Portsmouth Evaluates Stormwater Funding Options

Portsmouth, New Hampshire – The City has contracted with Raftelis Financial Consultants, Inc. to assist in evaluating whether it should create a dedicated Stormwater Enterprise Utility. The Raftelis team presented an introduction to the topic at the Monday, September 28, 2026 City Council meeting. They outlined a process centered on developing fair funding and equitable solutions for sustainable management of the City’s stormwater infrastructure.

The City currently pays for its stormwater system through an equal split between the General Fund and Sewer Funds. As the City completes more of its sewer separation projects, a greater share of stormwater program costs will shift to the General Fund. The current structure does not align costs with impact. Single-family homes represent roughly 70% of the City's properties but account for only about 15% of the paved and hard surfaces that produce runoff. As a result, homeowners pay a disproportionate share of stormwater costs through property taxes.

A dedicated Stormwater Enterprise Utility would change that. Property owners would pay a fee based on the amount of impervious surface on their land, such as roofs, driveways, and pavement. These surfaces prevent water from soaking into the ground and increase runoff, so this approach would distribute costs more equitably while providing a sustainable, dedicated revenue source for infrastructure maintenance and regulatory compliance.

Raftelis will provide the City Council and the public with data, rate models, and policy analysis needed to decide whether to create a Stormwater Enterprise Utility. The work will begin with City staff and Raftelis jointly reviewing feasibility data and planned infrastructure upgrades. The team will then update financial models to establish program revenue requirements and develop several rate structure alternatives designed to distribute stormwater costs more fairly. City staff and Raftelis will also design policies for fee credits and incentives.

“A Stormwater Enterprise Utility would allow us to fund needed infrastructure improvements more equitably by linking fees to how much impact each property has on the stormwater system. Using GIS data and careful evaluation of program costs and future infrastructure demands, we're working to develop a sustainable approach that protects residents and the environment, supports regulatory compliance, and ensures long-term investment in the City's stormwater system,” said James McCarty, Operations Manager, GIS & Stormwater.

Before the City Council makes any decision, the Raftelis team will support public outreach efforts through interviews with community stakeholders and an online survey to gauge how familiar residents are with the issue. The findings will guide the City’s public information plan, which may include explainer videos, fact sheets, and community open houses. Raftelis will also work with City Information Technology (IT) and Geographic Information Systems (GIS) staff to build a public web application. Property owners will be able to view their impervious surface area, calculate fee estimates, and access online appeals and abatement processes.

This work is funded through existing stormwater funds. The team will work closely with City legal staff to draft a comprehensive utility ordinance, credit policies, and fee resolutions that ensure compliance with New Hampshire law.

About Raftelis
Raftelis is part of a national water, wastewater, and stormwater consulting practice and has a dedicated stormwater team of more than 20 specialists. The firm has helped implement more than 75 stormwater utilities nationwide, in numerous similarly sized communities to Portsmouth as well as the Boston Water and Sewer Commission.

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