Northampton commission debates tougher tree protections, seeks centralized tracking and LiDAR baseline

The Northampton Urban Forestry Commission discussed proposed changes to a draft Significant Tree Ordinance at its Oct. 6, 2024 meeting, with public comment urging stronger protections and commissioners debating how stricter rules could affect compact development.

Public commenter Kent asked the commission to “make it even stronger,” urging lower diameter-at-breast-height (DBH) thresholds for the Central Business and urban residential zones, tighter limits on planning-board exceptions, larger replacement requirements for very large trees and a requirement to keep records for individual projects as well as annual totals. Kent said he had emailed detailed suggestions to commissioners.

The commission’s chair said the draft has evolved through multiple conversations with the Office of Planning and Sustainability and that blue text in the circulated PDF shows earlier commission edits. The chair explained the more recent staff changes raised the DBH thresholds for URC/URB/URA zones and noted the ordinance currently applies only to trees on private property when a project requires site plan approval, a special permit or zoning relief from the planning board; public‑right‑of‑way trees remain governed by MGL c. 87. “This ordinance is only for private for projects that are under site plan approval, special permit, or zoning relief from the planning board,” the chair said.

Commissioners spent much of the discussion on the table of DBH thresholds and replacement ratios. One commissioner recalled that earlier negotiations with planning staff had raised some DBH values and changed replacement rules (for example, moving toward a 1‑inch replacement for each inch removed in some categories). Several commissioners said they supported reducing DBH cutoffs in downtown zones because urban trees there are especially valuable; others noted planning staff’s concern that stricter thresholds could discourage higher‑density, nearly net‑zero development in downtown and gateway areas.

Commissioners and the chair also discussed tools for measuring and tracking the city’s canopy. The chair said the state’s LiDAR flown in spring provides a data layer the city can analyze as a baseline, and that building‑department permitting has been updated with dropdown fields to capture the number of trees removed and their DBH at the time a permit is pulled. That change, commissioners said, should make it easier to centralize project‑level records. "The information is in the plans, but it's very difficult to find," Kent said; commissioners proposed a single public spreadsheet or dashboard containing approval date, project address, applicant name, trees removed, total DBH removed, replacement trees and their DBH, and mitigation fund payments.

Some commissioners questioned how many private trees would meet the proposed DBH thresholds in the URC/URB/URA zones. The chair said private‑property DBH values are generally unknown until a project is submitted, but LiDAR might provide estimates to inform policy choices.

Commissioners also discussed practical next steps. The chair described the process for moving a commission recommendation forward: the commission’s changes would go to the mayor; the mayor would decide whether to submit the amendments to the city council; the council would refer the matter to committee and likely hold a joint public hearing with the planning board before any council vote.

The commission took no final vote on the ordinance at the meeting. It recorded and approved minutes of a prior meeting and identified follow‑up tasks, including further review of the STO draft, work on centralizing recordkeeping and additional analysis of LiDAR data to better estimate canopy and tree DBH distribution on private property.