The world's big digs

Massive construction projects are planned or underway around the world. Consider China's $63-billion — yes, billion — water diversion project, or Canada's own ambitious plans for the 2010 Winter Olympics.

Tallest building, artificial rivers among the boldest, most expensive projects

Members of the tunnel construction crew watch a boring machine emerge from the ground, completing the second and final tunnel for the Canada Line in Vancouver, March 2, 2008. The transit line will serve as a crucial transportation link for the 2010 Winter Olympics. (Richard Lam/Canadian Press)

Construction on Montreal's Honoré Mercier Bridge, billed as Canada's largest bridge repair, has a price tag of $66 million for its first phase. Work is expected to last until 2011.

It's a big endeavour, to be sure. But it still pales in comparison to the scope of massive projects planned or underway around the world. Consider China's $63-billion — yes, billion — water diversion project, or Canada's own ambitious plans for the 2010 Winter Olympics.

Many of these projects break new ground, figuratively as well as literally, in striving to set new world standards. They want to be tallest, widest, first or most expensive works of their kind.

Some of the world's biggest digs, either underway or planned, follow below. It's not an exclusive list, so post your suggestions, too.

China: North-south water diversion

A labourer works at the construction site of a water diversion project on the outskirts of Beijing in February 2008. (Guang Niu/Getty Images)

Estimated cost: $63 billion

With this massive hydro-engineering plan, China seeks to deliver water from the water-rich Yangtze River area in the south to parched regions in the country's north and west. In essence, the Chinese want to build a series of new, artificial rivers.

Adopted in 2002, the ambitious plan calls for three water routes to eventually be built. Planners hope that the 1,250-km central and 1,150-km eastern routes will divert 13 billion cubic metres of water to Beijing and other northern cities by 2010.

Due for completion in 2050, the western route cuts through the mountains of Tibet to reach China's arid northwestern provinces.

If completed as planned, all three routes would carry a torrent of water as powerful as the flow of the Yellow River, China's second-longest waterway. The key word is "planned": Parts of the project have been delayed by technological and financial difficulties and concerns over water pollution, state media has reported.

Vancouver: 2010 Olympic infrastructure

Snow-capped mountains serve as the backdrop for construction workers building the Canada Line at Vancouver's international airport in Richmond, B.C., on March 1, 2008. (Jonathan Hayward/Canadian Press)

Estimated cost: $2.6 billion

Two major projects are transforming transportation in British Columbia's Lower Mainland in the lead-up to the 2010 Winter Olympics.

The 80-kilometre Sea to Sky highway, from Vancouver to the resort town of Whistler, is being improved  at an estimated cost of $600 million. New passing lanes are being added and some sections straightened to improve safety.

The new Canada Line, meanwhile, will provide a 19.5-km rail link between Vancouver and the city's international airport in Richmond. Completion of the 16-stop line is expected in 2009 in advance of the beginning of the Games.

Panama: Panama Canal expansion

Estimated cost: $5.25 billion

Workers use heavy machinery at the site of the Panama Canal expansion project in Panama City on April 28, 2008. (Arnulfo Franco/Associated Press)

Approved in a 2006 national referendum, this project will be the largest improvement in the historic waterway's history.

The canal's locks will be widened by 17 metres to 50 metres to accommodate modern ocean-faring vessels. By the time of its expected wrap-up in 2014, officials expect the canal's shipping capacity will be doubled.

That will be good news for the ships who make the 14,000 annual trips through the 82-km-long canal. The smaller waterway has forced costly queues in recent years.

If finished as planned in 2014, the expansion will open at the same time as the Panama Canal's 100th anniversary. It was originally built by the Americans and French and transferred to full Panamanian control in 1999.

United Arab Emirates: Burj Dubai

The Burj Dubai tower, still under construction, rises above the skyline of Dubai, United Arab Emirates, in November 2007. (Nousha Salimi/Associated Press)

Estimated cost: $4 billion

With their ultra-tall Burj Dubai, Emaar Properties want to do more than part the clouds with their building. The developers want to make a statement. A big statement.

Even while still under construction, the Burj Dubai is already the world's tallest free-standing structure, eclipsing Toronto's 553-metre-tall CN Tower  in September 2007.

When completed in late 2009, the building will exceed 800 metres and house offices, a glitzy hotel and residential space.

By then, the skyscraper will have consumed 330,000 metric tonnes of concrete, 39,000 metric tonnes of steel rebar and 142,000 square metres of glass, and 22 million worker hours of labour.

