Riverside Public Utilities

Hunter Substation Replacement Project

About the Project

At Riverside Public Utilities (RPU), our commitment is to continuously enhance the service we provide to you. With this mission in mind, we are excited to announce the Hunter Substation Replacement Project. This project aims to address the reliability and capacity challenges of the current, aging Hunter Substation by proposing its retirement and the construction of a modernized substation. The new, state-of-the-art substation is planned to be constructed on an adjacent lot, purchased by RPU in 2018, ensuring a seamless transition in service.

Located at 1731 Marlborough Avenue in Riverside, CA 92507, the original Hunter Substation was established in the early 1960s. It currently serves around 4,700 customers, including both residential and business users in the Hunter Industrial Park, Northside communities, and University neighborhoods near the 215/60/91 Freeway interchange.

The existing facility includes four 69,000 volts sub-transmission lines, twelve 12,000 volts distribution circuits, and three 4,000 volts distribution circuits. The new Hunter Substation is designed to improve system reliability and support growing power demands and support regional development initiatives. The upgraded facility will operate at 69,000 Volts to 12,000 Volts (69kV/12kV), increasing the number of 12kV distribution circuits to 20. This expansion is designed to manage future power requirements, further the conversion of 4kV circuits to 12kV, and relieve the existing load on neighboring Riverside and University substations, thereby ensuring a robust and reliable power supply for our community.

Project Map

Project Construction

The construction of the project will be broken down into two phases.

Phase 1:

  • Construction of a new 69/12kV Hunter Substation built adjacent to the existing Hunter Substation that will remain in service while the new substation is constructed.
  • Connection to four existing 69kV sub-transmission lines and connection to existing 12 distribution circuits.
  • Construction of new underground 12kV distribution getaways.

Phase 2:

  • Decommissioning and demolition of the existing substation.

Existing Hunter Substation

Proposed New Hunter Substation

Project Status

The City of Riverside Council approved the Mitigated Negative Declaration (MND) and the project in March 9, 2021

Anticipated Project Timeline


Anticipated Date

Approval of the California Environmental Quality Act (CEQA) Mitigated Negative Declaration (MND)

March 9, 2021

Award of contract to design-built contractor

June 2024

Completion of design

June 2025

Phase 1 Construction

June 2027

Phase 2 Construction

December 2027

Project Benefits

  • Enhanced System Reliability: Upgrade with new equipment to replace outdated substation components that have surpassed their lifespan and are prone to service failures.
  • Increased Electrical Capacity: Expand capacity to meet both current and anticipated future electrical demands in the surrounding areas. Resolve seismic vulnerabilities and the current substation's unreliable setup.
  • Operational Efficiency: Streamline operations for improved efficiency across the board.
  • Support for Infrastructure Upgrades: Facilitate the ongoing transition from 4kV to 12kV systems, enhancing the overall network's performance.
  • Reduced Substation Overload:Mitigate the stress on adjacent substations and boost contingency capabilities, ensuring a more reliable power supply.

Contact Information

For questions or concerns regarding this project, please contact:

Fady Megala, P.E.
Principal Engineer
(951) 826-5873
[email protected]