near waterways: culvert replacements, bridge construction, stormwater outfalls, and development near streams may require federal authorization if they affect fish habitat. Wastewater discharge must meet federal regulations to avoid harming fish. Non-compliance can result in significant penalties. The Act requires proponents to avoid or minimize impacts on fish habitat and may require offsetting measures to compensate for unavoidable impacts. Municipal staff working on infrastructure projects near water must understand Fisheries Act requirements early in project planning to avoid delays and ensure compliance.