What are the most expensive infrastructure projects currently in progress in Canada?

At a cost of $16 billion due to major budget overruns, the Site C hydroelectric dam in northeastern British Columbia is currently the country's most expensive infrastructure project. Construction first began in 2015, reservoir filling is scheduled to begin later in 2024, and power generation is expected to begin by late 2025.

This is followed by the $15.7 billion cost for the GO Train commuter rail expansion's corridor works, not including the project's separate early works at a cost of $10.5 billion and the Union Station upgrades through the CIBC Square project at $2 billion.

Two separate nuclear power plant refurbishment projects in Ontario rank third and fourth, with costs of $13 billion and $12.8 billion, respectively.

The fifth-most expensive project is Toronto's Eglinton Crosstown LRT, which is significantly over its budget, now at $12.6 billion, and delayed, with completion and opening possible by late 2024.

This compilation and ranking of the country's 100 most expensive infrastructure projects as of 2024 is by ReNew Canada. It is based on projects with their confirmed project cost, and in a state of active procurement (bidding process for a major contractor), assessment, design, and/or construction.

Moreover, these projects must also have funding support for inclusion in the ranking.

The top 100 projects have a combined project budget value of $293 billion. More than a quarter of these projects are public transit, one-fifth are other transportation such as bridges and highways, nearly a third are building developments such as hospitals, and 15 projects are wastewater plants or communications related.

Within the upper tier of the top 40 most expensive projects, 22 are located in Ontario, 10 projects are located in British Columbia, five projects are in Quebec, and two projects are in Alberta.

Ontario projects dominate seven of the top 10 list, including the $10.9 billion Ontario Line, which began construction last year towards a 2031 opening.

Montreal's REM rail rapid transit network is the country's ninth most expensive project, carrying a cost of $8 billion. The first phase opened last fall, and it is expected to reach full completion by 2027.

The eighth-most expensive project is Metro Vancouver Regional District's $9.9 billion Iona Island Wastewater Treatment Plant near Vancouver International Airport.

Some of BC's other most expensive projects include the $4.15 billion George Massey Tunnel replacement and Highway 99 corridor upgrade (No. 19), $4 billion SkyTrain Expo Line Surrey-Langley extension (No. 20), $3 billion Roberts Bank Terminal 2 super port in Delta (No. 28), $2.9 billion new Cloverdale Hospital and BC Cancer Centre in Surrey (No. 29), and the $2.8 billion SkyTrain Millennium Line Broadway extension in Vancouver, which will reach completion in 2026.

Within Alberta, the most notable projects are both rail rapid transit — the $4.9 billion Calgary Green Line LRT (No. 16) and the $2.6 billion Edmonton Valley Line West LRT (No. 32).

The 40 most expensive infrastructure projects in Canada

1. Site C Hydroelectric Dam, BC: $16 billion
2. GO Train Expansion — On-Corridor Works, Ontario: $15.7 billion
3. Bruce Power Nuclear Plant refurbishment, Ontario: $13 billion
4. Darlington Nuclear Plant refurbishment, Ontario: $12.8 billion
5. Toronto Eglinton Crosstown LRT, Ontario: $12.6 billion
6. Toronto Ontario Line rail rapid transit, Ontario: $10.9 billion
7. GO Train Expansion — Early Works, Ontario: $10.5 billion
8. Richmond/Vancouver Iona Island Wastewater Treatment Plant, BC: $9.9 billion
9. Montreal REM rail rapid transit, Quebec: $8 billion
10. Toronto Transit Commission (TTC) vehicles program, Ontario: $7.2 billion
11. Montreal Metro Blue Line East subway extension, Quebec: $6.4 billion
12. Gordie Howe International Bridge, Ontario: $6.4 billion
13. Mississauga-Brampton Hazel McCallion (Hurontario) LRT, Ontario: $5.6 billion
14. Toronto Transit Commission (TTC) Scarborough subway extension, Ontario: $5.5 billion
15. Parliament Hill's Centre Block rehabilitation, Ontario: $5 billion
16. Calgary Green Line LRT, Alberta: $4.9 billion
17. Toronto Eglinton Crosstown LRT West extension, Ontario: $4.7 billion
18. Ottawa LRT — Stage 2, Ontario: $4.7 billion
19. George Massey Tunnel replacement and Highway 99 corridor improvement project, BC: $4.15 billion
20. SkyTrain Expo Line Surrey-Langley extension, BC: $4 billion
21. Accelerated High-Speed Internet Program, Ontario: $3.9 billion
22. South Niagara Hospital, Ontario: $3.6 billion
23. Montreal Louis-Hippolyte Lafontaine Bridge-Tunnel, Quebec: $3.5 billion
24. Toronto Finch West LRT, Ontario: $3.4 billion
25. Hamilton LRT, Ontario: $3.4 billion
26. Toronto Don River and Central Waterfront & Connected Projects, Ontario: $3 billion
27. Ottawa Energy Services Acquisition Program's Energy Service Modernization, Ontario: $3 billion
28. Vancouver Fraser Port Authority new Roberts Bank Terminal 2 super port, BC: $3 billion
29. Surrey Cloverdale Hospital and BC Cancer Centre, BC: $2.9 billion
30. SkyTrain Millennium Line Vancouver Broadway subway extension, BC: $2.8 billion
31. Ottawa Hospital new campus, Ontario: $2.8 billion
32. Edmonton Valley Line West LRT, Alberta: $2.6 billion
33. Projet Hôpital Vaudreuil-Soulanges (new hospital), Quebec: $2.6 billion
34. Toronto New Hospital for Sick Children, Ontario: $2.4 billion
35. Burnaby Hospital redevelopment, BC: $2.4 billion
36. Winnipeg North End Treatment Plant upgrade, Manitoba: $2.3 billion
37. Vancouver New St. Paul's Hospital, BC: $2.3 billion
38. Vancouver Northwest Langley Wastewater Treatment Plant, BC: $2.3 billion
39. Montreal Île-aux-Tourtes Bridge reconstruction, Quebec: $2.3 billion
40. Toronto Gardiner Expressway rehabilitation plan, Ontario: $2.2 billion