The Hiram M. Chittenden Locks, or Ballard Locks, is a complex of locks at the west end of Salmon Bay in Seattle, Washington's Lake Washington Ship Canal, between the neighborhoods of Ballard to the north and Magnolia to the south.

Prior to construction

thumb|All sections of the [[Lake Washington Ship Canal, fully completed in 1934 ]]

As early as 1854, there was discussion of building a navigable connection between Lake Washington and Puget Sound for the purpose of transporting logs, milled lumber, and fishing vessels. Thirteen years later, the United States Navy endorsed a canal project, which included a plan for building a naval shipyard on Lake Washington. In 1891 the U.S. Army Corps of Engineers started planning the project. Some preliminary work was begun in 1906, and work began in earnest five years later under the command of Hiram M. Chittenden. The delays in canal planning and construction resulted in the US Navy building the Puget Sound Naval Shipyard in Bremerton, Washington, which is located across the Sound from Seattle.

Construction

thumb|upright=1.2|Construction plan of Locks complex, showing various [[cofferdams holding water back from locks under construction, cross section of locks, and location of surrounding buildings including Administration Building and Cavanaugh House.]]

thumb|Aerial view of the locks from the west

In early 1909, the Washington State Legislature appropriated $250,000, placed under the control of the Corps of Engineers, for excavation of the canal between Lake Union and Lake Washington.

Function

thumb|upright=1.2|Ballard Locks and surrounding grounds

The locks and associated facilities serve three purposes:

  • To maintain the water level of the fresh water Lake Washington and Lake Union at above sea level, or more specifically, above Puget Sound's mean low tide. the locks were formally opened on July 4, 1917, although the first ship passed on August 3, 1916. They were named after US Army Major Hiram M. Chittenden, the Seattle District Engineer for the Corps of Engineers from April 1906 to September 1908.]]

The locks can elevate a vessel , from the level of Puget Sound at a very low tide to the level of freshwater Salmon Bay, in 10–15 minutes. The locks handle both pleasure boats and commercial vessels, ranging from kayaks to fishing boats returning from the Bering Sea to cargo ships. Over 1 million tons of cargo, fuel, building materials, and seafood products pass through the locks each year. Cedar River originally flowed into the Duwamish River along with the White River from the South. White River was rerouted into the Puyallup River. Cedar and White Rivers did support significant Salmon runs but also created severe flooding conditions for the early settlers. The rerouting of these two major rivers was a mixed blessing, while reducing flood threats, the Duwamish River salmon runs were decimated. To rectify this situation, salmon runs were rerouted through the Locks, which included introducing a major run of Sockeye Salmon using stock from Baker River, Washington.

The ladder was designed to use attraction water: fresh water flowing swiftly out the bottom of the fish ladder, in the direction opposite which anadromous fish migrate at the end of their lives. However, the attraction water from this first ladder was not effective. Instead, most salmon used the locks. This made them an easy target for predators like Herschel the sea lion; also, many were injured by hitting the walls and gates of the locks, or by hitting boat propellers.

  • US Army Corps of Engineers, Seattle District: Lake Washington Ship Canal and Hiram M. Chittenden Locks
  • Corps of Engineers Foundation http://www.ballardlocks.org