Bow Selectmen press for updated cost estimates and design options for northern water extension and Hooksett interconnection

Selectmen and staff spent the bulk of the April 8 meeting reviewing a multi‑year plan to extend Bow’s municipal water service north along Route 3A to Bow Mills and Bow Junction and to explore an interconnection with Hooksett’s water system.

The engineering team explained why the town is reconsidering the project’s scope and delivery approach as cost estimates have risen since the plan’s first feasibility work. Nick, a DuBois & King project engineer, told the board the original waterline estimate used when the TIF (tax increment financing) district was created had been about $4.3 million for the main extension, and that overall project totals now exceed earlier figures. “The existing Bow municipal water system is at capacity,” Nick said. “It was designed for a million gallons per day.” He said a combination of higher construction costs and the need for additional storage and pressure management has made the project more complex.

Why it matters: the northern water extension is tied to the Town’s economic development plan inside two TIF districts. The development program assumed new municipal water would unlock property development, capture new tax value inside the TIF, and help cover bond costs for infrastructure. As estimates have grown, Selectmen asked staff and engineers to re‑examine lower‑cost alternatives and funding scenarios before committing to a bond or asking voters to revise the TIF plan.

Key discussion points and options

- Storage versus pumping: Engineers described two technical approaches to providing adequate pressure at the higher elevations on Route 3A. The first is an elevated storage tank located near the highest point on the route (variously described in the briefing as the “golf cart property” and alternatives east of I‑93). The second is a booster (pumping) station sited closer to existing power and road access. Nick said the tank option provides reliable gravity pressure and improved fire flows for the area; a booster station would require continuous electrical power, an emergency generator and higher lifecycle maintenance costs. He characterized a booster building as a larger shed (roughly 24 by 20 feet), vs. a smaller interconnection building (about 12 by 12 feet) for the Hooksett connection.

- Costs discussed in the meeting (as presented by staff/engineers): the original water main estimate cited when the TIF plan was drafted was about $4.3 million; the most recently discussed elevated tank estimate was discussed in the meeting as roughly $3.3 million; past program totals mentioned in the briefing reached “over $12 million” for the north extension and, when combined with treatment upgrades referenced separately, about $15 million. Engineers and Selectmen each emphasized these numbers are estimates and that costs have risen since the initial studies.

- Concord loop and alternatives: staff reviewed an alternative routing called the “Concord Loop” that would connect to Concord’s system; the engineering team said that option at one point produced a lower cost estimate because it avoided a long run of water main down Route 3A. Design progress on the Concord alternative reached roughly 60–95% before negotiations with Concord stalled over interconnection terms; staff put that option on pause but retained the design files.

- Hooksett interconnection: Hooksett officials and the town’s engineer have discussed potential interconnection and sale of water. The Hooksett superintendent has indicated interest in revisiting intermunicipal water, and Hooksett’s water precinct participated in a DuBois & King feasibility study. Nick said the next step for a Hooksett interconnection is advancing feasibility drawings to 60% design (survey, alignment, utility conflict review) to refine cost estimates and define the interconnection structure (metered above‑ground building vs. a below‑grade vault). Selectmen asked the engineering team to provide a 30%/60% cost schedule for that work.

- Treatment and water quality: engineers noted the treatment plant will need upgrades to address iron/manganese and emerging contaminants (PFAS). That treatment work was discussed separately from the distribution extension and would add to future costs if the town chose to expand treatment capacity.

Board direction and next steps

Selectmen asked staff and DuBois & King to return with updated cost estimates and design proposals that explicitly compare the elevated tank option against one or more booster‑station alternatives, including a 30‑ and 60‑percent design cost schedule for each corridor (north extension and Hooksett interconnection). Staff identified grant opportunities and existing TIF constraints: improvement work charged to TIF funds must serve the district and follow the adopted development plan; bond language and voter approvals would still be required for debt financing. The board also asked for lifecycle cost comparisons (30‑year cost of ownership) to weigh capital savings against ongoing maintenance and utility operating costs.

What remains unresolved

Selectmen did not authorize a bond or choose a final alignment. The meeting produced direction to refine design and budget information so the board can discuss public outreach, potential voter questions, and timing for any bond or TIF plan amendment. Staff said they will provide updated scopes, cost estimates, and grant‑eligibility analysis at the board’s request.