Developing and Deploying a One-Water Planning Approach for the Cambie Corridor

The City of Vancouver, British Columbia, is working to develop an integrated or 'one water' approach to delivering water-related infrastructure (i.e., potable, sanitary, and stormwater) to the Cambie Corridor, a rapidly developing transit corridor south of downtown. The current water-related infrastructure is beyond capacity; and a recent land-use plan for the 1,000-hectare corridor revealed that the population living and working there is expected to more than double in the coming decades. These land-use pressures along with climate change and ecosystem health concerns necessitate a fresh, holistic look at all forms of water infrastructure serving the corridor. To create a plan for the corridor, the City used a collaborative engagement process to develop a water-servicing vision and a multi-benefit assessment approach for evaluating one-water opportunities (i.e., programs, policies, and projects). Opportunities include various types of distributed green and blue-green stormwater infrastructure, regional green stormwater management facilities, water conservation and efficiency strategies, site and district scale non-potable water reuse (e.g., rainwater, greywater, and foundation drainage), and policies and programs to mandate, incentivize, and/or encourage private investments and partnerships. The assessment approach, which will be the focus of this presentation, was used to identify, value, screen, and ultimately optimize the suite of opportunities needed to meet the City's objectives. The assessment approach included several analytical tools working in tandem, including (1) a custom-built Water Balance Model paired with a calibrated hydrologic and hydraulic model to evaluate opportunity performance, (2) a GIS tool to help site opportunities, (3) a Decision Support Tool to value ecological and community co-benefits and measures of reliability and feasibility, (4) a scenario planning analysis to account for risks and future uncertainty, and (5) an optimization tool that uses advanced statistical algorithms to identify the ideal combination of opportunities that meets water-servicing targets, minimizes costs, and maximizes co-benefits. This assessment approach allowed the City to balance the trade-offs inherent in a multi-objective analysis in a defensible, transparent, and easy-to-understand way. The effort culminated in development of a high-level long-term water servicing strategy for the corridor and a more detailed short-term capital plan for investments in the next 4 to 8 years.