The Town of Concord task force on Tuesday reviewed a revised budget for proposed dam removal that preserves the Sumco removal subtotal of $1,100,000 and introduces a clear lower and upper range for stream-channel establishment.

The task force’s co-chair Jeff (task force co-chair) said the Sumco number of $1,100,000 remains the consistent subtotal from a previous proposal. He added the group is presenting two channel-length scenarios — roughly 1,000 feet and 2,000 feet of engineered channel — and is showing cost estimates for both.

Why it matters: the additional channel work shifts the project from a simple dam removal toward a combined removal-plus-channel-establishment approach. That increases upfront capital costs but, the task force said, better meets the stated project objectives for access and predictable flow paths.

Under the revised spreadsheet discussed on screen, the task force presented channel-establishment line items of $365,000 and $300,000 for the lower-range (1,000-foot) scenario; the draft doubles those figures for the 2,000-foot scenario to $730,000 and $600,000. The larger numbers reflect construction access (for example, biodegradable wood-wetland mats) and channel-formation work drawn from earlier vendor estimates and reference projects.

Jeff said those per-foot reference values came from prior cost proposals and that the group instructed staff to ask EA Engineering (the project engineer) what additional surveying, data collection and percent-design tasks would be required to produce a design that locates the channel where the task force wants it to be. He said the task force would not pay for additional design until the town decides to proceed with the removal.

Members emphasized the project assumes a degree of engineered intervention — not concrete channelization but logs, biodegradable core mats and other low-impact measures — to “influence” the path of the new stream rather than leave the route entirely to chance. As Jeff put it, the interventions are intended to “influence the path the channel takes and not steel and concrete.”

The task force kept a single recurring expense line for adaptive management and calculated a five-year total for those ongoing monitoring and maintenance activities. Task force members agreed the five-year horizon is conservative and that adaptive management could continue beyond that period if needed.

Key technical details discussed: the total channel length through the impoundment area was discussed at roughly 3,750 feet (3,750 ft), with a southeastern constriction where the system narrows to about 1,000 feet; the deep-pool and passage areas between the deep hole and Mesoba Brook are roughly 500–1,000 feet. An EA Engineering hydrology summary and bathymetry informed those estimates.

Sediment handling and reuse also factored into the budgeting discussion. One member noted a comparison project in Framingham where sediment recovered during channel work was reused on site for channel stabilization rather than carted offsite.

Votes at a glance
- Motion: Approval of the January 9 meeting minutes. Motion text in the transcript: "I move we approve." (mover not specified; second: Sammy). Vote recorded: "Aye." Outcome: approved.

What’s next: staff (Jeff and project contacts) will request from EA Engineering a clearer statement of the additional percent-design scope and associated costs to show what would be required to produce an engineered channel for the lower and upper scenarios. The task force asked staff to preserve both the lower- and upper-range columns in the budget to support public discussion and comment.

Ending: Task force members said they will present the revised budget, ranges and conceptual channel graphics at an upcoming public presentation and refine numbers if reviewers request reduced engineering or alternative sediment-handling approaches.