Algeria: East-west highway

A man walks past a bridge under construction about 150 km east of Algiers in May 2006 as part of the Algerian east-west highway project. (Fayez Nureldine/AFP/Getty Images)

Estimated cost: $13 billion

Flush with a windfall of oil and gas revenues, the Algerian government has embarked on a $144-billion project to upgrade the country's public works. Schools, hospitals and a subway for the capital, Algiers, are all being built.

A cornerstone will be the east-west highway that will span more than 1,200 km across the country, connecting the Tunisian border in the east with Morocco in the west.

Expected to be completed in 2010 and financed completely by the government, the roadway will also connect Algiers and other major cities in the country's north.

China: Three Gorges Dam

Three Gorges dam, part of the massive hydropower project under construction on China's Yangtze River, is seen from a distance in May 2006. (Du Huaju/Xinhua/Associated Press)

Estimated cost: $25 billion

Spanning the Yangtze River, Three Gorges is 210 metres high and more than two kilometres long. Critics call it an environmental nightmare, but China's leaders believe it will control flooding along the Yangtze, harnessing an estimated 18,000 megawatts of power by its eventual completion in 2009.

However, the dam has displaced more than one million people and it's estimated rising waters will submerge 1,200 towns and villages.

Work began in 1993 on the project which, when complete, will produce three times the capacity of Canada's Churchill Falls generating station in Newfoundland and Labrador.

Moscow: Crystal Island

Estimated cost: $4 billion

Once completed, this sprawling residential and commercial complex near the heart of Moscow is expected to be one of the world's largest and most expensive buildings.

British architect Norman Foster has drafted plans for a tent-like structure with 2.5 million square metres of ground space set around a 450-metre peak.

As planned, Crystal Island would include an observatory deck near the top, as well as apartments, entertainment facilities and sports complexes.

San Francisco: Bay Bridge repairs

The San Francisco-Oakland Bay Bridge sits closed for the 2007 Labour Day weekend as construction crews replace a 350-foot stretch of the bridge. (Noah Berger/Associated Press/Metropolitan Transportation Commission)

Estimated cost:$6.3 billion

Upon its completion in 1936, the Bay Bridge was hailed as an engineering triumph, spanning the 13 kilometres between San Francisco and Oakland, Calif.

But a major 1989 earthquake, which caused extensive damage to the bridge, drove home the need for repairs to guard against future temblors.

So this massive repair project  was drawn up. The eastern span will be entirely rebuilt and its western portions greatly overhauled.

Work on the bridge, which carries an estimated 280,000 cars per day, is expected to wrap up in 2013.

Australia: Brisbane bypass tunnel

Estimated cost: $3 billion

This big dig will eventually deliver Australia's largest tunnel, built under the streets of the city of Brisbane. Named the Clem Jones Tunnel after a popular former mayor, it will provide another north-south traffic artery through the city.

The goal for completion is the end of 2009.

Italy: Strait of Messina Bridge

People march with a mock bridge built on a coffin near in Rome during a September 2006 protest demanding the government revive plans to build a bridge connecting Sicily with mainland Italy. The new government of Silvio Berlusconi, elected in April 2008, has pledged to restart the project. (Riccardo De Luca/Associated Press)

Estimated cost: $9 billion

Since Roman times, Italian leaders have dreamed of a fixed link between the mainland and the island of Sicily. Prime Minister Silvio Berlusconi tried to bring such a plan to life after his election in 2001, only to have it scuppered after a change of government in 2006.

The April 2008 election restored Berlusconi to power and gave the idea a second life.

The new plan calls for a 3.3-kilometre suspension bridge — it would be the world's longest, besting the current world record holder by almost 1.5 kilometres. Construction could begin in 2010 and wrap up by 2016, a government official says.

Las Vegas: CityCenter

Construction workers take a look at the Vdara tower at CityCenter in Las Vegas, May 8, 2008. The tower was the first at the multi-billion dollar casino hotel and condo project to be topped-off. (Isaac Brekken/Associated Press)

Estimated cost: $9 billion

Dubbed a "city within a city" on the famous Las Vegas Strip, this monster complex  will combine a resort casino called Aria, along with several other hotels and residential buildings.

CityCenter will cover 76 acres after its expected completion in 2009. A little more than 46,000 square metres of space will be dedicated to The Crystals, a complex featuring restaurants, retail and other entertainment.

The project will employ about 7,000 construction workers, according to the developers.