Boulder County HPAB approves Longmont’s proposed 6.4M‑gallon tank at Montgomery Farm amid tribal and neighbor concerns

The Historic Preservation Advisory Board voted 6–3 on May 1 to approve a Certificate of Appropriateness allowing the City of Longmont to construct a partially buried 6,400,000‑gallon finished water tank on the landmarked Montgomery Farm at 5435 Ute Highway.

The tank, which Longmont says is needed to replace an aging storage facility and to increase emergency and routine storage for Longmont, Hygiene and Lyons, would sit in the northwest corner of the Montgomery Farm parcel. Boulder County staff told the board the county’s review today was limited to the landmark certificate criteria; a separate Areas and Activities of State Interest (1041) review by the county and county commissioners will address a broader set of land‑use issues.

Why it matters: the Montgomery Farm is a designated Boulder County landmark that includes seven contributing structures. Neighbors and tribal community members told the board the northwest location places the new tank closer to historic resources, ceremony sites and nearby homes. County staff and the city said the site was selected after a multi‑factor alternatives analysis and that design measures (partial burial, muted concrete color, screening plantings and dark‑sky lighting) will reduce visual impacts.

Longmont project manager Joe Michalski told the board the existing tank is at the end of its serviceable life and the replacement would increase system resiliency and emergency capacity. “This project would replace critical distribution system infrastructure, would promote public health and safety, improve the city’s system resiliency and security, and increase effective water storage capacity,” Michalski said. The city’s presentation described a six‑alternative evaluation; the preferred site scored highest on proximity to existing tie‑ins, minimized ground disturbance and lower overall public cost compared with other options.

The city’s design team and county staff walked the board through the proposed footprint and mitigation measures. Engineering staff said the new concrete tank would be partially buried, with an above‑grade dome that is about 27 feet at the peak and sides roughly 10 feet above grade; roughly 15 feet of the tank would be below grade with piles extending about 20 feet. The design includes a new redundant 48‑inch finished water pipeline, a sampling building, a gravel access road with an asphalt apron, an eight‑foot security fence, a stormwater management basin, and restored open space where the existing tank will be removed.

County staff recommended approval only after confirmation from the subcommittee that additional screening, a darker finish on the new tank and county review of final vegetation, post‑construction reclamation and lighting plans would be available to mitigate impacts.

Neighbors and tribal commenters said the project threatens ceremonial use and the farm’s remaining agricultural context. Mary Dobbs, a neighbor who said she has lived adjacent to the farm for 33 years, told the board the project would “harm and desecrate the land many hold as historic and currently very sacred.” Kendra Berg, who identified herself as part of the local Native community, urged broader tribal consultation under federal statutes and executive orders and asked the county and city to acknowledge and protect ceremonial use areas.

City staff said Longmont has contacted 48 tribal offices identified by the Colorado Commission of Indian Affairs and has heard responses from three tribal entities; the city also described an inadvertent discovery plan that would be implemented if construction uncovers archaeological remains. The city said it will continue tribal outreach and that it has been responsive to adjacent property owners’ questions about location and construction timing.

Board members pressed the city on alternatives, setbacks from irrigation ditches, and the stormwater basin location. County staff noted some constraints: required ditch setbacks, existing pipelines and the proximity of distribution tie‑ins that increase disturbance and cost if the tank moves significantly farther from the existing pipeline network. The city estimated permanent loss of about a little more than an acre of land currently leased for hay cultivation on the Montgomery Farm; staff said much of the site’s remaining farmland will continue to be leased for haying and that the city would maintain contributing structures after construction.

Construction timing and scale: the city estimated construction of the new tank would take about 18 months, with demolition and site reclamation of the old tank extending project work toward two years in total; staff said construction could begin in the first or second quarter after county 1041 permitting and other approvals.

The board’s approval was not unanimous. Members voting yes cited the narrow scope of the certificate of appropriateness (preserving the physical integrity of the contributing structures) and the city’s mitigation plan; members voting no cited visual and cultural impacts and urged additional study and stronger commitments on tribal consultation and site configuration.

The approval does not eliminate additional county review. County staff said future 1041 review will examine broader impacts and that the county will circulate materials and accept public comment during that process. The city and county staff committed to keep interested parties notified and to continue tribal outreach and neighbor coordination as design proceeds.

What’s next: the city must complete detailed design and obtain the county’s 1041 decision and all applicable permits. County staff said they will continue to monitor city outreach and may return issues to this board for additional comment if new information arises during the 1041 process.