Fire-Threat Maps and Fire-Safety Rulemaking

PUC Fire Safety Rulemaking Background

In October 2007, devastating wildfires driven by strong Santa Ana winds burned hundreds of square miles in Southern California. Several of the worst wildfires were reportedly ignited by overhead utility power lines and aerial communication facilities near power lines. In response to these wildfires, we created Rulemaking (R.) 08-11-005 to consider and adopt regulations to protect the public from potential fire hazards associated with overhead powerline facilities and nearby aerial communication facilities.

In 2009, we issued several decisions in R.08-11-005 that together adopted dozens of new fire-safety regulations. Most of the adopted fire-safety regulations consisted of new or revised rules in General Order (GO) 95. Several adopted fire-safety regulations apply only to areas, referred to as “high fire-threat areas,” where there is a higher risk for power line fires igniting and spreading rapidly. These high fire-threat areas are chosen by several maps that were approved on an interim basis. Each of the interim maps covers a different part of the State and uses its own method for showing high fire-threat areas, showing consistency and potential enforcement issues. To solve these issues, we started to create a single statewide fire-threat map to select areas with a higher risk for destructive power line fires and where stricter fire-safety regulations should apply.

In May 2015, we closed R.08-11-005 and began rulemaking  R.15-05-006 to complete the unfinished tasks in R.08-11-005. The general scope of R.15-05-006 was to complete these unfinished tasks:

1. Create and adopt a statewide fire-threat map that outlines the boundaries of a new High Fire-Threat District (HFTD) where the previously adopted regulations will apply,
2. Figure out the need for more fire-safety regulations in the HFTD, and
3. Revise GO 95 to include a definition and maps of the HFTD, as well as any new fire-safety regulations.

The scope and schedule for R.15-05-006 was divided into two parallel tracks. One track focused on the development and adoption of a statewide fire-threat map. The second track focused on the identification, evaluation, and adoption of fire-safety regulations in the HFTD.

On December 21, 2017, we completed the second track of R.15-05-006 by issuing Decision (D.) 17-12-024 which adopted regulations to enhance fire-safety in the HFTD. On January 19, 2018 we adopted, via Safety and Enforcement Division’s (SED) disposition of a Tier 1 Advice Letter, the final CPUC Fire-Threat Map. The adopted CPUC Fire-Threat Map, together with the map of Tier 1 High Hazard Zones (HHZs) in the U.S. Forest Service- California Department of Forestry and Fire Protection’s (CAL FIRE) joint map of tree mortality HHZs, form the HFTD Map where stricter fire-safety regulations apply. Read more information about the Sept. 19, 2018: SED-CAL FIRE Joint Assessment and Recommendation Report on Fire-Wind Map.

Fire-Threat Maps & the High Fire-Threat District (HFTD)

Map Dissemination

Under the requirements of D.17-01-009, the Safety and Enforcement Division (SED) makes available the following maps that together make up the HFTD, which will direct future utility and communication infrastructure provider fire-safety activities in California. [Please use Internet Explorer or compatible browser to open files.]

1. CPUC Fire-Threat Map - high resolution pdf (8.5"x11")
2. CPUC Fire-Threat Map - high resolution pdf (poster size)
3. CPUC Fire-Threat Map - zip archive of native GIS files
4. USFS-CAL FIRE Joint Map of Tree Mortality HHZs - current version (NOTE: Scroll down to the “Tree Mortality Related High Hazard Zones” section on the CAL FIRE webpage. Click link to download the Tier 1_HighHazardZones which is used as CPUC HFTD Zone 1.)

In addition to the mandated map products required for posting in D.17-01-009 and provided above, supplemental map products are available below:

1. HFTD Map - high resolution pdf (8.5"x11")
2. HFTD Map - high resolution pdf (poster size)
3. HFTD Map - GIS web app viewer 

The HFTD Map provides a single map representing all parts of the HFTD from both map sources (i.e. CPUC Fire-Threat Map and Tree Mortality HHZ Map).

Interim Maps

The fire-safety regulations below require a map to define "high fire-threat areas" where these regulations apply. The interim maps adopted in R.08-11-005 consisted of these three fire-threat maps below:

1. A wildland fire-threat map prepared by the California Department of Forestry and Fire Protection’s (CAL FIRE) as part of its Fire Resource and Assessment Program (FRAP).  This map is often referred to as the "FRAP Map."
2. A modified FRAP Map developed by San Diego Gas & Electric (SDG&E) for its own service territory. This is sometimes referred to as the "SDG&E fire-threat map."
3. A map developed by communications utilities (see page 262 of D.12-01-032) to identify areas where there is an increased risk for utility-associated wildfires. This map is oftentimes referred to as the "Reax Map."

