As of mid-2025, natural gas pipeline infrastructure continues to expand across the United States, with a growing list of new builds and extensions aimed at relieving regional constraints, unlocking stranded supply, and stabilizing prices in high-demand areas. For deregulated power and natural gas markets, especially those in Texas, the Northeast, the Mid-Atlantic, and in the West, these projects can directly influence end-user energy costs.
This post summarizes the most impactful non-operational pipeline projects currently proposed, permitted, or under construction, along with insights into their timing, regional benefits, and obstacles to completion.
Source: US Department of Energy
Permian Basin to Gulf Coast Projects (Texas)
- Hugh Brinson Pipeline
- Status: Final investment decision reached; construction underway
- Capacity: 2.2 Bcf/day
- Route: Waha Hub (West Texas) to Maypearl, south of Dallas
- Market Impact: Expands access from the Permian Basin to Texas’s growing power load centers and Gulf Coast markets. Expected to relieve takeaway bottlenecks, supporting more stable basis prices across ERCOT.
- Headwinds: Minimal permitting obstacles; timing largely hinges on construction logistics
- Blackcomb Pipeline
- Status: Final investment decision made; construction begins Fall 2025
- Capacity: 2.5 Bcf/day
- Route: Permian Basin to Agua Dulce, Texas
- Market Impact: Expected to be a major capacity addition for Permian producers. Could materially reduce price volatility and support growth in LNG and power demand along the Gulf.
- Headwinds: Steel procurement and labor market availability need to be observed for execution risk
- Gulf Coast Express (GCX) Expansion
- Status: Construction underway
- Capacity Addition: 570 MMcf/day
- Route: West Texas to South Texas
- Market Impact: Adds needed incremental flow to South Texas, helping to buffer LNG export volatility and reduce intrastate price dislocations
- Headwinds: Minor construction delays possible, but project is viewed as low-risk
Northeast and New England
- Constitution Pipeline (Revived)
- Status: Revival under active consideration; no full re-filing yet
- Capacity: 650 MMcf/day
- Route: Susquehanna County, PA to Schoharie County, NY
- Market Impact: Would bring Marcellus gas into upstate NY, easing winter constraints and reducing regional volatility. A significant benefit for power generators in NYISO and end users in constrained LDC zones.
- Headwinds: Environmental permitting and political opposition remain high; legal framework may need favorable change
- Iroquois Enhancement by Compression (ExC)
- Status: Under FERC review
- Capacity: ~125 MMcf/day
- Route: Along Iroquois system through NY and CT
- Market Impact: Could deliver more Canadian gas to NY/CT power generators, especially during peak winter periods
- Headwinds: CT regulators denied air permits in 2023; project faces uncertainty over emissions limits
- Tennessee 261 Upgrade Project
- Status: Delayed but active
- Route: Springfield, Massachusetts area
- Market Impact: Important for ISO-NE winter reliability. Would support dual-fuel capable power plants and firm gas users in Western MA
- Headwinds: Limited winter-only demand and siting opposition
- Empire North Expansion
- Status: Some segments deferred
- Route: Tioga County, PA to Corning and Elmira, NY
- Market Impact: Supports Marcellus takeaway into smaller New York markets. Useful for industrials and municipals with interruptible supply risk
- Headwinds: Demand uncertainty and limited downstream pipeline connectivity
- Consolidated Edison Infrastructure Enhancements
- Status: Ongoing under Smart Solutions framework
- Scope: System enhancements, not a single pipeline
- Market Impact: Relief for constrained NYC metro customers; could gradually reduce reliance on firm peaking contracts
- Headwinds: Complex regulatory coordination and capital planning limits the pace of improvement
Mid-Atlantic & Southeast
- Transco Power Express
- Status: Proposed
- Capacity: 950 MMcf/day
- Route: Pittsylvania County, VA to Transco mainline
- Market Impact: Would provide vital support to growing natural gas-fired generation in Virginia. Potential benefits for customers across PJM South
- Headwinds: Early-stage permitting and community opposition
- South System Expansion 4
- Status: Proposed
- Capacity: 1.3 Bcf/day
- Route: Georgia, Alabama, Mississippi
- Market Impact: Adds throughput in growing Sunbelt regions with rising gas power demand. Supports system flexibility during peak events.
- Headwinds: State-level permitting and interconnect complexity
Midwest
- Northern Lights 2025 Expansion (Northern Natural Gas)
- Status: Proposed
- Route: Enhancements to pipeline assets in MN and WI
- Market Impact: Would improve wintertime supply reliability in Upper Midwest markets. Important for industrials in deregulated areas of Wisconsin.
- Headwinds: Load growth is moderate, so timing may depend on firm capacity subscription
Western U.S. (California and Rocky Mountains)
- Altamont Green River Pipeline
- Status: Under construction
- Capacity: 150 MMcf/day
- Route: Uinta Basin (UT) to Western Midstream’s Chipeta plant
- Market Impact: Helps unlock trapped gas in Utah that could eventually flow westward toward California markets
- Headwinds: Limited downstream expansion options in CAISO territory
Note: As of now, there are no major greenfield intrastate pipeline projects in California under development. Most gas-fired plants are relying on existing SoCalGas and PG&E infrastructure, which remains highly capacity-constrained during winter.
From the Permian Basin to New York and from Virginia to Wisconsin, pipeline developers are aiming to bridge persistent gaps in capacity that can send gas and electricity prices soaring in deregulated markets. These projects, if completed on schedule, could alleviate localized volatility, enhance grid reliability, and create hedging opportunities for end users.
Yet, the regulatory landscape is complex and, in many regions, politically fraught. Projects in the Northeast face fierce environmental resistance, while those in Texas and the Gulf Coast benefit from more favorable permitting environments. End users and advisors should track these developments closely, especially where capacity additions could shift basis pricing or unlock stranded supply.
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