Civic groups on Sunday lodged a petition calling for governments of countries along the Mekong River to review upcoming dam projects.
The petition was on Sunday submitted to the National Human Rights Commission (NHRC) by the Mekong Conservation Network in the North during a forum held in Chiang Rai province on the effect of dams on the Mekong River.
Mekong Conservation Network coordinator Somkiat Khuanchiangsa said China, Myanmar, Laos, Thailand, Vietnam and Cambodia must find a solution to contain ecological damage already caused by 11 operational dams and another 11 to be built on the lower Mekong.
"Problems have already occurred and that proves that development of hydro-dams on the Mekong River is problematic," Mr Somkiat said. "If governments of these countries can solve these setbacks, the case of Mekong River management will become a model for the world on sustainable development."
The dams already built on the lower stretch of the Mekong River are mostly in China and Laos, with those still to be built mostly set for Laos and Cambodia.
Pianporn Deetes, a conservationist representing the International Rivers campaign group, said a drastic drop in water levels and the ensuing ecological impact such as drought and fish extinction in the Mekong River "will become normal" if a series of hydro-dams such as Xayaburi dam start operating in the next three decades.
Ms Pianporn urged governments in riparian countries and dam operators to come up with preventive measures and mitigation plans.
"The operator of Jinghong dam in China needs to analyse the water volume in the Mekong and tributaries before regulating any flow and must do it carefully because the dam is only 360km from Chiang Rai province," she said.
For Xayaburi dam in Laos, in which Thai construction firm CH Karnchang is a co-investor and will sell electricity to the Electricity Generating Authority of Thailand (Egat) after October, Ms Pianporn said the operator should conduct a test run only when there is sufficient water volume in the Mekong.
"Egat must realise that water in the Mekong is scarce ... fish in the river will be gradually wiped out," she said.