List of Seattle megaprojects

This is a list of megaprojects in the Seattle area. For this list, a megaproject follows the often cited definition of $1 billion (2017 dollars) or more.

Name	Type	Status	Cost	Notes
Sound Transit 3	Transit	In progress	$54 billion[1]	Divided between several projects, to open between 2024 and 2041
Vancouver B.C.–Seattle–Portland high-speed railway	Transit	Proposed	$24–$42 billion[2][3]	Initiative of the Pacific Coast Collaborative between state and provincial governments
State Route 520 bridge replacement and corridor program	Road	In progress	$4.56 billion[4]	New bridge opened in April 2016, rest of corridor anticipated to be complete by 2029
Alaskan Way Viaduct replacement tunnel	Road tunnel	Completed in 2019	$4.25 billion (2009 est.)[5]
Amazon headquarters, Seattle	Office buildings	In progress	$4 billion[6]
East Link Extension	Transit line	In progress	$3.7 billion[7]	Scheduled to fully open in 2025
Lynnwood Link Extension	Transit line	Completed in 2024	$2.9 billion[8]
Interstate 405 (Eastside) improvements	Road	In progress	More than $2.8 billion[9]	2003 Nickel and 2005 Transportation Partnership Account: $1.5 billion; 2015 Connecting Washington package: $1.3 billion
Central Link, Seattle and Tukwila	Transit line	Completed in 2009	$2.44 billion[10]
Spring District, Bellevue	Urban development	In progress	$2.3 billion[11]	Scheduled to open in phases from 2017 to 2026
Puget Sound Gateway (SR 167 and SR 509)	Road	In progress	$1.989 billion[12]
Northgate Link tunnel	Transit tunnel	Completed in 2021	$1.9 billion[13]
Brightwater Tunnel	Sanitation infrastructure	Completed in 2011	$1.8 billion[14]
University Link tunnel	Transit tunnel	Completed in 2012	$1.7 billion[15]	Completed $200 million under budget. Central Link light rail service began in 2016.
Interstate 5 HOV lanes in Tacoma and Fife	Road expansion	In progress	$1.6 billion[16]	Scheduled to be complete in 2022
Yesler Terrace redevelopment	Urban development	In progress	$1.5 billion[17]	May increase to $1.7 billion
Lincoln Square expansion, Bellevue	Urban development	Completed in late 2017	$1.2 billion[18]
Seattle–Tacoma International Airport third runway	Airport infrastructure	Completed in 2008	$1.1 billion[19]	Does not include $200 million in soundproofing for schools
Seattle seawall replacement	Shoreline infrastructure	Completed in 2017	$1.07 billion (2014 estimate)[20]
Mount Baker Tunnel	Road tunnel	Completed in 1986	Over $1 billion[21]	Earliest billion-dollar project on this list
Point Ruston	Urban development	In progress	$1 billion[22]
Snoqualmie Ridge	Master-planned community	Completed in 2018	$1 billion[23]	Made suburb of Snoqualmie the fastest growing city in Washington (2010)
Hewitt Avenue Trestle replacement (U.S. Route 2, Everett)	Road bridge	Proposed	$620 million to $2 billion[24]
Puget Sound salmon recovery–culvert replacement	Stream restoration	In progress	$3.7 billion[25]	Began in 1991, expanded by June 2018 U.S. Supreme ruling in favor of tribal fisheries rights. Projected to continue through 2030.[25]

Other Washington state megaprojects

Notable Washington state megaprojects outside the immediate Seattle area include the following:

• Hanford cleanup $113.6 billion
  • Hanford Vitrification Plant $12 to $16.8 billion^[26]
• WNP-3 and WNP-5 nuclear power plants up to $24 billion estimated to complete (cancelled, WPPSS default)
• Grand Coulee Dam $5.541 billion in 2017 dollars^[27]
  • Third Powerplant (completed 1980) $2.002 billion in 2017 dollars^[27]
• North Spokane Corridor (freeway): $1.49 billion^[28]
• Lower Snake River Wind Project phase I and II (Tucannon River Wind Farm) $1.33 billion^[29][30]
• Interstate 90 widening near Snoqualmie Pass: $1 billion^[31]

See also

• List of megaprojects
• List of tunnels in Seattle