Big Hill to Sand Lake 765-kV Transmission Project
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 – January 2026
Application filed with the Public Utility Commission of Texas
LCRA TSC and Oncor filed an application with the Public Utility Commission of Texas (PUC) on Jan. 15 to amend their Certificates of Convenience and Necessity (CCN) for the Big Hill to Sand Lake 765-kV Transmission Line Project under PUC Docket No. 59182.
The application includes data on 173 alternative routes that range from approximately 197 to 222 miles. Numerous other routes could be created by combining the filed segments into additional routes. The order of the routes included in the application is numerical and does not signify any preference on LCRA TSC’s or Oncor’s part as to which route is ultimately approved. Note that all routes and route links included in the application are available for selection and approval by the PUC.
Please see Attachment 1, Environmental Assessment and Alternative Route Analysis to view the various route segments. You can also view the routes and route segments using the Interactive Mapping Tool.
Under the PUC procedural rules, the deadline for intervention in PUC Docket No. 59128 is Feb. 16, 2026. If approved by the PUC, the transmission line is scheduled to be energized by the end of 2030.
- Big Hill-Sand Lake Notice Map
- CCN Application
- Environmental Assessment and Alternative Route Analysis
- Link Composition of Alternative Routes
- Environmental and Land Use Constraints Map
- ERCOT’s Permian Basin Reliability Plan Study Report (July 25, 2024) and Addendum (September 11, 2024) (together, “Permian Basin Reliability Study”)
- Commission Order Approving the Permian Basin Reliability Plan (October 2024)
To view the complete filing package please see PUC Docket No. 59182.
Previous Project Updates
November 2025
Latest Update – November 2025
LCRA TSC and Oncor have held public meetings and collected feedback about the projects and preliminary route segments. LCRA TSC, Oncor and the project routing consultant are reviewing and evaluating the feedback in preparation for the joint CCN project filing, which is expected in January 2026. For more information on the filing process and future steps, please see the Licensing Process for New Transmission Facilities document. At the time of the filing, notice will be mailed to any property owner whose land is crossed by a proposed route or who has a habitable structure within 500 feet of the centerline of the project.
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
June 2025
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 provided feedback through a project questionnaire.
Map
Project Timeline
| 2025 | |
|---|---|
| January-May | LCRA TSC/Oncor identify preliminary alternative route segments |
| April | Public Utility Commission of Texas orders LCRA TSC and Oncor to build 765-kV transmission line |
| June | Public open houses: Big Lake Monday, June 9, 2025, 5-7 p.m. Reagan County High School Cafeteria 1111 East 12th Street Big Lake, Texas McCamey Tuesday, June 10, 2025, 5-7 p.m. McCamey 4-H and Community Center 18001 U.S. Highway 67 McCamey, Texas Pecos Wednesday, June 11, 2025, 5-7 p.m. Reeves County Civic Center 1300 S. Cedar Street Pecos, Texas |
| 2026 | |
| January | Filing of joint application with PUC to amend CCNs |
| Winter/early spring | PUC review and processing of application |
| Summer | PUC decision and final route determination expected |
| 2030 | |
| Summer | Estimated project in-service date |
Contact
Kelly Wells, LCRA Regulatory Case Manager Lead
512-578-1446
[email protected]
Miguel Alvarado, Oncor Regulatory Manager
214-486-3560
[email protected]
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