Track 1 Day 1: Longstaff Bambic


Watershed-scale, Cost-benefit Optimization of Stormwater Infrastructure

Wednesday March 25, 2020
4:00 to 4:30 p.m. (Hall A)


Stormwater management (SWM) is an increasingly complex challenge for all municipalities across Canada. Significant challenges relate to insufficient resources, ageing infrastructure, areas lacking stormwater infrastructure, and poor planning. Combined with continued urbanization and climate change, we are witnessing an unprecedented increase in issues such as flooding, erosion, and water quality impairment.

There is a growing consensus that significant and broad, sweeping changes to stormwater management are needed to address the challenge. Critical to the required paradigm shift in stormwater management is ensuring that it is managed at a watershed scale and optimized for the greatest environmental outcomes at the highest cost efficiency.

Optimization may be achieved through the economic concepts of scale, aggregation, integration, and equitable responsibility.

A three-year pilot project within the East Holland River, Ontario, applied a continuous simulation model (LSPC), integrated with the US EPA model SUSTAIN. Using LSPC-SUSTAIN, thousands of stormwater management scenarios are modelled to assess the economic concepts under different development, climate, and planning scenarios.

These findings will be used to secure policy shifts in support of whole-system, nature-based, integrative and transformative planning and design of SWM infrastructure.

This presentation will provide an overview of the study methods, results, implications, and next steps.


Learning Objectives

1. Provide the audience with context as to why the stormwater management optimization pilot project was initiated and why the proposed approach was taken.

2. Provide the audience with an understanding of the methods applied including current and future state modelling, life-cycle costing of stormwater management features, flood damage assessment, and scenario development.

3. Provide the audience with a summary of study results, identifying how the project was able to cost-optimize grey and green stormwater management opportunities across the watershed.



Ben Longstaff

Ben Longstaff

Ben Longstaff is General Manager of Integrated Watershed Management with Lake Simcoe Region Conservation Authority (LSRCA). In this role, he provides leadership, support, and strategic direction to the Conservation Authority’s watershed planning, climate change, source water protection, urban restoration, and environmental monitoring programs.

Dustin Bambic

Dustin Bambic

Dustin Bambic is a Director and professional hydrologist with Paradigm Environmental. He specializes in stormwater and watershed planning, including the international application of water quality modelling tools.

Dustin has undergraduate degrees in physics and mathematics, and graduate degrees in hydrologic science and environmental engineering from the University of California – Davis.