Big Hill to Sand Lake 765-kV Transmission Project

Project Background and Need

In response to unprecedented load growth in the Permian Basin region, LCRA TSC and Oncor are jointly proposing to build and operate a new Electric Reliability Council of Texas-recommended 765-kilovolt transmission line to meet current needs for reliable power and support continuing development and economic growth.

Delivering reliable power to the Permian Basin has been a priority of Texas leaders for several years.

In 2023, the Texas Legislature enacted House Bill 5066, which required the Public Utility Commission of Texas to direct ERCOT to develop a reliability plan for the Permian Basin region. ERCOT, after opportunity for stakeholder feedback, published a reliability plan outlining several options for the Permian Basin region in July 2024. The PUC approved the Permian Basin Reliability Plan in October 2024 and, in April 2025, ordered 765-kV electric transmission import paths as part of the approved plan.

This project, which is a 765-kV import path project identified in the Permian Basin Reliability Plan, will help extend transmission service to areas where mineral resources have been found, help meet forecast load demands into the future and provide infrastructure to reduce interconnection times in areas without access to transmission service.

In addition to rapid growth in oil and natural gas demand, transmission distribution service providers in ERCOT have also provided demand projections indicating a significant increase in the number of non-oil and gas loads in the Permian Basin region.

Preliminary Routing

The study area for the new transmission line includes portions of Crane, Crockett, Ector, Irion, Pecos, Reagan, Reeves, Schleicher, Tom Green, Upton, Ward and Winkler counties. The new line will connect LCRA TSC’s new 765-kV Big Hill Substation planned for Schleicher County (which will be constructed adjacent to LCRA TSC’s existing 345-kV Big Hill Substation) to Oncor’s existing Sand Lake Switch in Ward County.  The proposed project end points are about 177 miles apart.

LCRA TSC proposes to construct, own and operate the eastern half of the project (connecting to the new 765-kV Big Hill Substation), and Oncor will construct, own, and operate the western half of the Project (connecting to the Sand Lake Switch).

The project requires LCRA TSC and Oncor to amend their certificates of convenience and necessity (CCNs) with the PUC. As part of the process, both utilities will seek input from state and local elected officials and various agencies to identify routing constraints to help determine potential locations for new transmission facilities and assess the project’s potential impacts. LCRA TSC and Oncor held open houses for the public to learn more about the project and provide feedback on the project and the preliminary proposed routing.

Latest Update – June 2025

LCRA TSC and Oncor held project open houses in Big Lake (June 9), McCamey (June 10) and Pecos (June 11). Interested parties can provide feedback through the project questionnaire.

Below are materials from the meetings:

• Licensing Process for New Transmission Facilities
• Texas Utilities Code Sec. 37.056
• Big Hill-Sand Lake Planning Map
• Big Hill-Sand Lake Constraints Map
• 765-kV Tangent Tower Drawing
• Environmental Review Exhibit
• Project Questions and Answers

Resources

Interactive mapping tool: Zoom in and out on aerial imagery that depicts preliminary alternate transmission line route segments and property line information obtained from the county appraisal district. You can also search for your property using the Tract ID number provided by Oncor. Note: High-speed internet is recommended.

Texas Landowner’s Bill of Rights (English) (Spanish)

Contact

Kelly Wells, LCRA Regulatory Case Manager Lead
512-578-1446
[email protected]

Miguel Alvarado, Oncor Regulatory Manager
214-486-3560
[email protected]