Commission debates changes to Resource Protection Overlay amid wildfire and insurance concerns

City planning staff told the Flagstaff Open Space Commission they are proposing a targeted recalibration of the Resource Protection Overlay (RPO) to better preserve high‑value trees and ridgelines while addressing wildfire risk and insurance market pressures.

Tiffany Antl said the RPO was largely drawn in the early 1990s and applied broadly (notably to vacant parcels larger than five acres). Under the current approach, residential parcels generally must preserve about 50% of forest resources, commercial about 30% and open space about 30%. Antl and staff proposed a pilot to change how forest resources are credited—moving from a simple DBH (diameter at breast height) point system toward metrics such as trees‑per‑acre and basal area per acre, using LiDAR data to identify and prioritize preservation of the largest, most resilient trees.

Commissioners pressed staff about the effect on wildfire risk and homeowners’ insurance. Antl said the city is coordinating measures including IBHS (Insurance Institute for Business & Home Safety) certification and potential code changes that would require a 5–10 foot clear area of noncombustible surface immediately around structures, prohibit new tree plantings close to homes (zone‑zero landscaping standards), and restrict wood fences that convey fire from house to house. Antl said she had received industry emails warning that insurers are reducing new policies and non‑renewing some existing policies, increasing homeowner concerns about market access to insurance.

Commissioners also raised maintenance and access concerns for RPO set‑asides that become common space; staff said multifamily projects are already required to set aside common space (often 15% of a site) and that the new planned‑community zoning option would require larger conservation set‑asides (20% of gross area) plus connectivity via foot‑trails. Staff acknowledged enforcement and long‑term maintenance are persistent challenges and that donations of open space to the city can create maintenance cost obligations for the city.

Antl emphasized the tradeoffs: preserving every small stand of trees on every lot can limit housing production and concentrate development elsewhere; the proposed approach aims to preserve meaningful corridors, ridgelines and high‑value habitat while allowing housing where the resource value is lower.

Next steps: staff will further refine the RPO calibration, test the LiDAR model on parcels and present draft code language for additional public input and eventual hearings.