HOA BINH, Vietnam -- As recently as two years ago, the Vietnamese capital of Hanoi suffered the daily ignominy of crippling power shortages that hobbled industry and left residents to sit in the dark most nights.

The power outages are now just a distant memory, thanks to a massive $1 billion dam in Hoa Binh -- a two-hour drive southwest of the capital -- that was built by an army of 30,000 workers guided by 1,000 experts from the former Soviet Union.

The 40-story-high Hoa Binh dam is the largest hydroelectric project in Southeast Asia and will produce a staggering 1,900 megawatts when the work is completed. It is also the largest industrial project ever undertaken in Vietnam, the last showpiece of Soviet aid before the collapse of communism brought an abrupt end to Moscow's overseas largess.

But in order to power the dam, authorities flooded some of the richest rice land in northern Vietnam to create a 75-square-mile reservoir. Upwards of 50,000 people were moved from their fertile valley farms to mountain villages and left to fend for themselves.

Today, more than four years after they were resettled, the farmers eke out a pathetic living trying to grow cassava and tea on precipitous mountainsides. Many have resorted to eating tree bark or roots -- and have caused calamitous deforestation around the lake as a result. Ironically, none of the resettled families has yet to receive any electricity.

"We can't feed our children anymore," said Dinh Van Thien, 58, a father of 10 who was once a relatively prosperous rice farmer. "We don't have a stable life here. We are hungry. We are very hungry."

Hoa Binh, rather than becoming the symbol of progress that its designers in Moscow once envisaged, has become a cautionary tale debated throughout Asia at a time when many countries in the region are considering investing massively in hydroelectric projects to meet their burgeoning energy needs. For most of these countries, electricity is the life blood fueling booming export-based industrial economies, and their power needs are expanding at a dizzying rate.

Advocates view hydroelectric power as a clean, renewable resource preferable to virtually any other form of electricity generation.

But critics maintain that the huge dams involved in hydroelectric energy generation are destroying the last wilderness areas of Asia at a time when trees and arable land are in ever shorter supply. In essence, they say, the dams are robbing the rural poor to provide power to the urban rich.

Environmental groups and organizations representing rural farmers have managed to attract public attention to their cause in countries such as India and Thailand. It is the first time that such groups are being heard in the developing countries of Asia, which in the past have prized economic growth above all.

In India, opposition forces have mobilized to block the Sardar Sarovar dam, the first of a planned 30 dams being built across the Narmada River at an estimated cost of $9 billion.

In Thailand, a committee of countries along the famed Mekong River is proposing the construction of a $2.7 billion hydroelectric project between Laos and Thailand. Plans for the dam, called Pa Mong, have been drastically scaled down to reduce the number of people resettled to about 50,000 from the earlier planned 350,000 -- a level the designers now admit was "unrealistic."

"I don't think these countries can afford to ignore the tremendous generating capacity of the seventh largest river in the world," said Charles Lankester, a Canadian and former U.N. official who now heads the Mekong Committee, which is operated by Thailand, Laos and Vietnam. "It's a huge resource. Once the environmentalists look at some alternative sources, the feasibility of hydro will re-emerge."

The decision to press ahead with Pa Mong followed a decision by the World Bank in December to go ahead with funding for the Pak Mun dam being built near the Cambodian border by Thailand's Electricity Generating Authority, using World Bank funding.

In Indonesia, 600 families last year staged a rare protest against the government's seizure of their lands to build a dam in central Java. "Development requires sacrifice," President Suharto told the demonstrators, who were demanding increased compensation for their land.

China also is planning major hydroelectric projects, including the world's third largest dam along the Yalong River for the country's Sichuan province. And Malaysia has a huge hydroelectric project on the drawing board.

Apart from desperately needed power generation, Vietnam's Hoa Binh dam was designed to regulate the flow of water reaching the Red River, to control flooding in the wet season and provide irrigation during the dry months.

But although the major goals were achieved, Nguyen Van Linh, who until last year headed the Communist Party in Vietnam, publicly criticized the country's electric authorities for the treatment of the largely minority tribesmen who had lived in the area of the reservoir. The poor treatment of the minorities, mainly Dao and Moung, also was the centerpiece of a Hanoi television expose.

"Big social problems were created for the minorities," said Le Hong Tam, an economist at Hanoi's National Center for Social Sciences. "The people in the reservoir area have suffered very much."

The majority of farmers, who were used to harvesting two crops a year of rice, were never provided with alternate means to earn a living or feed their families. For example, while the reservoir is said to be rich in fish, the farmers were never trained in fishing or given boats and nets to do the job.

The biggest problem, according to authorities, was that the farmers started clearing the land of the trees, to sell or burn the firewood, build houses and make room for their crops.

The lack of trees causes dirt to run off into the reservoir during rainy months, and this in turn has created enormous silting problems. According to one report, the life span of the dam may have been reduced from 200 years to 50 years by the silt problem.

Thai Phung Ne, an adviser to the minister of energy, conceded in an interview that planners had erred in the resettlement program by not building housing and other facilities for the farmers sooner.

But he steadfastly maintained that the decision to proceed with the huge dam was "correct" and said Vietnam is going ahead with plans for a project twice as big as Hoa Binh further north. Western diplomats said they doubt the country will ever find the financing.

Hoa Binh itself is only half completed, with four turbines in place, two ready to be installed and two more on order from a factory in St. Petersburg. Northern Vietnam already has a surplus of electricity, even with only four turbines working, while south Vietnam still endures daily shortages.