Littleton planning commission reviews proposed tree manual and $250-per-inch mitigation fee

At a July 14 study session, Littleton City staff presented a proposed tree manual and related amendments to the Unified Land Use Code (ULUC) that would consolidate greenscape and tree provisions into a single technical manual and move arborist licensing into Title 3, Chapter 16.

The proposal, presented by Senior Assistant City Attorney Atassi Toto, would repeal and reenact Title 8 Chapter 4 (the city’s tree code), migrate planting species lists and technical planting/ protection standards into a draft tree manual developed with consultant Davey Resource Group, and update the mitigation fee structure. "The new proposed rate is going to be $250 per inch," Toto told the Planning Commission, adding that the staff recommends a reduced rate of $75 per inch for qualifying affordable housing developments and an exemption for property owners who can show verified financial assistance.

Why it matters: The changes would shift many technical rules out of the ULUC into a director-managed manual, affect how developers and homeowners comply with planting, protection and mitigation rules, and change how the city funds canopy work through its tree fund. Commissioners raised concerns about scale, enforcement, and impacts on small developers and downtown sites.

Staff and consultant work, scope and mechanics

City staff said the work began after a 2023 consultant review of Title 8, Chapter 4 and a draft tree manual. The consultant recommended modernizing terminology, clarifying permitting and licensing, and producing a tree manual with diagrams and species guidance. Staff proposes migrating redundant provisions from ULUC Article 10-1-3.6 (greenscape) and from Title 8, Chapter 4 into the tree manual, consolidating arborist licensing into Title 3, Chapter 16 (contractor licensing and registration), and formally adopting the manual via repeal/reenact of Title 8 Chapter 4.

The proposed tree manual would capture: approved and prohibited species lists (Table A-1 moved out of the ULUC appendices), planting requirements and an establishment period with specific dates, irrigation and warranty guidance, tree protection-zone standards and graphics, mitigation standards (including a fee-in-lieu), and technical location rules such as sight-triangle and right-of-way spacing. Staff said the tree manual is intended as a living technical document maintained by the director and (when hired) a city forester but that substantive changes (for example scale triggers) would be taken back to City Council.

Key numeric proposals and safeguards

- Fee in lieu: Staff proposed a mitigation fee of $250 per inch of replaced trunk diameter when on-site replacement is impractical; the proposal includes a reduced rate of $75 per inch for affordable housing projects and a carve-out for owners who can document verified financial assistance. The fee would flow to the city’s tree fund to support canopy work, including treating ash trees and targeted plantings in areas of low canopy.

- Establishment guarantee: Where plantings fail to establish, staff said the code would allow the city to require a financial guarantee equal to 125% of estimated costs until establishment, maintenance and inspections are complete.

- Species and standards: Planting species lists and substitution rules would move from ULUC appendices into the tree manual. Protection, preservation and canopy-percentage calculations are being reconciled between the draft manual and Title 8 Chapter 4; proposed increases to canopy-percentage requirements were discussed but the exact new percentages were not provided during the session.

Licensing and jurisdictional notes

Arborist licensing currently referenced in Title 8 (8-4-3 in the current code) would be migrated into Title 3, Chapter 16, which governs contractor licensing and associated bonding, insurance and indemnification. Staff said the tree manual and Title 8 provisions will continue to reference right-of-way and public-works responsibilities where applicable; public-works staff will continue to review technical Right-of-Way items.

Commission discussion and concerns

Commissioners pressed staff on several themes: (1) scope and triggers — whether requirements should apply to single-family, missing-middle, small commercial or only larger-scale and multi-family developments; (2) downtown and commercial fit — whether high canopy percentages make sense for narrow Main Street parcels or dense commercial blocks; (3) enforcement and staffing — whether the city has capacity to inspect and enforce new rules; (4) equity and the locus of cost — whether canopy goals should be paid by developers, the city budget or some combination; and (5) public process — several commissioners asked for broader public review before final adoption.

Staff responded that the tree manual was drafted as a technical guidance document to be adopted by ordinance and maintained by the director, and that some items (for example scaling or changing applicability thresholds) were not part of the consultant’s scope and would require additional discussion and likely a longer timeline. The presenter said staff would keep currently applicable ULUC greenscape provisions intact for now, move forward with revising the mitigation formula, and step back on canopy-percentage increases to give the commission and council more time to consider scaling and public input.

No formal vote or ordinance adoption occurred at the July 14 study session. Staff outlined a tentative schedule: commissioners’ recommendation targeted for July 28 (with potential bump to August 11), first readings of related ordinances in early August (August 9 cited), and City Council adoption of the repeal/reenact of Title 8 Chapter 4 and formal adoption of the tree manual at a later August council meeting. Staff told commissioners it will return with refined materials, additional justification for canopy percentages and comparative research from surrounding jurisdictions, and options for scaling applicability.

Next steps

Staff said they will: provide comparative analyses used to justify canopy-percentage changes; finalize the draft tree manual with public-works input; advance a change to the mitigation formula so the LEHI references point to enacted code; and return to the Planning Commission with options on scaling (by zone, parcel size, or unit thresholds) and a plan for public comment. The commission requested clearer documentation of the canopy‑percentage rationale and suggested staff ask City Council whether council wants additional public outreach before adoption.

(Article compiled from the Littleton City Planning Commission study session on July 14, 2025.)