18-Env-B2 Water Resources · May 2016
Nivaar worked solution (AI-drafted; not reviewed by a licensed engineer)
National Exams — May 2016 — 04-Env-B2 / Water Resources. 3 hours duration; closed book; Casio or Sharp approved calculator only. Six Problems are printed; any five constitute a complete paper (the first five answered are marked). Each Problem is worth 20 marks. All six are solved below for completeness.
Reference texts. Linsley, Kohler & Paulhus, Hydrology for Engineers (3rd ed.); Chow, Open-Channel Hydraulics; Freeze & Cherry, Groundwater; Davis & Cornwell, Introduction to Environmental Engineering (6th ed.); Ontario Ministry of the Environment, Stormwater Management Planning and Design Manual (2003); Fisheries Act, Ontario Water Resources Act, Clean Water Act, 2006 (Ontario).
Question text not reproduced: the examination questions are © Engineers and Geoscientists BC. Open the official past paper (linked at the top of this page) to read the question, then follow the worked solution below.
Stormwater discharge quality in Canada is governed by an overlapping web of federal and provincial legislation, since the receiving watercourse, the fish it supports, and the land the runoff crosses each fall under a different jurisdiction. Six statutes together set the legal framework a designer must satisfy before an outfall can discharge to a receiving water (the paper's Ontario context is used below, per the standing rule that provincial examples follow the paper's own jurisdiction):
| Legislation | Jurisdiction | Relevance to stormwater management |
|---|---|---|
| Fisheries Act | Federal | Section 35/36 prohibits serious harm to fish and the deposit of a deleterious substance into water frequented by fish — the primary federal backstop against contaminated stormwater discharge to a fish-bearing receiving water. |
| Canadian Environmental Protection Act, 1999 (CEPA) | Federal | Regulates toxic substances across their life cycle; can restrict the manufacture, sale, or discharge of substances (e.g., certain metals, PAHs) commonly found in urban stormwater. |
| Impact Assessment Act, 2019 | Federal | Triggers a federal environmental assessment for designated projects with the potential for significant effects on water resources, including major stormwater infrastructure. |
| Ontario Water Resources Act (OWRA) | Provincial (Ontario) | Prohibits discharging any material into water that may impair its quality, and requires an Environmental Compliance Approval (ECA) for stormwater management works and permits to take water. |
| Environmental Protection Act (Ontario EPA) | Provincial (Ontario) | General prohibition on discharging a contaminant that causes (or is likely to cause) an adverse effect; underpins spill-reporting and pollution-prevention obligations for stormwater facilities. |
| Conservation Authorities Act | Provincial (Ontario) | Requires a permit for development, interference with a watercourse/wetland, or alteration to a shoreline or floodplain, so new stormwater outfalls and SWM ponds are directly reviewed under it. |
In practice these six instruments are complementary rather than redundant: the Fisheries Act and CEPA set a federal quality/toxicity floor that applies everywhere; the OWRA and Ontario EPA give the province the approvals and enforcement tools (ECAs, orders) to hold a specific municipal or private stormwater system to that floor; and the Conservation Authorities Act adds a local, watershed-scale review of where and how a new outfall or pond may be built relative to the receiving watercourse and its floodplain. A stormwater management plan that satisfies only one layer — for example, an OWRA-approved SWM pond that nonetheless discharges a deleterious substance — remains exposed to enforcement under the layer it missed.
