Baxter staff: well rehabs raised output but well field remains below design; council asked to authorize pump quotes and future wells

City of Baxter staff told the council that recent well rehabilitations improved output but the city’s four-well field still produces less than the system’s original design capacity, and recommended replacing pumps in Wells 1 and 4, drilling two additional production wells, and operating more wells at lower rates to reduce drawdown.

The recommendations came during two linked presentations: an update on well performance and a hydraulic-model briefing by Chad Katzberger, a senior engineer with SGH. “I’m Chad Katzberger. I work with — I’m a senior engineer with SGH, and I specialize in water system planning and modeling,” Katzberger said while reviewing the city’s updated distribution model and demand projections.

City staff summarized 2023–24 well testing and rehabilitation work and the resulting capacity changes. Before the 2023 high-demand period, the well field’s total capacity was about 4,000,000 gallons per day (MGD) and the firm capacity (the amount available with the largest pump offline) matched the 2013 design flow at roughly 2.9 MGD. After rehabs completed in 2024, maximum daily output from all wells fell to about 3.3 MGD, and firm capacity dropped to about 2.4 MGD — roughly 600,000 gallons per day less than the earlier firm capacity and 700,000 gpd less than the design capacity.

Staff explained that specific capacity (gallons per minute per foot of drawdown) had declined during 2023 and partially rebounded after rehab work. The consultant noted variability by well: Well 3 pumped more than 600 gallons per minute (gpm) after rehab while Wells 1, 2 and 4 produced between about 500 and 600 gpm. One well showed only a 6% specific-capacity increase from rehabilitation while another gained about 53% from a lower starting point. Staff cautioned that repeated rehabilitation typically yields diminishing returns as wells age.

Staff also gave cost and operating details: average rehabilitation cost this year was about $32,000 per well (contractor cost, excluding engineering fees), and staff estimated replacement pumps would cost “a little less than $20,000 per pump” with an installation lead time of roughly five to six weeks after ordering.

To reduce drawdown and improve pumping efficiency, staff recommended operating more wells at lower individual pumping rates rather than running fewer wells at higher speeds. As an example, producing about 2.0 MGD (roughly 1,400 gpm) could be achieved by running three wells at approximately 465 gpm each rather than two wells at 700 gpm. Staff also recommended replacing pumps for Wells 1 and 4 to restore the ability to produce about 700 gpm from those wells and advised drilling two additional production wells sited farther from the existing four to reduce interference; the two proposed new wells would be spaced roughly 500 feet apart from one another and from the existing wells.

Staff described interconnect constraints and wholesale purchase costs: the minimum flow through the Brainerd interconnect is 300 gpm, and purchasing that flow all summer at Brainerd’s current commercial rate would cost more than $27,000 extra compared with selling that amount of water at Baxter’s current customer rates, staff said.

Katzberger’s hydraulic-model presentation supported the operational recommendations and identified distribution priorities. The modelers updated a digital hydraulic model (originally built in the early 2000s), calibrated it with field pressure and flow data, and used it to test scenarios including removal and relocation of a segment affected by the planned Highway 210/371 interchange. The modeling indicated only a short pipe segment would need to be reinstalled to maintain system reliability if that transmission main were removed for the interchange work.

The model also highlighted local distribution issues: the far west side of the city remains deficient in available fire-flow capacity because of limited looping in that area. Katzberger said that a future elevated storage tank on the west side would likely be the most effective way to increase fire-flow availability there and that a targeted trunk-main upgrade north of Whiter Road could nearly double available fire flow in some areas.

Staff laid out a trigger chart for future investments: installing two new wells (wells 5 and 6 in staff materials) would raise capacity above projected maximum-day demand for several years; staff’s planning map shows a possible seventh well being needed in the early 2030s if growth follows projections. The model also helped staff prioritize looped mains and storage additions relative to expected development.

Council members asked about conservation measures and rate structures. Staff and the consultant noted that outdoor irrigation typically drives summer peaks; examples from peer utilities showed mixed results for odd/even watering restrictions and for stepped “conservation” rate tiers. Staff cautioned that some enforcement schemes require ongoing staffing to be effective, and that development (new apartments, car washes and commercial landscaping) also increases year-round average demand.

No formal vote on pump replacements or well drilling occurred during the discussion. Staff said they would seek council direction to request quotes for pumps for Wells 1 and 4 and planned to ask the council in the coming weeks for authorization to advertise for two new production wells. Katzberger’s hydraulic model report is listed on a forthcoming regular meeting consent agenda for acceptance so staff can close the consulting contract and use the model for ongoing planning.

Quotes in this story come from the meeting transcript and staff presentations: city staff recommended “replace pumps for wells 1 and 4 to achieve up to 700 gallons per minute per well” and Katzberger introduced the modeling work by saying, “I’m Chad Katzberger. I work with — I’m a senior engineer with SGH, and I specialize in water system planning and modeling.”

Next steps: council members will consider staff requests to seek quotes for pump replacements and will see the hydraulic model report on the regular consent agenda; staff will return with cost proposals and bids for council action.