Ivins hears sewer master plan, faces $621 impact-fee proposal and multimillion-dollar upgrades

Consultants for Ivins City presented a draft Sewer Master Plan and an impact-fee analysis to the City Council on May 1, laying out projected system needs, costs and a proposed sewer impact fee of $621.55 per equivalent residential unit (ERU) that would apply to new development. Aaron Anderson of Bowen Collins & Associates told the council the study is near final but still subject to review with Santa Clara City and city staff.

The presentation summarized how the plan converts current and future demand to ERUs and uses hydraulic modeling to identify capacity shortfalls. "We've been working on this master plan for a while now," Anderson said, and the draft shows no immediate system deficiencies but predicts several pieces of collection piping—and a lift station and force main along Old Highway 91—will be needed as the city grows. The draft estimates Ivins’ current system at 4,628 ERUs, with a long-term buildout of about 11,551 ERUs.

Why it matters: the plan identifies near-term projects the city would likely fund and partially recover through impact fees charged to new development. Anderson said the ten-year capital program for collection-system projects is just under $7 million, with the largest single project being a Lower Tuocon Wash line replacement and upsizing (a joint project with Santa Clara). Rehabilitating or replacing all existing sanitary infrastructure today would cost the city an estimated just-over $100 million, the consultant said; based on that valuation the report recommends an annual rehabilitation-and-replacement (R&R) budget in the $450,000–$900,000 range.

Key technical assumptions: the study uses 59 gallons per day as the domestic average sewage contribution per ERU, an infiltration allowance of 16 gpd per ERU, and an average design flow of about 175 gpd per ERU. Forecasting uses a 10-year planning window for impact-fee eligibility; the model flags several collection segments approaching capacity in the 10-year horizon and additional segments by 2050 buildout.

Impact-fee calculation and proposed fee: Anderson and Chuck (city staff) explained the impact-fee math: a buy‑in component for existing capacity plus the proportionate share of new facilities apportioned to the ten‑year growth forecast. Based on the draft capital plan, asset valuation, and assumed financing, the draft collection-system impact fee comes to $621.55 per ERU (this number excludes any collection/treatment charges paid to St. George City). The consultants noted this is about $70 higher than the prior adopted figure; the increase reflects updated project lists and bond-interest assumptions (the draft assumes a $2 million bond at 4% interest, 3% issuance costs over 20 years, producing roughly $1 million in interest under those assumptions).

Cost splitting and coordination: the Lower Tuocon Wash project would be shared with Santa Clara. The draft draft cost-share split for affected capacity was presented as roughly 75% Ivins / 20% Santa Clara / 5% other, subject to final engineering review and negotiation with Santa Clara’s engineer.

Next steps and council direction: Anderson said the team will finalize the master plan documents and return with a rate analysis and the impact-fee report for council review; staff expects draft reports to be available the following week and signaled a later public-hearing step before adoption. Council members discussed the proposed R&R reserve range, where some members favored the lower end to avoid building a large unused fund and others favored a more conservative approach. No formal vote on adoption or fees occurred at the meeting; staff was directed to bring the finalized reports and a recommended rate/fee schedule back to council for further review and for scheduling a public hearing.

Context and limitations: the presentation covers collection-system needs only; Ivins does not operate a treatment plant and some fees and treatment costs will continue to be paid to regional providers. Several figures in the presentation are planning estimates (e.g., long‑term buildout of 11,551 ERUs, and 3,000 ERUs anticipated in the next 10 years) and Anderson noted the numbers will change as zoning or development assumptions are updated.

Ending: City staff and consultants said they expect to return with final reports, a recommended fee schedule and a draft rate analysis for council review before any public hearing or vote on impact-fee adoption. Council members asked staff to come back prepared to discuss a preferred R&R funding level so the rate analysis can reflect council priorities.