Rule 20 Underground Conversions

Undergrounding Electric Lines and Equipment

The California Public Utilities Commission's (CPUC) Rule 20 sets policies and procedures for the conversion of overhead power lines and other equipment to underground facilities, a process called "undergrounding." We support undergrounding because it provides substantial aesthetic benefits to local communities.

Under Rule 20, undergrounding projects are financed by utility rate money, combined rate funds and local tax proceeds, or private funds, depending on whether Rule 20A, Rule 20B or Rule 20C provisions apply. View Rule 20 tariff, as approved by the California Public Utilities Commission.

About Rule 20A

Rule 20A projects are paid for by all SCE customers and ratepayers, not just those who live in locations where facilities will be undergrounded. City and county governments choose these projects, using a process that includes public participation.

To qualify for full funding through utility rate proceeds, projects must produce a benefit to the general public, not just customers in the affected area, by satisfying one or more of these criteria:

  • Such undergrounding will avoid or eliminate an unusually heavy concentration of overhead electric facilities;
  • The street or road or right-of-way is extensively used by the general public and carries a heavy volume of pedestrian or vehicular traffic;
  • The street or road or right-of-way adjoins or passes through a civic area or public recreation area or an area of significant scenic, cultural, and/or historic interest to the general public;
  • The street of road or right-of-way is considered an arterial street or major collector road, as defined the California Department of Transportation’s California Road System functional classification system; or
  • Wheelchair access is limited or impeded by existing above ground electric and/or telecommunications infrastructure including pad mounted facilities on sidewalks or in other areas in the pedestrian right-of-way that is otherwise not compliant with the Americans with Disabilities Act.

SCE allocates rate funds to communities for undergrounding using formulas provided in the Rule 20 tariff. Allocated funds are determined by the ratio of customers served by overhead facilities to the total number of customers in the community, and the fraction that customers in the community represent of all SCE customers.

CPUC’s Decision (D.)21-06-013, issued on June 3, 2021, in the Rule 20 Order Instituting Rule Making (OIR), required SCE to discontinue allocating new Rule 20A work credits after December 31, 2022. SCE’s last allocation of work credits will, therefore, be a 2022 allocation added to city and county balances in January of 2022. After SCE’s last annual allocation of work credits, cities and counties will continue to be able to complete Rule 20A projects within their available work credit balances.

About Rule 20B

If an area is not eligible for Rule 20A or if local government cannot or chooses not to rely on the Rule 20A allocation process, Rule 20B allows rate funds to subsidize an undergrounding project.

The undergrounding is paid for by the applicant with a credit or subsidy for the cost of new equivalent overhead system and removal of the existing overhead system. The credit will vary, but is usually in the range of 20-25%

A Rule 20B can be performed provided the overhead facilities to be undergrounded are a minimum distance of one block or 600 feet, whichever is less

About Rule 20C

Rule 20C enables individual property owners to pay for undergrounding electric lines and equipment if neither Rule 20A nor 20B applies.

A Rule 20C does not have a minimum distance or need to meet any other qualifying criteria as with a Rule 20A or Rule 20B. The applicant pays for the full cost of undergrounding. A credit is provided for the estimated salvage value of the removed electrical facilities.

At a local government's request, SCE will meet with government officials and residents to provide status on any Rule 20 project that has been approved.

  • SCE will meet with local officials every 30 days, if the local government requests it, to discuss Rule 20 project construction.
  • See Southern California Edison’s Electric Rule 20 Guidebook for full details of how Rule 20 works.
  • A local government can contact their SCE region manager or send inquiries to the Rule 20 Project Management inbox at A second phase of Rule 20 changes is currently under study. Topics include competitive bidding, incentive mechanisms, establishing a point after which no more overhead facilities will be constructed, and cost recovery for telecommunications undergrounding projects.

Frequently Asked Questions

What is Rule 20?

Rule 20 is a set of policies and procedures established by the California Public Utilities Commission to regulate the conversion of overhead electric equipment to underground facilities, a process called "undergrounding". Rule 20 determines the level of ratepayer funding for different undergrounding arrangements. See Rule 20ARule 20B, and Rule 20C above.

How Can I Learn If My Neighborhood Is Scheduled For Undergrounding?

You should contact your local city or county government offices to find out if your neighborhood is scheduled for a Rule 20 project or to learn the process used in your locality for Rule 20A and Rule 20B projects.

How Do I Start a Rule 20C Project?

To find out how to begin a Rule 20C project, contact the applicable Service Planning Office which can be found in Electrical Service Requirements (ESR-1) using Table 1-1 Service Planning Office – Telephone Numbers and Locations in conjunction with Table 1-2 Service Center Planning Directory. This manual can be located under SCE Manuals on the SCE website or use the hyperlink on Appendix E of the SCE Electric Rule 20 Guidebook or contact the SCE Customer Service Center at 800-655-4555.

Will Power Outages Decrease After Undergrounding? Will Outages Be Longer Or Shorter?

Our information is inconclusive. However, we believe, that in areas that experience frequent heavy winds, outages decrease when lines are undergrounded. In wetter areas, outages may tend to increase due to the effect of water seepage on underground equipment.

The information we have, while inconclusive, seems to indicate that outages tend to be longer with underground facilities, simply because it is more difficult to find problems and replace equipment underground.

Are Underground Facilities More Or Less Expensive than Overhead?

Underground facilities are more expensive to install and maintain than overhead equipment. The cost of overhead equipment is about 20% of the cost of underground. Maintenance costs for underground facilities are also higher than for overhead.

Does A Project Have to Meet All the Criteria to Qualify as A Rule 20A Project?

To qualify for undergrounding as a Rule 20A, the project must meet one qualifying criteria from the Rule 20 tariff and be one city block or 600 feet.

Aren't Rule 20A Funds Really the Government Agency’s Money?

SCE is required to pay for undergrounding projects up front with money it raises through investor funds. The money is not collected from customers in rates ahead of time. SCE recovers the cost of a Rule 20A project once it has been constructed.

Does Allocations Not Represent Actual Funding?

Allocations are a planning tool for local governments. They represent a qualified right to direct assign a portion of SCE's anticipated capital budget to qualified Rule 20A projects. Some of the language in the Rule 20 tariff seems to suggest that the allocations represent actual funds, but that is not the case.