ATTACHMENT G_Landscape Code Interviews Memo 7.7.25

Attachment G - Summary of Feedback from Peer Communities

Landscape Codes Update Research: Assessment of Relevant Examples from Other Jurisdictions July 7, 2025

Background

In June 2025, Lauren Freels and Caroline Petterson of the Climate Initiatives department nature-based solutions team conducted interviews with eight municipalities who have demonstrated leadership in water efficiency and/or climate resiliency in their landscape codes/ordinances. In some meetings they were joined by other city of staff, including Krystle Morey from Utilities and Karl Guiler from Planning. Landscape codes serve as critical policy tools for municipalities seeking to balance development needs with environmental stewardship and climate resilience. These ordinances establish standards for vegetation, water use, and site design that directly influence a community's ability to manage stormwater, reduce urban heat islands, conserve water resources, and support local ecosystems. As Boulder prepares for intensifying climate impacts, an updated landscape code has become increasingly vital for ensuring new development contributes to community-wide resilience. Welldesigned landscape ordinances can drive significant water savings, enhance biodiversity, improve air quality, and create more livable neighborhoods while providing clear guidelines for developers and property owners. In order to inform our own code updates, we selected eight cities to interview, each a leader in one or more specific areas of their code, with a preference for cities with climates similar to Boulder. The cities interviewed included: 1. Washington D.C. 2. Seattle 3. Aurora 4. Fort Collins 5. Aspen 6. Denver 7. Bozeman 8. Castle Rock

Findings

Key takeaways that emerged during interviews, listed here as a set of best practices, include: • Involving community stakeholders in code development process • Providing a “menu” of options within code • Remaining adaptable and responsive– creating space for code to be a “living document” • Ensuring internal departments are aligned and proactively eliminating code conflicts • Planning for and allocating resources towards enforcement/follow-up • Implementing practices to encourage/support training for landscape professionals, especially with changing requirements (i.e. irrigation systems training, native grass installation, soil health practices, etc).

Attachment G - Summary of Feedback from Peer Communities

Interview Summaries:

Washington D.C. & Seattle Washington D.C. and Seattle implement innovative target-based landscape code programs, wherein developments must meet a minimum “score” by implementing sustainable land use practices from a menu of options (each practice with their own weighted contribution to the overall score). Different zones within the city must meet different minimum scores. Seattle was the first U.S. city to implement this style of code requirements (which they call “Green Factor”) in 2006, followed by Washington D.C. (“Green Area Ratio”) in 2013. Neither cities have yet conducted an official analysis of the impact of their programs, although Washington D.C. is currently working on some analyses. All representatives spoke positively about the program outcomes. A representative from Seattle said, “Developers like having a menu of options. For the most part it's not onerous for them to meet the requirements.” Aurora, CO Aurora is updating their Landscape Reference Manual, expected to be released at the end of June, which will now reference the Front Range Tree List but eliminate specific plant lists for shrubs and grasses due to species availability concerns. The city has implemented strict turf restrictions (no turf in residential front yards or curbside areas, limited to 45% of total area or 500 square feet in backyard) and offers water-saving incentives through their Grass Replacement Incentive Program (GRIP), with developers now embracing water-conscious practices after some initial resistance. Aurora provides flexible tree protection options, with developers removing trees split between replanting on-site versus contributing to the tree fund. Fort Collins, CO The city has at least 6 staff who participate in landscape reviews across departments (Planning, Zoning, Forestry, Parks, Water Conservation). They note that they could always use more help on the enforcement side, especially nearing and after landscape establishment to confirm good irrigation practices, plant care, etc. They reduced maximum water allowances from 15 to 11 gallons per square foot and are seeing positive trends toward more resilient, native landscape designs, though they face challenges with warm-season grasses like Bermuda that are low-water but offer minimal pollinator benefits and can be semi-invasive. Fort Collins prohibits all artificial turf and offers educational support through monthly "lunch and learns," but struggles with limited contractor expertise for native grass installation and the lack of suitable streetscape grass alternatives to Kentucky bluegrass. Their forestry department is actively updating code provisions amid developer pushback over tree valuation and mitigation costs. Aspen, CO Aspen has implemented a comprehensive water budget system with a maximum of 7.5 gallons per square foot per season, requiring separate tree hydrozones and mandatory third-party irrigation audits for Certificate of Occupancy approval, with winter inspection deferrals accepted through deposits. The city continuously updates their standards annually based on evolving technology and knowledge, emphasizing early stakeholder engagement with landscapers and irrigation professionals during the development process, though they noted missing opportunities for better internal stormwater

Attachment G - Summary of Feedback from Peer Communities

integration during their updates. Aspen's approach focuses on changing aesthetic preferences away from high-water turf toward native grasses and drought-tolerant landscapes, with the water budget system allowing creative flexibility while presenting enforcement challenges since calculations remain theoretical, and they're now tracking actual water usage as developments permitted under the new WELS standards reach completion after multi-year project timelines. Denver, CO Denver is undertaking a comprehensive landscape code update through the Denver Resilient Landscapes project launched in early 2025, prompted by outdated zoning rules with conflicting requirements and the state's non-functional turf legislation. The city has established an interagency working group meeting monthly to prevent code conflicts, convened a 15-20 person stakeholder advisory group, and is hosting 10 summer pop-up events across council districts to gather community feedback, particularly on residential zone challenges. Denver's phased approach includes a completed existing conditions analysis, an upcoming best-practices report due at the end of next month, followed by gap analysis and draft recommendations for stakeholder review, with final completion targeted for February/March 2026. The city aims to make resilient landscapes easier to implement while creating barriers for non-resilient designs, and notably lacks any current tree preservation rules, so developing these protections with caliper-based replacement and offsite mitigation options will be part of the update process. Bozeman, MT Bozeman currently has at least 10 staff who participate in landscape plan review across departments (Planning, Parks, Forestry, and Water Conservation), plus technicians who inspect and test sprinkler systems in the summer months. They conducted extensive community engagement including focus groups with local design professionals and stakeholders, resulting in a well-received landscape manual that established clear standards with a functional water budget calculator and comprehensive plant factor list to ensure consistent implementation. The city is considering practical adjustments including potentially allowing trees to be zoned with perennials and shrubs rather than requiring separate hydrozones due to contractor cost concerns in small areas, and reducing plant coverage requirements from 60% to 50%. They've implemented pre-installation contractor meetings to review requirements and inspect soil conditions to set contractors up for success. Castle Rock, CO Castle Rock employs three full-time staff members dedicated to landscape code review and enforcement, with specialized roles covering commercial/non-residential projects, residential development, and inspections. The city operates a four-tier water budget rate system based on evapotranspiration rates. They noted that their residential water budget system, largely unchanged since 2008, is "ready for a big makeover" and they plan to conduct aerial ground cover analysis in the coming year. Key operational insights from Castle Rock include the importance of consistent enforcement, with every project receiving inspection and full irrigation system testing. They've observed that "builders are rule followers" who will comply with requirements as long as enforcement is equitable. The city has adapted their code based on implementation results—after seeing excessive rock installations following turf restrictions, they updated requirements in 2024 to mandate minimum plant material using a specific formula. They emphasized the value of gradual implementation over dramatic

Attachment G - Summary of Feedback from Peer Communities

changes, recommending a multi-year phasing approach for major code updates, and highlighted that long-term maintenance (of irrigation systems) is crucial for achieving water savings goals.