WhiteWater has sharply expanded the planned Eiger Express Pipeline, raising its design capacity to 3.7 billion cubic feet per day (Bcf/d) after securing new long-term transportation commitments, according to a filing dated Nov. 24, 2025. The Permian-to-Katy line was originally sized at 2.5 Bcf/d when announced in August 2025, but the upsized 48-inch mainline and added compression will not affect the targeted mid-2028 in-service date, pending regulatory approvals.
The expansion adds scale to one of the Permian Basin’s next major long-haul routes. The pipeline is being developed by a joint venture controlled by Matterhorn JV, which holds 70%, alongside ONEOK and MPLX at 15% each. Matterhorn JV is owned by WhiteWater, ONEOK, MPLX and Enbridge, with WhiteWater’s share backed by FIC and I Squared Capital. ONEOK and MPLX also maintain direct stakes in the Eiger Express venture, separate from their interests in Matterhorn, which already operates long-haul gas systems feeding Gulf Coast and LNG export markets.
The Eiger Express Pipeline is a long-haul natural gas project that reached a final investment decision in August 2025, setting in motion a roughly 450-mile system designed to move growing Permian Basin production to the Gulf Coast. Developers advanced the project after securing long-term transportation commitments from shippers, establishing the commercial foundation for a new route feeding one of the country’s largest energy hubs.
The project was initially designed to move up to 2.5 Bcf/d through a 42-inch pipeline crossing Texas, with supply sourced from multiple interconnections in the Midland Basin and from the Delaware Basin via the Agua Blanca Pipeline, jointly owned by WhiteWater, Enbridge, and MPLX. Subsequent project updates, including WhiteWater’s Nov. 24, 2025 expansion announcement, increased the planned mainline diameter to 48 inches and raised the system’s design capacity to 3.7 Bcf/d, while keeping the targeted in-service date at mid-2028 pending regulatory approvals.
WhiteWater and its co-investors, MPLX LP, ONEOK, Inc., and Enbridge Inc., made the project’s ultimate investment choice through their joint venture, Matterhorn. The transaction is supported by fixed transportation obligations from predominantly investment-grade shippers, locking in the project’s commercial foundation.
Equity in the Eiger Express will be split between the developers, with 70 percent majority interest under control of the Matterhorn JV. ONEOK and MPLX bought 15 percent direct interest apiece, with their joint holding reaching 25.5 percent and 22 percent with their stakes in the Matterhorn. The project follows other major investments by ONEOK and MPLX in Texas, including their $1.75 billion partnership on a Texas City export terminal and pipeline.
WhiteWater will build and operate the pipeline. Under regulation approval, the Eiger Express is expected for completion by mid-2028. While this project is poised to begin construction, similar initiatives nationwide continue to face significant hurdles. The Constitution Pipeline, a proposed natural gas pipeline running from Pennsylvania to New York, has been in planning for over 15 years and still awaits the necessary approvals after being denied in New York. Developers are now eager to revive and advance the project.
Eiger Express Pipeline Project Factsheet
Project Overview
Status: Final Investment Decision Approved
Project Type: Natural Gas Transportation Pipeline
Target Completion: Mid-2028 (pending regulatory approval)
Technical Specifications
Length: 450 miles
Initial design capacity: 2.5 billion cubic feet of natural gas per day (Bcf/d)
Updated/current design capacity: 3.7 billion cubic feet of natural gas per day (Bcf/d)
Pipe Diameter: 48 inches
Geographic Coverage: Across Texas
Route: Permian Basin to Houston market
Supply Sources
Primary Source: Multiple connection points in the Midland Basin
Secondary Source: Delaware Basin via Agua Blanca Pipeline
Agua Blanca Pipeline Ownership: Joint venture between WhiteWater, Enbridge, and MPLX
Project Partners & Ownership Structure
Development Partners
WhiteWater (Lead Developer)
MPLX LP
ONEOK, Inc.
Enbridge Inc.
Ownership Distribution
Matterhorn Joint Venture: 70% majority interest
ONEOK: 15% direct ownership (25.5% total including Matterhorn share)
MPLX: 15% direct ownership (22% total including Matterhorn share)
Commercial Framework
Shipping Contracts: Long-term firm transportation commitments secured
Shipper Profile: Primarily investment-grade companies
Commercial Status: Backed by committed shipping agreements providing strong commercial foundation
Project Management
Construction Lead: WhiteWater
Operations Lead: WhiteWater
Regulatory Status: Pending regulatory approval
Timeline
Investment Decision: Completed
Estimated Completion: Mid-2028