Construction of the Locks
In 1891, the US Army Corp of Engineers began planning the canal project to produce the Chittenden-Ballard locks. James A. Moore had initially developed the plan to construct the locks, but some flaws in his program were brought to light when Hiram M. Chittenden became the Army District Engineer. He proposed to build the locks using concrete alternatively, as he knew the wood would degrade and eventually break, leading to Lake Washington draining into the Puget Sound. Chittenden also wanted to construct larger locks that would allow bigger vessels to pass through them. Though it took some convincing, Chittenden's plans went into action after gaining approval from the Lake Washington Canal Association in 1907.
Though Chittenden thought finishing this project would let him go out with a bang, he became ill and was forced to retire in 1909. Although he couldn't formally participate in the entirety of the construction, he still served as a consulting engineer for the project. Chittenden's dedication to the project thus led to the dedication of the locks in his name.
In August 1911, workers began building a cofferdam, a temporary structure surrounding the worksite to allow a dry work environment in a body of water. The cofferdam, reaching around 2,300 feet in length, took about a year to complete. 245,000 cubic yards were dredged to create the lock pit. Concrete pouring started in 1913 and was nearly complete in 1914. Nine lock gates were installed slightly before the completion of concrete pouring, and then the builders were faced with their final task of merging the two bodies of water separated by the locks.
Merging the freshwater of Salmon Bay with the waters from the Salish Sea was no easy task. To prevent harmful salt levels that could damage Salmon Bay's ecosystem, another cofferdam was built that included a spillway. The spillway regulates freshwater levels between the canal and the surrounding lakes, preventing their levels from reaching dangerous highs or lows.
After the cofferdam and spillway were built, it took nearly three weeks for water levels in Salmon Bay to be deep enough for ships to pass through. On July 25th, 1916, the Army Corp of Engineers sent one of their ships, Orcas, on a test run through the locks. After their success, the locks officially opened on August 3rd. Swinomish, a snag steamer boat, was the first vessel to pass through the locks on opening day and was again accompanied by Orcas.
