Proposed Sandhill Major Subdivision Violates Law and Threatens Clean Water Resources

Gallatin County Commission Should Deny Application

On Tuesday, April 25th, the Gallatin County Planning Board rubber-stamped a preliminary plat application for the Sandhill Major Subdivision, a new 34-lot subdivision south of Bozeman city limits reliant on exempt wells and septic systems. Upper Missouri Waterkeeper submitted comments to the Planning Board opposing the proposed subdivision.

“Thirty-four trophy homes doing the bare minimum to mitigate environmental impacts is not the type of development this community needs. In fact, this is the exact type of development that should, and can, afford to pay it forward to ensure responsible growth doesn’t sacrifice our clean water resources,” said Guy Alsentzer, Executive Director of Upper Missouri Waterkeeper. “It’s time for our County Commissioners to put their collective feet down and stop rubber-stamping development that fails to address our communities’ needs while degrading and exploiting our local water resources.”

The project in question, the Sandhill Major Subdivision, is proposed just south of Kagy Rd and east of the Painted Hills subdivision. The development proposes to use a system of clustered exempt wells, cutting corners in the water rights permitting process and avoiding required water impacts and availability analyses. The clustered wells’ combined withdrawals will exceed several times over the 10/ac/ft/yr limit on any new subdivision, violating the Montana Water Use Act, the Department of Natural Resources and Conservation’s combined appropriations rule, and Montana Supreme Court precedent in Clark Fork Coalition v. DNRC.

The development also proposes the use of septic systems, which are known contributors of water degradation throughout Gallatin County, and particularly in the Gallatin Valley. Despite this, the preliminary plat application failed to examine the potential cumulative impacts of septic wastewater on downgradient private wells and water resources, and likewise avoided considering potential impacts of new septics on the adjacent headwaters tributary of Rocky Creek, located just southeast of the proposed Subdivision’s septic drainfields. 

The Gallatin County Senior Planner provided comments on the Sandhill Major Subdivision highlighting similar water concerns as Waterkeeper. County Staff agreed that the clustered wells should be limited to 10-ac/ft/yr to protect senior water rights, and suggested the developer provide additional information on how the proposed plan to provide water for the subdivision is in compliance with the Montana Supreme Court decision of Clark Fork Coalition v. DNRC

Without the proper and legally-required analyses of impacts to water quantity and quality, the Commission has no scientific basis for approving the application as-proposed. In Fall 2022 the Gallatin County Commission considered a similar major subdivision proposal, Hyalite Creek Major Subdivision, which also involved “clustered” exempt wells and new septic systems nearby Hyalite Creek. The Commission denied the Hyalite Creek major subdivision application because of inadequate review and not being a good fit with planning mandates.

The Commission is hosting a public hearing on Tuesday, May 9th at 9am to approve or deny the preliminary plat for the Sandhill major subdivision.