The Soo Locks are the lynch pin of the Great Lakes Navigation System.  

88 percent of the commercial commodities are carried by ships transiting the Soo Locks and are limited by size to the Poe Lock.

Due to aging and deteriorating infrastructure, unscheduled outages are increasing.  

The economic impact of a 30-day unscheduled closure of the Soo Locks is $160,000,000, in 2015 numbers.