Dams the cause of flooding in the Northeast, academic claims

MAHA SARAKHAM – Floods caused by heavy rain hammering the Northeast in late July killed 29 people and caused damage of an estimated ten billion baht (about $300 million.)

On 25 July, tropical storm Sonca whipped through northeastern Thailand causing flooding in several provinces. In Nakhon Phanom Province, over 3,000 households were submerged by floodwaters. The water level in the streets of Sakon Nakhon City rose to 70-80 cm, leaving several main roads impassable.

The severity of the flooding this year, though, might be avoidable. Mahasarakham University lecturer and environmental activist Chainarong Sretthachau argues the problem is linked to the state’s water management of recent decades, especially the construction of dikes and dams, and the destruction of wetlands.

Chainarong Sretthachau, a lecturer at Mahasarakham University’s Faculty of Humanities and Social Science, is also an environmental activist and former director of the Southeast Asian Rivers Network.

Dikes undermine nature’s flood control

Mr. Chainarong explains that the construction of dikes has damaged the natural drainage of floodwaters. Most dikes in the region were built as part of the Khong-Chi-Mun Irrigation Project, an unfinished state-sponsored development project that aimed to extend irrigated agriculture to the Northeast.

The dikes are usually located along rivers banks, cutting off nearby forests from absorbing excess water. Naturally, these forests help reduce the damaging effects of flooding and stabilize the banks. Riparian areas also dissipate stream energy and naturally slow the flow of the water. With dikes in place, the flow of water accelerates, increasing the chance of flash floods.

Constructing dams, destructing wetlands

Several dams located upstream of the region’s rivers, like the Ubol Ratana Dam, Lam Pao Dam, Nam Pung Dam and Lamtakhong Dam, are prone to causing massive floods if not maintained correctly and regularly monitored, says Mr. Chainarong.

Dams located in low-lying areas have often submerged wetlands which are important areas of biological diversity, explains Mr. Chainarong. Wetlands also function as critical drainage areas in the Northeast, absorbing excessive water in the rainy season. For example, the controversial Rasi Salai Dam in Sisaket Province led to the most extensive destruction of wetlands in southern Isaan.

Wetlands are also at threat by expansion of large cities in the region. In Warin Chamrap District, a suburban area of Ubon Ratchathani City, wetlands have had to make way for urban development projects.

Proposing a solution

Mr. Chainarong thinks it should be the government acting to reduce the effects caused by state water-management projects in the Northeast. He proposes measures to alleviate problems caused by dams and to restore the region’s wetlands

“A first, immediate solution to the problem is to stop large dams from discharging water, and open all floodgates so that water masses that are trapped behind the gates can flow on,” Mr Chainarong says, adding that all barriers that obstruct the flow of water should be removed.

Dams in the Northeast have tended to “punish” the region instead of producing any benefits, Mr. Chainarong says. He raises the example of the Pak Mun Dam in Ubon Ratchathani Province, which stayed far behind its projected electricity output.

Citing positive examples of the USA and countries in Europe where many dams have been removed or stopped operating, Mr. Chainarong calls on the Thai government to adopt environmentally sound water-management approaches and supports the restoration of wetlands.

Mr. Chainarong believes that shutting down the operations of all dams, without demolishing them, will in the long-run save the region from severe floods.

Reporting by Danuchat Boon-aran, a participant of The Isaan Journalism Workshop 2017 organized by The Isaan Record.