A canal and locks would be built from Salmon Bay on Puget Sound to Lake Union near Fremont. Ground was broken for the construction of the locks on November 10. A second canal would be built between Portage Bay at the east end of Lake Union and Union Bay on Lake Washington. Lake Washington would ultimately be lowered nine feet.
It took four and a half years to complete the canal. On May 8, 1917, ships were able to pass from Puget Sound through Lake Union to Lake Washington. On July 4, 1917, grand opening ceremonies were held.