Santa Cruz Reliability Project North

The Santa Cruz Reliability Project is designed to reduce the potential for a major, sustained outage in Santa Cruz County. Power outages would be less frequent and shorter because UniSource could supply energy from more than one direction to the substations that support service to residents, businesses, service providers and other customers in the area.

The Santa Cruz Reliability (SCR) Project North will strengthen the local energy grid by constructing a 138 kilovolt (kV) transmission line to connect the Kantor substation to the regional electric grid in Pima County. This project would improve service reliability for customers by beginning the process of converting the current radial line configuration to a looped transmission system.

The new single-circuit transmission line would be installed in rights-of-way on weathering steel monopoles. UniSource also would expand the Kantor Substation, extending the property boundary by about 20 acres to accommodate setback, security, and operations and maintenance requirements. The substation improvements would support reliability for customers, allowing UniSource to perform maintenance without interrupting circuit operations.

SCR North is the first of three phases UniSource is planning to improve the high-voltage transmission system serving Santa Cruz County.

SCR North would provide several benefits to customers in the area. The project would:

• Improve the reliability and resiliency of the electrical transmission system serving Santa Cruz County.
• Strengthen the regional electric grid.
• Reduce the frequency and duration of outages affecting residents, businesses and industries, including hospitals, schools, ports of entry and federal facilities.
• Expand energy capacity in the area to meet current and future energy needs without impacting service to existing customers.
• Support maintenance and other upgrades by allowing UniSource to perform work without interrupting system operations.

• Interactive Map
• Preliminary Segments Map
• Refined Segments Map

Mailings

• Newsletter No. 1 – April 2024
• Newsletter No. 2 – July 2024
• Newsletter No. 3 – March 2025
• Newsletter No. 4 – May 2025

Public Meetings  

• Public Open House No. 1
  • Display Boards – April 25, 2024
• Public Open House No. 2
  • Display Boards — March 20, 2025

Stakeholder Meetings

• Agency Briefing – April 23, 2024
• Green Valley Coordinating Council Meeting – April 25, 2024
• Agency Briefing – March 19, 2025

Handouts

• Opportunities and Constraints Map – April 2024

Under state law, UniSource must secure a Certificate of Environmental Compatibility (CEC) to construct the transmission line. The Arizona Power Plant and Transmission Line Siting Committee reviews CEC applications in a public process that allows neighbors and other stakeholders to provide comments. The Arizona Corporation Commission must review and approve the CEC before UniSource can begin construction.

UniSource plans to file the application for a CEC fall 2025, followed by a public hearing, that will be held in the vicinity of the project, before the Arizona Power Plant and Transmission Line Siting Committee. If approved, the first phase of the Santa Cruz Reliability Project is expected to be constructed and in-service by 2028, with the full project constructed and in-service by 2030.

Public input is an important part of UniSource’s planning process.

Identifying a suitable location for new transmission facilities involves several phases, each informed by public input. Area residents and other stakeholders can provide insight to help UniSource identify opportunities and constraints, areas to avoid and specific route segments.

Residents and other stakeholders can also help UniSource to evaluate and prioritize the importance of the criteria used to assess potential routes. Alternative route segments will be identified using multiple criteria, including some required by law and others deemed important by area residents and other stakeholders. These criteria will support the development of a preferred transmission line route.

We encourage area residents, property owners, businesses and other stakeholders to ask questions and share their input by:

• Filling out an online comment form
• Sending email comments to scrnorth@uesaz.com
• Calling 520-917-6635 and leaving a voicemail message
• Mailing a letter with comments to:

ATTN: Santa Cruz Reliability — North
P.O. Box 711
Mail Stop CB200
Tucson, AZ 85702