Dams and Landslides

Monuments of the millennium

Philippine Daily Inquirer
October 12, 1999

Benguet, Philippines–ASIA’S monuments for the start of the next millennium will not be tall towers or staggering statues but giant hydroelectric dams.

In China, the Three Gorges, the world’s biggest dam, is being built across the Yangtze River. It is the largest concrete structure on earth.

Astronauts reported seeing the Great Wall of China when they walked in space. They would be blind not to see the Three Gorges dam and its 400-mile long reservoir.

India has been building the Sardar Samovar dam, more known as the Narmada dam, since 1979. It cannot be ascertained how much power or how big the reservoir of the Narmada would be because of the huge controversy it has raised.

The decision in February by India’s Supreme Court to increase the dam wall by 5 meters (from the original 63 meters) was opposed by the people because it would mean the dislocation of 3,000 more families.

More than a million residents were already dislocated by the dam. The fight against the Narmada dam has spawned an opposition army called the ”Narmada Bachao Andolan” (Save the Narmada), which is composed of hundreds of affected residents and urban-based activists.

Compared to the Three Gorges and the Narmada dams, the San Roque multipurpose dam being built in the boundary of San Manuel, Pangasinan, and Itogon, Benguet, is no small dike.

At 200 meters, it is the tallest dam in Asia. Set to generate 345 megawatts of power, it will also be the largest private hydropower project in Asia.

Since the $1.19-billion funding for the San Roque dam has already been assured, there will be no doubt that the dam will be completed by 2004 as scheduled.

Era of big dams

”Big dams haven’t really lived up to their role as the monuments of modern civilization, emblem of man’s ascendancy over nature. Monuments are supposed to be timeless, but dams have an all-too-finite lifetime. They last only as long as it takes nature to fill them with silt,” Arundhati Roy wrote in her essay titled ”The Greater Common Good” written for The Hindu.

Roy, the 1998 Booker Prize winner for her first novel God of Small Things, went to Narmada recently before the valley would be flooded in the next monsoon.

”There was a time when big dams drove men to poetry. Not any longer. All over the world, there is a movement against big dams,” she said.

In the United States, for example, the government is decommissioning dams, blasting silted dams to revive rivers.

Roy likened the battle of Narmada dam as a ”Nehru versus Gandhi” argument.

”[Jawaharlal] Nehru and [Mohandas] Gandhi were generous men. Their paradigms for development are based on assumptions of inherent morality. Nehru’s on the paternal, protective morality of the Soviet-style Centralized State. Gandhi’s on the nurturing, maternal morality of romanticised village Republics. Both would work perfectly, if only we were better human beings,” she said.

We, unfortunately, are not. Who would be the Nehru of San Roque?

It would be former President Fidel V. Ramos who has campaigned for the construction of the San Roque dam throughout his term. He said the dam would be a blessing for agriculture because it would irrigate 87,000 hectares of farmland in Pangasinan and Nueva Ecija.

It would also stop the flooding in the region, Ramos promised.

It would be frivolous to compare Gandhi to Pascual Pocding, head of the Santahnay Shalupirip Indigenous Peoples Movement in Itogon. Pocding even went to Japan to campaign against the San Roque dam project to stop the inundation of his hometown.

Pocding and his ancestors have been planting rice by the mountainside and living a romanticized life without government intervention.

Now the government has come to Pocding’s Shalupirip village in the form of the dam. He said he would rather die than relocate.

Roy noted that the majority of those affected by the dams in India (there are 3,600 dams in the subcontinent) were indigenous peoples.

She said 60 percent of all the affected Indian residents belonged to indigenous groups, which only comprised less than 10 percent of all Indian peoples.

Five of the major dams in the Philippines are situated in the Cordillera and three lie across the Agno River.

The Ibaloys, who were dislocated in the 1950s due to the construction of Ambuklao and Binga dams in Bokod, Benguet, went to Nueva Vizcaya and Apayao.

Unfortunately, the Casecnan trans-basin dam and the Abulug dam will be built in Nueva Vizcaya and Apayao, respectively.

”We feel we are being followed by standing water,” said one of the transplanted Ibaloys in the Casecnan site.

It’s not only a matter of the trampling of indigenous people’s rights.

Dams are a way of accumulating authority, as Roy said, because the government decides who gets water and who doesn’t.

In the 40 years that the Ambuklao dam was constructed, it was only recently that the residents there were energized.

Irrigation and flood control were the catchwords for San Roque, which was why the majority of Pangasinan officials approved the dam.

Three Gorges dam

But if government officials look at the history of dams in China, they better think again.

In the 1950s, China built a network of 62 dams along the Yangtze (where the Three Gorges dam is located).

