Consultant outlines six rate scenarios, warns persistent inflow-and-infiltration would raise wastewater costs

At a July 17 Rowlett work session consultant Jason Gray walked council through six scenarios for FY27 and multi-year utility-rate planning, explaining the assumptions and the fiscal consequences.

Gray said scenario 3 was used as a baseline designed to maintain a 1.14 debt-service-coverage ratio; "Scenario 4 then, assumes that the inflow and infiltration problem persists," he said, adding that scenario 5 removes a planned $7,000,000 debt issuance from the FY27 model and that change primarily affects FY28 and later. He described scenario 6 as a baseline-plus approach that increases monthly wastewater base charges by meter-size equivalency.

Gray told the council that scenario 1 (worst-case) would increase an average residential bill from about $1.42 to roughly $1.63 in FY27 (about a $21 increase), while the main differences across scenarios become more pronounced in FY28 and FY29 if I&I is not resolved. He stressed the scenarios were designed to isolate single variables so the council could see the budget and rate impact of each assumption.

Council members requested additional modeling that reflects ongoing CIP work to address I&I and asked staff for updated data to show whether the I&I measures being implemented reduce projected costs. Staff said some pipe replacements have already occurred and that odor-control calibration work is underway.