About Utilities Underground Conversion Projects
Since 1965, the City of Palo Alto Utilities (CPAU) has administered an ongoing program to convert overhead utility lines, including electric, telephone, and cable TV facilities, to underground.This staff report provides some historical background on the City’s undergrounding program.
- Read our Frequently Asked Questions about utilities underground conversion projects.
- View the Utilities Underground Map of existing underground districts and proposed underground districts.
- Underground Utility District 47 - Forest, Middlefield, Lincoln & Cowper
- Underground Utility District 46 - Charleston/Arastradero & El Camino Real
New Utilities Underground Conversion Projects
- The City's Electric Capital Improvement Program Map shows the proposed areas for new utilities underground projects.
- Read about the City's policy on converting electric and communication facilities to underground.
Rebuilding Existing Utilities Underground Districts
CPAU not only develops new underground districts but, because of the limited life expectancy of equipment, proactively rebuilds older districts to minimize the risk of unplanned outages. This rebuild program aligns with CPAU’s 2018 Strategic Plan for a proactive infrastructure replacement program, based on planned replacement before failure to support reliability and resiliency (Priority 4, Strategy 1). This work is necessary to help ensure electric service reliability, improve safety conditions surrounding the electrical equipment, and is for the benefit of all customers in the area.
- Read Frequently Asked Questions about utilities underground district rebuilds.
Current Utilities Underground District Rebuilds in Progress
- Rebuild Underground District 24 - Downtown University
- Rebuild Electric System Stanford Hospital/Mall Area
Upcoming Utilities Underground District Rebuilds
- This Electric Capital Improvement Program Map shows which existing utilities underground areas the City plans to rebuild over the next few years.
What is Involved in a Utilities Underground Rebuild Project
Utilities underground rebuild projects involve the redesign of the underground electric system to current design practices. This includes replacement, where necessary, of cables, switches, transformers, and associated equipment, as well as conversion of the primary voltage from 4,160 Volt (V) to 12,470 V. Per City policy, Section B(3) of City of Palo Alto Rule and Regulation 3 (Description of Utility Services), above ground padmount equipment is required for all new underground electric construction. Where possible, submersible equipment will be replaced with padmount equipment which is more reliable, safer to operate, and more easily maintained.
- View a recent staff report and presentation to the Utilities Advisory Commission about requirements for pad-mounted equipment in underground electric construction.
- This includes a discussion about exceptions to the standard rebuild design for Utilities Underground District 15, in the Green Acres neighborhood.
- Electric utilities cite safety as a primary reason to upgrade subsurface electrical equipment to above ground pad mounts. Sempra Energy provides an explanation in their project management fact sheet.