Things worked out fine until Aug. 4, 1975 when it began to rain heavily. ”The rain turned into a typhoon, which caused a flood,” wrote Elizabeth Gilbert in her article for Spin magazine on the Three Gorges.

”On the night of Aug. 7, all 62 beautiful new dams broke, one after another. They let loose in a fast row, like buttons on the Incredible Hulk’s shirt–Pop! Pop! Pop! Pop!–all the way down the river.”

The last to fall was a dam called Banqiao, which was described as indestructible.

Tens of thousands of people died because of the collapse of the dams and a hundred thousands more died because of the resulting famine and disease.

The Three Gorges dam showed that China refused to learn its lesson.

”It will submerge 800 ancient sites, including temples and unexcavated archeological ruins. It will destroy seven counties and 770 villages. Before the estimated $40-billion project is finished, nearly 1.5 million Chinese citizens will have been involuntarily or forcibly relocated from their homes,” Gilbert wrote.

The government insisted no such thing would happen to San Roque despite the fact that the Ambuklao and Binga dams are situated upriver.

Director Raymundo Punongbayan of the Philippine Institute of Volcanology and Seismology said the San Roque dam could withstand a major earthquake caused by the movement of the nearby Digdig and San Manuel Faults.

He said the Ambuklao and Binga dams survived the 1990 earthquake and did not collapse. Pantabangan Dam, which is only 8 kilometers from Digdig Fault, also survived the quake.

But the effect of the 1990 earthquake would harm San Roque, a noted American scientist said.

According to Tiziano Grifoni, a civil engineer and geotechnical consultant for many large dams around the world, the 1990 earthquake has weakened the rock formation of the dam site of San Roque.

”The strong ground shaking developed by the 1990 earthquake could . . . have weakened the rock formation at the dam site. Weakened rock conditions could lead to massive landslides. Large landslides occurring upstream of the dam into the reservoir could generate waves capable of overtopping the dam,” Grifoni said.

He said seiche hazard should have been considered for the dam design. Seiche are earthquake-induced waves that match the natural period of oscillation of the reservoir.

”A 7.8 earthquake similar to that which occurred in 1990 in Luzon could last up to 90 seconds. Seiche waves could reach several meters in height and could increase erosion of banks and upstream slope of the dam,” Grifoni said.

Flood control

If earthquakes are not the problem, flooding will be one.

Last month, several Pangasinan residents sued the National Power Corp. for the floods in Pangasinan caused by the release of water from the Binga and Ambuklao dams.

The complainants, who are asking for P25 million in damages, said the unannounced and sudden discharge of water from these dams caused huge damage to the province.

Peter Willing, a hydrologic engineer of the University of Washington and lead consultant of Water Resources Consulting, said the San Roque dam could not contain severe flooding.

Because the San Roque dam is above all a power plant, it would always be filled at full capacity and not emptied in preparation for a flood.

”Building a dam that will contain the five-year flood is asking those below the dam to develop a false sense of security, which will result in increasingly damage-prone uses of the floodplain, and far more devastating floods when the five-year magnitude does occur,” Willing said.

But a five-year flood is more or less regular. How can San Roque contain the so-called ”hundred-year flood” which occurred in Ormoc in 1991?

”There is about a three-hour travel time for a flood to move from Binga to the populated areas downstream; it will be less for San Roque. There is no mention of how residents downstream are supposed to respond to a flood warning,” Willing said.

He said the mine tailings dam of mining corporations upstream could worsen the flooding. It could cause an overtopping of the dam if one of these large mine tailings dam breaks.

And because the mining firms empty their discharge along the Agno River, the flood will also be potentially toxic.

Robert Moran of the University of Texas in Austin, who is a consultant for water quality testing of natural and contaminated resources in many countries, said the reservoir water was possibly laden with cyanide and was slightly radioactive.

He said rocks associated with gold and copper ores in the region contain elevated radioactivity. He also dismissed findings of the 1997 environmental impact assessment (EIA) of San Roque dam that no cyanide forms could be found in the region.

”Many cyanide forms commonly found at mining sites, such as numerous metal-cyanide complexes, thiocyanate, cyanate, etc., do persist, and are toxic to aquatic organisms,” Moran wrote.

Much of mining water collected were alkaline but this ”does not mean that these mine wastes cannot become acid in the future,” he said.

Will there be a future for big dams?

India, while awaiting the construction of the Narmada dam, has developed its wind energy. It is now the second largest producer of wind energy in the world.

China is also pushing toward ”clean energy.”

The Philippines, despite a typhoon country, has only one 10-kilowatt wind turbine in Pagudpud, Ilocos Norte, to be proud of. Most of its new power plants are gas-powered and still rely on petroleum imports.

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