Zephyrhills consultant outlines $118-per-ERU stormwater utility and credit options; council to consider ordinances this summer

Zephyrhills officials heard a detailed presentation May 11 on a proposed stormwater utility that the city’s consultant said could provide dedicated funding for regulatory compliance, operations and capital projects.

"A stormwater utility is an enterprise fund that provides stable, dedicated, and equitable funding," Christina Conchilla, manager with Raftelis’ stormwater management consulting division, told the council. She said the study uses impervious area as the billing basis — the industry standard — and that the preliminary calculation yields a rate of $118 per equivalent residential unit (ERU) per year.

Conchilla described the proposed billing approach: single-family residential would be charged a flat rate of one ERU; multifamily and nonresidential properties would be billed based on measured impervious area divided by an ERU of 2,770 square feet; parcels with less than 400 square feet of impervious area would not be billed. She said tax-exempt properties (federal, state, school) are generally exempt under Florida law but noted the city can elect to bill municipal parcels to lower per-unit charges for residents.

On credits, the draft policy includes two tiers: a 50% credit for systems that meet post‑October‑2025 design standards (or the city's higher design standard) and a 25% credit for systems meeting earlier design standards; credits would be valid for five years with reapplication and documentation of maintenance.

Council members asked whether single‑family residents should be eligible for credits if they maintain private treatment systems; Conchilla said the flat single‑family approach normally precludes individual credits, but the policy can be amended to allow HOA or subdivision-wide applications. She also said the consultant will run example cases (large, medium, small business users) at council request.

Revenue and timing: the consultant estimated total annual revenue needs at roughly $2.5 million (variable by the capital projects selected) and said a non‑ad valorem assessment billed through Pasco County’s tax roll would be collected beginning in November if adopted on the schedule proposed. That timeline requires finalizing rates and credits, holding first and second ordinance readings, and certifying the assessment roll by Sept. 15 for inclusion on the November tax bill.

Public works and finance staff said some capital projects in a 5–10 year program and two additional public‑works crew members were included in the revenue need. Council members asked to phase implementation and to see model bills for representative properties before finalizing the rate and credit policy.

Next steps: staff and Raftelis will revise the credit policy and provide sample customer bills and the final rate for council consideration at the first and second ordinance readings this summer.