Soo Locks cost estimate drops to about $2.62 billion; summer finish still expected

Army Corps Lowers Estimated Cost for Soo Locks New Lock to About $2.62 Billion; Summer 2030 Completion Still Planned

Federal engineers have revised the certified construction cost for the new lock at the Soo Locks complex in Sault Ste. Marie downward to approximately $2.62 billion, a reduction of nearly 13% from a prior estimate near $3.0 billion. The U.S. Army Corps of Engineers reported the change during a stakeholder update and confirmed the project remains on track for substantial completion in summer 2030.

Why the Cost Dropped

The primary reason for the lower number was the elimination of contingency amounts that had been held for various sub‑phases of the work. Those contingencies became unnecessary once contractors’ options were fully awarded, allowing removal of about $250 million of estimated project risk. The Corps noted the timing of contract awards was key to this reduction.

Funding, Remaining Needs and Budget Notes

Reported funding to date appears in different figures across briefings: one figure lists $2.321 billion funded so far, while another statement lists $2.231 billion. The Corps has indicated it expects to need about $103 million to continue construction into the 2027 fiscal year. A federal budget proposal for fiscal 2026 included $176 million for the project.

Current Work and Progress

The project is in its third phase, focused on building the new lock chamber. The Corps reports that more than $543 million to over $630 million of work has been completed to date, depending on which internal progress accounting is referenced. Completed items include deepening the upstream channel to 30 feet, rehabilitation and construction of approach walls, installation of a new pump, and construction of a new bridge to the power plant.

Major Site Milestones and Construction Details

Recent milestones include completion of a new bridge to the existing power plant in January and demolition of the century‑old Sabin Lock in July. The Davis Lock footprint has been filled to grade with bedrock and construction debris, and the third and final tower crane was erected during summer work. Those cranes, each between 240 and 270 feet tall, are among the tallest structures in the region and are enabling material movement across the site.

Bedrock excavation has been a main focus. Heavy hydraulic breakers, commonly called hoe rams, are breaking up bedrock to form foundations for a series of concrete wall segments known as monoliths. The design calls for 81 monoliths lining the north and south sides of the new chamber; just over 50 have been started and one has been completed. The concrete mix for these monoliths is very stiff and contains heavy 2‑ to 3‑inch aggregate.

Navigation Testing, Design Tweaks and Safety Features

A ship‑simulation study was carried out to confirm approach‑wall lengths and chamber alignment. That virtual testing led to a lengthened north upstream approach wall and the late addition of massive timber fenders on the south upstream approach wall to protect ships from scraping against concrete during maneuvers. The new lock will include hands‑free mooring technology to hold vessels safely as water levels change.

Project Scope, Timeline and Risks

The plan calls for a new lock 1,200 feet long and 110 feet wide, mirroring the existing Poe Lock. The new chamber will provide redundancy so the largest Great Lakes freighters — which the Poe Lock alone currently accommodates and which carry about 88% of tonnage through the waterway — can continue to move iron ore if the Poe Lock is unexpectedly out of service.

The project was originally authorized in 1986 and reauthorized in later legislation. Reauthorization totals have increased over time to account for labor shortages, supply chain issues and higher material costs; one reauthorization figure cited is $3.219 billion. Congress and federal partners are reviewing updated cost estimates and authorization needs. The Corps has transmitted updated cost information to authorization committees for consideration.

Economic Stakes and Oversight

The Soo Locks complex is critical to the U.S. steel supply chain, moving iron ore from Lake Superior to mills on lower Great Lakes. A federal study has estimated that an unscheduled six‑month outage of the Poe Lock could cause massive, short‑term economic harm — figures commonly cited include losses in the trillions of dollars and impacts on millions of jobs — which is a central rationale for completing a redundant, Poe‑sized lock.

Construction Tempo and Seasonal Limits

Construction activities continue year‑round where possible, but colder climate and ice seasons complicate work and require seasonal pauses. Contractors must cross active navigation channels and two working locks to access the site. Blasting operations began in February 2025 to support bedrock excavation tied to the Sabin Lock footprint and new monolith foundations.

Outlook

With the revised certified cost of about $2.62 billion, the Corps signals the project can remain on schedule for a summer 2030 finish if funding continues to flow as planned and market conditions do not deteriorate further. Congressional action on reauthorization levels and appropriations will influence final scheduling and any future adjustments.