Development of a stormwater credits program at Halifax Water

Abstract

This paper examines stormwater credits as a specific area in the development of a stormwater utility. Halifax Water, as a public utility, is in the process of developing a rate structure for stormwater to provide dedicated funding for this component of its infrastructure. The principles by which utilities are guided allow for customers to opt out of receiving the service. Stormwater Credits are designed to reduce stormwater charges for customers who store stormwater on their property and thereby reduce the utility’s costs. To assist Halifax Water in establishing a stormwater credits program, this study has three objectives. The first is to determine current practices with respect to stormwater credits in a sample of ten other cities in North America and recommend approaches that may be appropriate for consideration by Halifax Water. The second is to prepare a sample flow diagram for a credit application approval process. The third is to conduct cost analyses to determine Halifax Water’s cost of administering a credit system and the economic feasibility for property owners to manage their own stormwater using a payback analysis for a typical commercial and residential Stormwater Management Practice (SMP) storage options. The study found that the most fair and equitable basis for credits and credit amounts may be a ‘sliding scale’ approach based on a percentage of area diverted from the stormwater system via approved SMPs. Another key finding is that while removing barriers to entry and working in other ways to improve the feasibility of SMP ownership may increase participation rates, it is likely that Halifax Water’s cost of stormwater service will not be offset by reduced runoff until such time as water quality is regulated in Nova Scotia and is factored into the cost equation.