Water Distribution System Rehabilitation under Climate Change Mitigation Scenarios in Canada

Abstract

Many countries are considering policy instruments such as a carbon tax and economic discounting to reduce greenhouse gas (GHG) emissions in key sectors like the water sector. This paper examines the impact of economic discounting and a carbon tax on the optimization of water main rehabilitation. A new pipe rehabilitation optimization algorithm that accounts for GHGs was developed and applied to the Fairfield water distribution system in Amherstview, Ontario, Canada. GHG intensity factors for the provinces of Ontario (low-carbon) and Alberta (high-carbon) were applied to the Fairfield network. In both cases, adopting a low discount rate and levying a carbon tax had a weak effect in reducing energy use, GHG emissions, pipe breaks, and leakage. Further, a low discount rate and a carbon tax encouraged the search process to invest in rehabilitation early in the planning period to reduce continuing leakage, pipe repair, energy, and GHG costs.