Wildfire Safety in Portola Terrace
Fire safety is a top priority for the Portola Terrace project. The proposed fire safety measures included in the project expand on existing wildfire prevention efforts already underway and include woodlands vegetation management, increasing access to the property and critical water supplies, ignition reduction, and undergrounding overhead electrical lines.
Portola Terrace Wildfire Prevention and Mitigation Measures
The Vegetation Management Plan (VMP) proposed by the Portola Terrace project was created by a team of leading fire experts in partnership with the Woodside Fire Protection District (WFPD) to address fire safety needs. This includes providing long-term strategies for reducing available fuel for wildfires and managing vegetation to minimize potential fire hazards, safeguarding ecological resources, and improving wildfire protection and safety on the property.
Responsible Fire Resilient Design
- The new, all electric residences will be constructed with fire-resistant building materials that meet or exceed the Town of Portola Valley’s Wildfire Preparedness Building Code and sustainably designed with native, drought-tolerant landscaping.
- The project includes a loop road with two points of entry and exit to and from Alpine Road and incorporates an access point for public safety personnel.
State Guidance: Best Practices and Mitigation of Wildfire Impacts
California Attorney General, Rob Bonta, recently released a “best practices” document that provides guidance to local agencies when considering projects in wildfire-prone areas. These best practices provide the Town of Portola Valley with a framework to use when evaluating a project’s wildfire risk. We are proud that the proposed design for the Portola Terrace Faculty Housing Project currently meets the above best practices outlined by the California Attorney General. We will continue to coordinate with the Town and provide updates throughout the CEQA review process.
The document provides guidance in these key areas:
Project Density should be considered, and local governments should strive to increase housing density and consolidate design, relying on higher density infill developments as much as possible.
Portola Terrace has been designed as a clustered development. Clustered developments include effective design, maintenance, and use of defensible space to protect from potential fire. When implemented with stringent fire-resistant building codes, compact neighborhoods are easier to defend with a smaller fire-fighting force and help achieve goals for climate resiliency. Denser neighborhoods often have lower amounts of flammable vegetation and more pavement, making them generally less flammable than larger homes on large lots.
Project Placement in the landscape relative to fire history, topography, and wind patterns also influences wildfire risk. The “best practices” document recommends that that projects be designed to limit development along steep slopes and amidst rugged terrain to decrease exposure to rapid fire spread and increase accessibility for firefighting.
The proposed project will be located at the base of the hills and close to Alpine Road. This location provides safety from potential uphill flow of heat and flames, as developments located on or at the top of steep slopes can be at particular risk from wildfire because fire and heat generally flow faster uphill.
Water Supply and Infrastructure should be analyzed by local governments to ensure there is enough water supply and infrastructure to address firefighting within the project site. Local governments should also consider undergrounding utilities and having on-site water supply or storage to augment ordinary supplies that may be lost during a wildfire.
The California Water Company has stated that they have adequate water supply to serve the Portola Terrace project. Stanford will be extending a water line approximately 1,700 feet south along Alpine Road from the Alpine Road/Westridge Drive intersection to the project site and create a dual connection from the two water main sources, providing an abundant source of water to the project site and surrounding area. The project will also install several new fire hydrants on the property and in the Alpine Road right-of-way to provide additional fire safety for Portola Terrace, nearby undeveloped areas, and immediate neighbors.
Evacuation and Emergency Access should be analyzed prior to the development's approval and include evaluation of the capacity of surrounding roadways, project impacts on existing evacuation plans, and proximity to existing fire services, among other factors. Development projects should consider the proximity to existing road and evacuation infrastructure.
The Portola Terrace project is located immediately adjacent to Alpine Road in keeping with recommendation that projects be in “proximity to existing road and evacuation infrastructure.” The project site design proposes an internal loop road with two points of ingress and egress to/from Alpine Road.
Fire Hardening Structures and Homes have been proven as an extremely effective measure for preventing structure loss during a wildfire. Developers should upgrade building materials and use installation techniques to increase the development’s resistance to heat, flames, and embers beyond what is required in applicable building codes.
Portola Terrace will construct “fire-hardened” homes that meet or exceed the Town’s Wildfire Preparedness Building Code. The project architectural firm, Seigel and Strain, has prepared a detailed analysis of the proposed project’s conformance with the Town’s Wildfire Preparedness Building Code amendments adopted on December 8, 2021.
Vegetation Management Plan Summary
The VMP is based on the results of two fire-behavior modeling programs used to assess the probability and intensity of fire on the property and identify ways to minimize the possibility of wildfires.
The modeling indicates that fire safety across the property significantly improves with the treatments specified in the VMP, all of which is included in the development application for the Portola Terrace project.
These images show the integrated hazard level on the property under current conditions and after implementation of the comprehensive treatments described in the VMP. As seen in the maps below, the entire property is re-characterized as only having areas of Lowest and Low Hazard after treatment.