How Kauai County Uses ArcGIS and Form-Based Codes for Wildfire Mitigation

Wildfires are reshaping communities across Hawaii. The 2023 Lahaina fire escalated rapidly, claiming over 100 lives, displacing 12,000 people, and destroying 3,000 properties. Estimated recovery costs reached $12 billion. In its wake, communities across Hawaii began asking how they could better protect themselves. Local governments responded, and investigators released reports to help planners address wildfire risk. These reports provided clear steps, but planners in Kauai County recognized the need for more detailed regulations to give elected officials, residents, and planners confidence in mitigation strategies.

The threat in Kauai County intensified in July 2024 when a wildfire nearly destroyed a historic plantation camp. These camps sit next to undeveloped wildland vegetation—classified by the US Fire Administration as part of the wildland urban interface (WUI)—making them especially vulnerable to fire. This proximity created an urgent need for resilient planning that could support both rebuilding and future development while maintaining safety and sustainability. Kauai’s leaders turned to geographic information system (GIS) technology, specifically ArcGIS Enterprise, and form-based codes to protect their communities and create a blueprint for wildfire mitigation.
 

To find the most effective wildfire mitigation strategies, Kauai County’s planning director, Kaʻāina Hull, sent staff to a wildfire conference and seminars across the US. At these events, staff heard firefighters and fire chiefs discuss the challenges of protecting communities, even in places like California with strong firefighting resources. Planners realized that changing the built environment—how buildings and neighborhoods are designed—was key to making communities safer.

As the only civic planners at these conferences, Kauai’s team walked away with more than a few ideas of what changes would make camp communities more fire-resistant. Specifically, they saw that form-based codes (FBC) could help shape safer camp communities by regulating building design and placement. These codes control setbacks, distances from vegetation, and other features that can reduce wildfire risk. Kauai had already adopted an FBC for one camp to preserve its character and saw that the right FBC would also help strengthen the camps’ fire resilience.

Using GIS tools like ArcGIS, planners began evaluating how these codes could address Kauai’s unique needs.

The county adopted a wildland urban interface regulatory ordinance alongside new form-based codes for additional camp communities. Since late 2024, planners have vetted the draft ordinance and identified a range of requirements for construction, home hardening, community vegetation management, and access. Due to the high cost of imposing fire-rated walls, many proposed regulations focus on preventing ember intrusion and making buildings more fire-resistant. These include building setbacks and noncombustible buffer zones to reduce the risk of urban infernos.
 

These parameters are centered on both design and location. To understand how these new regulations would shape neighborhoods, Kauai County planners relied on ArcGIS Urban, which lets them design and test city planning scenarios in interactive 3D. With ArcGIS Urban, they visualized how setbacks, buffer zones, and building heights would look across historic plantation camps.
 

For even more detailed modeling, the team used ArcGIS CityEngine. This tool allowed them to create realistic 3D representations of individual buildings, streets, and vegetation, helping planners see exactly how proposed changes would affect the landscape and improve fire resilience.
 

This process was not new to the team; they had successfully applied it for modeling sea level rise and did so again with Scene Viewer. This web-based application made it easy for county staff to link field photos, along with the measurements and key design characteristics of each house. The models included front, side, and rear renderings of houses. Other details added included thoroughfares, rear and side entries, detached accessory structures, and windows.

To visualize the new fire-resistant standards, Kauai County’s planning department established a five-foot buffer—referred to as Zone 0—around each home. This noncombustible zone prohibits vegetation and other flammable materials within five feet of any structure, significantly reducing the risk of embers igniting buildings during a wildfire. Then, planners used ArcGIS Urban to demonstrate the type and location of vegetation that would be allowed in the camp.
 

Kauai County administrative planning officer Alan Clinton recognized that as the project progressed, there were many similarities between this and their recent sea level rise project.

“We are using GIS to develop a whole new thesis around planning practices,” Clinton said. “Going forward, there will be a lot to deconstruct in this story.”

For planning departments across the country, especially those in areas susceptible to natural disasters such as wildfires, GIS presents an innovative, data-driven approach to mitigation. These technologies support efforts that can protect and preserve housing, lessen demand on public safety services, and lower costs for developers, homeowners, and government agencies.