Army Corps opens EIS scoping for 100‑mile Cascade Renewable Transmission Project

Joe Brock, a National Environmental Policy Act specialist with the US Army Corps of Engineers Portland District, opened a virtual scoping meeting on Jan. 28 to begin environmental review of the Cascade Renewable Transmission Project and invited public input as the Corps prepares an environmental impact statement (EIS).

The Corps described the proposal as a new high‑voltage direct‑current (HVDC) transmission line roughly 100 miles long that would carry about 1,100 megawatts from generation east of the Cascade Mountains to load centers west of the Cascades. "The objective of the scoping process is to hear from you. We need your input to identify issues, alternatives, and potentially significant effects to consider in the EIS," Brock said during the opening presentation.

Why it matters: the Corps is the lead federal agency for the EIS and will evaluate whether to authorize the project under multiple authorities, including Department of the Army permission under section 14 of the Rivers and Harbors Act and permits under section 10 of the Rivers and Harbors Act and section 404 of the Clean Water Act. The decision will balance anticipated benefits against reasonably foreseeable detriments and consider compliance with the Endangered Species Act and the National Historic Preservation Act.

Project and schedule details provided by the applicant: Chris Hopper, representing Cascade Renewable Transmission LLC, described an underwater/underground cable bundle about 12 inches in diameter (two 6‑inch transmission cables plus fiber) with roughly 80 miles beneath the Columbia River and the remainder buried underground. Hopper said horizontal directional drilling (HDD) would be used at shore crossings (HDD transitions of about 40–50 feet where shorelines are sensitive), that the Corps likely will require average burial depths of at least 10–15 feet, and that installation would follow winter work windows to avoid fish migration seasons. He said the plan calls for two winter installation campaigns and converter stations of about 5 acres at each end to convert between AC and DC.

The Corps listed cooperating agencies that will participate in the EIS, including the Environmental Protection Agency, U.S. Coast Guard, Oregon Department of Energy (Energy Facility Siting Council), relevant Washington agencies, and several tribal governments. Cascade Renewable Transmission LLC will use HDR Engineering as its consultant; the Corps emphasized it will conduct an independent evaluation.

How to participate: Brock said the scoping period is 30 days, the draft EIS will have a 45‑day comment period, and the Corps has developed a two‑year schedule to complete the EIS process and make a decision. Scoping comments were requested by Feb. 4, 2026; the Corps provided an email address (CRT_EIS@USACE.ARMY.MIL) and a mailing address (Attention: Joe Brock, CRT project, P.O. Box 2946, Portland, OR 97208‑2946).

Next steps: The Corps will review scoping input to identify issues and alternatives for analysis in the draft EIS, publish the draft for public comment, and then prepare a final EIS and record of decision. The Corps reiterated that oral and written comments will be considered equally.