New Natural Gas Pipeline Planned for Southwest, Aiming for 2029 Completion

PHOENIX, AZ – August 7, 2025 – A new natural gas pipeline, spearheaded by Transwestern Pipeline Company, LLC, is slated to traverse New Mexico and southern Arizona, delivering fuel to Arizona’s central valley by late 2029. The project aims to bolster the region’s energy infrastructure and provide utilities with a more reliable and cost-effective gas supply, according to Arizona Public Service (APS), a key stakeholder.

Addressing Growing Energy Demand

The pipeline is a response to increasing energy demands in the rapidly growing Phoenix metropolitan area and surrounding communities. Arizona’s population has surged in recent years, placing a strain on existing energy resources. APS, which serves approximately 1.3 million customers across Arizona, stated it intends to utilize the pipeline “when it is most reliable and cost-effective for our customers, in conjunction with other resources in our balanced portfolio.” This strategy reflects a broader trend among utilities to diversify their energy sources while maintaining affordability and grid stability.

Project Details and Timeline

Transwestern will be responsible for the construction and operation of the pipeline, while utilities will be the recipients of the gas it carries. The company anticipates completing construction by late 2029, with construction slated to begin in mid-2028. The exact route remains under development, but is expected to generally follow a path through New Mexico and southern Arizona towards the Phoenix Valley.

Vicki granado, a spokesperson for Transwestern, emphasized the company’s commitment to minimizing environmental impact.”Our focus is to develop the safest route with the least environmental impact,” she stated.The company plans to prioritize utilizing existing rights-of-way, roads, and other previously disturbed areas to reduce the project’s footprint. Granado confirmed the pipeline will require approvals from the U.S.Army Corps of Engineers and the U.S. Fish and Wildlife Service,in addition to numerous state and local entities in both new Mexico and Arizona.

Regulatory Review and Public Input

The pipeline’s route will not be finalized until Transwestern completes a comprehensive regulatory review process. This includes detailed environmental,archaeological,and subsurface surveys. The Federal Energy Regulatory Commission (FERC) will play a central role in the approval process, and will host public open houses to gather feedback on the project. Transwestern will also conduct its own public outreach efforts. The FERC docket number for this project is currently unassigned, but will be publicly available once the formal application is filed, expected in early 2026.

Environmental Considerations and Potential Concerns

The project is likely to face scrutiny from environmental groups concerned about the potential impacts of pipeline construction on sensitive ecosystems, including the Sonoran Desert. Potential concerns include habitat fragmentation, disruption of wildlife corridors, and the risk of leaks or spills. Transwestern has stated it will conduct thorough environmental assessments and implement mitigation measures to address these concerns. The pipeline’s capacity is currently estimated at 800,000 dth (Decatherms) per day, though this figure is subject to change based on final design and demand projections.The pipeline will connect to existing Transwestern infrastructure in New Mexico, providing access to gas supplies from the Permian Basin and other production areas.

Sasha Hupka covers utilities and technology for The Arizona Republic. Reach her at sasha.hupka@arizonarepublic.com or 480-271-6387. Follow her on X: @Sashshhupka. Connect with her on linkedin: Sasha Hupka. Follow her on Instagram or Threads: @sashahup