The Reax Map outlined high fire-threat areas in Northern California where regulations applied.  Except for SDG&E’s service territory, the FRAP Map outlined high fire-threat areas in Southern California where the previously identified regulations applied. The SDG&E fire-threat map was used for SDG&E’s service territory.  

CPUC Fire-Threat Map

In 2012, we created a statewide map designed specifically to show areas where there is an increased risk for utility associated wildfires. The CPUC Fire-Threat Map, started in R.08-11-005 and continued in R.15-05-006. 

We used a multistep process to develop the statewide CPUC Fire-Threat Map. The first step was to develop Fire Map 1 (FM 1), an agnostic map that shows California areas where there is a higher risk for the ignition and rapid spread of powerline fires due to strong winds, abundant dry vegetation, and other environmental conditions. These are the environmental conditions associated with the catastrophic powerline fires that burned 334 square miles of Southern California in October 2007. FM 1 was developed by CAL FIRE and adopted by us in Decision 16-05-036.

FM 1 served as the foundation for the development of the final CPUC Fire-Threat Map.  The CPUC Fire-Threat Map describes the boundaries of a new HFTD where utility infrastructure and operations will have stricter fire‑safety regulations. The CPUC Fire-Threat Map incorporates the fire hazards associated with past powerline wildfires besides the October 2007 fires in Southern California (e.g., the Butte Fire that burned 71,000 acres in Amador and Calaveras Counties in September 2015) and ranks fire-threat areas based on the risks that utility-associated wildfires pose to people and property. 

The main people handling the development of the CPUC Fire-Threat Map was a group of utility mapping experts known as the Peer Development Panel (PDP), with oversight from a team of independent experts known as the Independent Review Team (IRT). The members of the IRT were selected by CAL FIRE and CAL FIRE served as the Chair of the IRT. The development of CPUC Fire-Threat Map includes input from many stakeholders, including investor-owned and publicly owned electric utilities, communications infrastructure providers, public interest groups, and local public safety agencies. 

The PDP served a draft statewide CPUC Fire-Threat Map on July 31, 2017, which was later reviewed by the IRT. On October 2 and October 5, 2017, the PDP filed an Initial CPUC Fire-Threat Map that reflected the results of the IRT’s review through September 25, 2017. The final IRT-approved CPUC Fire-Threat Map was filed on November 17, 2017. On November 21, 2017, SED filed on behalf of the IRT a summary report detailing the production of the CPUC Fire-Threat Map (referenced at the time as Fire Map 2). Interested parties were able to submit alternate maps, written comments on the IRT-approved map and alternate maps (if any), and motions for Evidentiary Hearings. No motions for Evidentiary Hearings or alternate map proposals were received. On January 19, 2018 we adopted, via (SED) disposition of a Tier 1 Advice Letter, the final CPUC Fire-Threat Map.

You can access the GIS web viewer here: https://ia.cpuc.ca.gov/firemap/ and click on the magnifying lens icon in the upper right corner to show the search bar. From there you can enter addresses and zoom in to a fairly fine scale with street level detail.

High Fire-Threat District (HFTD)

In D.17-01-009, as changed by D.17-06-024, we adopted a work plan for the development and adoption of the CPUC Fire-Threat Map, which is one part of the HFTD. Following these decisions, the HFTD is made up of two maps:  

1. Tier 1 High Hazard Zones (HHZs) on the U.S. Forest Service-CAL FIRE joint map of Tree Mortality HHZs ("Tree Mortality HHZ Map").
2. Tier 2 and Tier 3 fire-threat areas on the CPUC Fire-Threat Map

The Tree Mortality HHZ Map is an off-the-shelf map. Tier 1 HHZs are zones near communities, roads, and utility lines, and are a direct threat to public safety. Tier 2 fire-threat areas outline areas where there is a higher risk (including likelihood and potential impacts on people and property) from utility related wildfires. Tier 3 fire-threat areas outline areas where there is an extreme risk (including likelihood and potential impacts on people and property) from utility related wildfires. 

It should be noted that:

1. Tier 2 and Tier 3 fire-threat areas on the CPUC Fire-Threat Map may overlap Tier 1 HHZs on the Tree Mortality HHZ Map,

2. The Tree Mortality HHZ Map is not owned or maintained by the CPUC, and 

3. The Tree Mortality HHZ Map is updated more often (about once a year) than the 10-year update cycle adopted by the above-mentioned decisions for the CPUC Fire-Threat Map.

The fire-safety regulations described below apply only to areas designated as "high fire-threat areas" following the adopted interim maps. The HFTD is intended to represent an area based, in part, upon a mapping product (i.e. CPUC Fire-Threat Map) developed specifically for the purpose of scoping utility regulations.