Le Phuoc Thanh, head of the National Assembly delegation from Quang Nam, told the conference named "Sustainable Development of Hydro-power Projects: Lessons and Warnings" that dams have destroyed forests, caused floods in the lower sections of rivers, and swallowed a lot of arable land.
Investors, and not common people, benefit mostly from them, he added.
Dinh Van Thu, deputy chairman of the Quang Nam People's Committee, said: "We made a big mistake by allowing the development of so many hydro-power projects. It is a little bit late to correct the fault."
Prof Vu Trong Hong, chairman of the Viet Nam Irrigation Association, said some 800 medium and small dams are blocking off and "killing" all the country's rivers, especially in the central and Central Highlands regions.
He laid the blame squarely on the privatisation of power generation for the massive investment in hydro-power projects.
"BOT (build-operate-transfer) investment in hydro-power projects is banned in other countries but allowed in Viet Nam," he said.
Dr Dao Trong Hung of the Viet Nam River Network (VRN) said around 16 hectares of forests need to be destroyed to generate a megawatt of hydropower.
"They were ‘forest destruction' projects that were licensed in the name of hydro-power projects," he said.
Dams have also affected bio-diversity, he said, pointing out that 110 hydro-power projects are encroaching on 47 forests. The Cat Tien and Hoang Lien National Parks were alone home to 12 of them, he said.
People relocated to make way for dams too suffered he said, referring to the 1968 Thac Ba Hydro-power Plant which uprooted many who continue to lead a hand-to-mouth existence after all these decades.
Irrigation expert Le Tri Tap, who is also an ex-chairman of the Quang Nam People's Committee, said dam projects ignore sustainable resettlement of residents relocated to build them.
"That is how these hydro-power projects have impoverished people."
Authorities failed to carefully identify the adverse impacts of dams while investors had unscrupulously tried to alter the basins of rivers, causing a long-term threat to the environment, he said.
Do Tai, chairman of the province's Dong Giang District which has seven hydro-power projects, said: "I was heartbroken to see many residents in my district losing their land to hydro-power projects. They were forced to destroy forests to earn a living and were later prosecuted for [it]."
VRN urged relevant authorities to consider each dam project carefully before licensing.
Their benefits should be shared with residents and communities affected by them, VRN said.
Though invitations had been sent to hydro-power investors across the country, none attended the seminar which was organised by the Quang Nam NA delegation and VRN.
Just a few days ago the Ministry of Natural Resources and Environment announced inspections of hydro-power projects in 22 provinces and cities.
They will be examined for land, environment, water-resource, and hydrometeorology issues.
Last year the Department of Industry and Trade of Quang Nam Province had urged Quang Nam and the Ministry of Industry and Trade to scrap six long-delayed, environmentally harmful dam projects.
Ngoc Tuan