Engineers tell Rathdrum council summer demand is straining wells; recommend new wells and 1'2M-gallon tanks

John Bownie, project presenter for JV Engineers, told the Rathdrum City Council the water-system master plan is "more than just a report" and that consultants have converted paper record drawings into a usable GIS and built a near-calibrated hydraulic model to inform capital planning.

The presentation described the project's scope: mapping the system, ingesting five years of meter and operational data, and developing a hydraulic model calibrated to average-day and peak conditions. "We have a near calibrated model," Bownie said, and engineers plan a 72-hour simulation to show pressure and tank-level fluctuations throughout a day.

Why it matters: Bownie said the community's customer counts have risen sharply since 2020 and that summer irrigation creates a large peak; he told council "seven times the amount of water" can be used in summer compared with winter baseline demand. That combination, he said, is stressing wells and northern tank recovery during morning peak hours and has produced isolated low-pressure areas in the Brookshire neighborhood.

Preliminary recommendations are focused. Bownie said the near-term plan will likely combine additional supply (new wells sized to match existing large-capacity wells) and additional storage (nominal tank options discussed at about 1'2 million gallons, or multiple tanks). "Additional supply and storage infrastructure is necessary for both the near term and future conditions," he said, adding that tank siting and backbone looping to interconnect wells and tanks will be key to delivering water where it's needed.

Council members asked about schedule and accuracy. Bownie said the team expects near-term calibration deliverables and tech memos to be released by the end of September, with final future-condition findings wrapped into the master plan by year-end. He described model accuracy targets of roughly plus-or-minus 5'10% for pressure calibration and said the model will be adjusted if calibration falls short. The firm told council it can request additional field data or targeted fire-flow testing if necessary to close gaps in calibration.

What's next: engineers will publish tech memos to support budgeting for the next fiscal year and will provide specific well- and tank-sizing recommendations once calibration is complete. Staff and consultants said they will use the model to test scenarios and present recommended capital projects for council consideration.

Public comment and council discussion at the meeting did not amend the study; the presentation was informational and will feed staff's upcoming budget recommendations.