International dambuilders were stunned in 1997 by the World Bank's brokering of a worldwide $10-million effort to provide the first "holistic" review of the megaprojects. Now, they are bracing for release of a report that could rewrite planning and, more importantly, lending criteria for large international dam projects.

PROBLEMS Three Gorges Dam reported its first fatality, but other large dams face new scrutiny of costs, impacts.(Photo by Andy Ryan)

Over 300 members of the International Commission on Large Dams (ICOLD) met last week in Beijing, China, to formulate a strategy to smooth acceptance of large dams, at least 50 meters high. A succession of speakers referred to the "critical times" now facing dambuilders.

IMPACTS.
WANG JIAZHOU
(Photo by Andy Ryan)

"We will be saying that social and economic impacts are undeniable," WCD Commissioner Judy Henderson told ICOLD members. "Indeed, many are now regarded as unacceptable. But we also say they are not necessarily inevitable. Given today's knowledge and experience, many are avoidable."

Topics of particular concern for the industry are resettlement and compensation for people directly affected by large projects and environmental impacts upstream and downstream. Many large dams being built in developing countries have been harshly criticized for ignoring or paying scant attention to such issues.

"Our concern is that criteria will be so strict so as to prohibit developing nations from obtaining financing," said ICOLD President Kaare Høeg, of the Norwegian Geotechnical Institute. That could severely impact many of the world's planned large dams, particularly in developing nations. China, Indonesia and Thailand have received almost 20% of all global aid for hydroelectric projects over the past 20 years, according to London-based WDC India has 18 projects under construction and another 20 in planning stages.

The issue has forced Høeg to adjust ICOLD's agenda over the past year to ensure that WCD commissioners and staff are aware of industry best practices and standards. ICOLD members worry over what they perceive as an anti-dam bias among WCD staff. Høeg's emphasis in actively disseminating the organization's papers was meant to counter that bias. "Ecological balance is a relative term, not an absolute," he noted.

Henderson says WCD drew heavily on ICOLD research. Its positions on the environment and socioeconomic impact are progressive and "frankly, go further than what we can recommend," she says. Henderson also touched on overruns "associated with downstream impacts that are often significant...and often unanticipated and thus not compensated for." And compliance with resettlement policies often is not carried out.

RALLYING CRY.

About 125,000 people will be moved out of the area altogether because of government policy prohibiting development of steep, unfertile slopes around the Three Gorges reservoir. Chinese designers say Three Gorges will efficiently pass silt and sediment from the Yangtze River through a series of outlets at the 90-m elevation of the 181-m-high dam. But erosion of reservoir slopes could increase the sediment load enough to cause problems. "Moving 1.1 million people is a most troublesome task," said Lu You Mei, Three Gorges Development Corp. president. "It is more difficult to remove people than to build Three Gorges Dam itself."

DELAYS?
LU YOU MEI
(Photo by Andy Ryan)

Three Gorges Vice President Wang Jiazhou says an investigation by Chinese authorities continues into the accident that killed three workers and injured 30. The accident occurred when workers repairing a tower-belt crane purchased from Elmhurst, Ill.-based Rotec Industries dropped some parts from a conveyor. The pieces fell 60 ft, hitting the workers below.

Rotec Chairman Robert F. Oury terms the accident "devastating," but declines to elaborate on possible causes while the investigation continues. He notes, however, that the crane "was under the control" of Chinese concrete subcontractor Gezhouba. Oury told ENR that the accident has shut down all six tower-belt cranes at the site, and he does not know when they would be allowed to restart. He notes they had been operating incident-free for the last 14 months.

KEEP COOL.

At the shiplock, designers and contractors worried over the stability of the locks' high slopes. Side high wall slopes have a maximum height of 170 m, excavated from hard rock. The largest locks in the world, the five-step system has a total length of 1,607 m. A 60-m-wide rock ledge separates the downstream from upstream channel. Walls are being lined with thin concrete, so engineers were concerned about stability in excavated bedrock. Wang says the contractor installed prestressed tendons and high-strength rock bolts to stabilize the area.

LOOKING AHEAD.

Despite ICOLD's apprehension over the future of large dams, Høeg and others think they can move forward. He says the commission has already called for more comprehensive planning and participation by new constituencies. But neither ICOLD guidelines nor WDC recommendations are enforceable, and individual governments may choose to ignore them.

WDC's influence with lending agencies could be a key factor. "You've got to get the whole package right in terms of social and environmental factors" said Henderson. "You can take this as a threat to the way things have been done or as an opportunity to move forward."

Their focus was on the World Commission on Dams (WCD), whose report on costs and benefits could redefine methods and practices for moving large dams into actual construction. The report, to be released in November, will emphasize socioeconomic and environmental consequences of large projects—defined not only by governmental planning agencies, but also by citizen and other activist groups not traditionally included in planning efforts. Resettlement has been a key issue for opponents of China's $24-billion Three Gorges Dam, the world's largest construction project. Guo Shuyan, deputy director of the State Council's Three Gorges Dam Project Construction Committee, said 1.1 million people will be resettled by the time the project is finished in 2009, at a total cost of $22 billion. That includes funds to build new housing and infrastructure in relocation areas. Chinese contractors continue to keep to their aggressive schedule, placing a record-shattering 553,500 cu m of concrete in one month for the dam's spillway, intakes and powerhouse. But a fatal accident Sept. 3, the first reported on the project, could affect some work. Wang reported that two of the project's most perplexing problems have been solved. A strict quality control program to consistently produce concrete at a constant 7°C is working. Aggregate in each of the project's nine batch plants is cooled with minus 5°C air, and then mixed with ice. A high-speed system of cranes and conveyors delivers the mix quickly, and cooling pipes installed in monolithic blocks as large as 1,000 cu m keep heat down during curing. The concrete-gravity Three Gorges Dam will eventually stretch 2,309 m to impound the Yangtze and create a long, thin reservoir that can store 39.3 billion cu m of water. The project's size and cost makes it a lightning rod as China pursues an ambitious plan to build 120 large dams over the next 20 years.