At a Tuesday meeting, Cary Town Council began a discussion on how the town might transition from paying stormwater costs out of the general fund to a dedicated utility fee. While no vote was taken and no specific rates were set, the conversation laid out several possible billing structures.
Why a new fee matters
Stormwater that does not evaporate becomes runoff, traveling across lawns, driveways and rooftops into storm drains that feed local streams. Unlike many municipalities that combine stormwater and wastewater in a single sewer system, Cary already separates the two, protecting water quality but still relying on the general fund to cover stormwater expenses.
Flat‑rate versus ERU
Corvias Infrastructure Solutions (CIS), which manages stormwater programs nationwide, presented several funding scenarios using data from more than 52,000 billable parcels in Cary’s GIS system. CIS Managing Director Sri Vedachalam explained that a flat‑rate fee treats every property the same, meaning a modest townhouse could pay the same amount as a large Amazon warehouse.
Mayor Harold Weinbrecht noted that the current general‑fund approach essentially functions as a flat‑rate system. “When residents read a report that we’re going to charge more money, they go up in arms, but we’re actually changing how we’re going to bill you for what we’re charging,” he said.
What is an Equivalent Residential Unit (ERU)?
Vedachalam suggested that Cary is a strong candidate for an ERU model. An ERU represents the average impervious surface area of a typical single‑family home in a given area. Impervious surfaces—driveways, tennis courts, rooftops—prevent rain from soaking into the ground, increasing runoff and flood risk.
For example, if one ERU equals 3,000 square feet, a property with 6,000 square feet of impervious surface would be assessed two ERUs. Council member Michelle Craig said the model could save owners of smaller homes: “For an individual like me who lives in a smaller home on a lot with far less impervious surface, I would actually be saving money under the ERU model, compared to someone with a very large home.”
Fairness for multi‑family dwellings
Craig also addressed concerns about vertically stacked apartments. Under an ERU or hybrid ERU system, a two‑ or three‑story building with 3,000 square feet of living space would likely have a smaller impervious footprint than a single‑story ranch home of the same square footage, meaning owners would not be charged disproportionately.
The ERU approach does require more upfront calculations, but Cary’s robust GIS resources provide the necessary data to compute each parcel’s impervious area accurately.
Next steps
The council’s discussion was conceptual, and no formal decision was made. The UNC School of Government shared a stormwater utility fee dashboard to help residents visualize potential outcomes. Council members indicated that further analysis and public input will shape any future fee structure.
As Cary continues to grow, officials emphasized the importance of a billing system that reflects actual stormwater impact while protecting homeowners from unfair charges.
Original reporting: WRAL Raleigh — read the source article.
