Seattle - Central Waterfront seawall construction, 1934

The Alaskan Way Seawall is a

seawall A seawall (or sea wall) is a form of coastal defense constructed where the sea, and associated coastal processes, impact directly upon the landforms of the coast. The purpose of a seawall is to protect areas of human habitation, conservation ...

which runs for approximately along the

Elliott Bay Elliott Bay is a part of the Central Basin region of Puget Sound. It is in the U.S. state of Washington, extending southeastward between West Point in the north and Alki Point in the south. Seattle was founded on this body of water in the 1850s an ...

waterfront southwest of

downtown Seattle Downtown is the central business district of Seattle, Washington. It is fairly compact compared with other city centers on the U.S. West Coast due to its geographical situation, being hemmed in on the north and east by hills, on the west by ...

from Bay Street to S. Washington Street. The seawall is being rebuilt in the 2010s as part of a waterfront redevelopment

megaproject A megaproject is an extremely large-scale investment project. According to the ''Oxford Handbook of Megaproject Management'', "Megaprojects are large-scale, complex ventures that typically cost $1 billion or more, take many years to develop and ...

estimated to cost over $1 billion.

History

First slab of Seattle Central Waterfront seawall being placed, 1934

The seawall was built to provide level access to Seattle's

pier image:Brighton Pier, Brighton, East Sussex, England-2Oct2011 (1).jpg, Seaside pleasure pier in Brighton, England. The first seaside piers were built in England in the early 19th century. A pier is a raised structure that rises above a body of ...

s and supports the

Alaskan Way Viaduct The Alaskan Way Viaduct ("the viaduct" for short) was an elevated freeway in Seattle, Washington, United States, that carried a section of State Route 99 (SR 99). The double-decked freeway ran north–south along the city's waterfront for , ...

and

Alaskan Way Alaskan Way, originally Railroad Avenue, is a street in Seattle, Washington, that runs along the Elliott Bay waterfront from just north of S. Holgate Street in the Industrial District—south of which it becomes East Marginal Way S.— to Broad S ...

itself, which is a surface street. Completed in 1934, the seawall was built on top of wood

piling A deep foundation is a type of foundation that transfers building loads to the earth farther down from the surface than a shallow foundation does to a subsurface layer or a range of depths. A pile or piling is a vertical structural element ...

Replacement

Despite efforts to prevent marine pest damage when the seawall was designed, after the

2001 Nisqually earthquake The 2001 Nisqually earthquake occurred at on February 28, 2001 and lasted nearly a minute. The intraslab earthquake had a moment magnitude of 6.8 and a maximum Mercalli intensity of VIII (''Severe''). The epicenter was in the southern Puget So ...

, the

Seattle Department of Transportation The Seattle Department of Transportation (SDOT) is a municipal government agency in Seattle, Washington that is responsible for the maintenance of the city's transportation systems, including roads, bridges, and public transportation. The agency ...

found that

gribble A gribble /ˈgɹɪbəl/ (or gribble worm) is any of about 56 species of marine isopod from the family Limnoriidae. They are mostly pale white and small ( long) crustaceans, although ''Limnoria stephenseni'' from subantarctic waters can reach . ...

s had consumed all the wooden supports in some places. The

Washington State Department of Transportation The Washington State Department of Transportation (WSDOT or WashDOT, both ) is a governmental agency that constructs, maintains, and regulates the use of transportation infrastructure in the U.S. state of Washington (state), Washington. Establi ...

states that there is a 1-in-20 chance that it could be shut down by an earthquake within the next decade, and so plans have been underway to replace both seawall and viaduct. The seawall rebuild project was estimated to cost $350 million as part of an overall waterfront redevelopment budgeted in 2012 at $1.07 billion. The project is funded by a

bond measure A municipal bond, commonly known as a muni, is a bond issued by state or local governments, or entities they create such as authorities and special districts. In the United States, interest income received by holders of municipal bonds is often, ...

that was approved by Seattle voters in the November 2012 general election. Construction began in 2013 and was completed in 2017, more than a year late and costing $410 million.

References

External links

Washington State Department of Transportation Alaskan Way Viaduct and Seawall Replacement Project
Buildings and structures in Seattle Seawalls Dikes in the United States Engineering projects {{Washington-struct-stub

History

Replacement

See also

References

External links