Story | 01 Jul, 2015

Benefits of Mae Wong Dam unlikely to outweigh environmental costs, IUCN report says

A new IUCN report suggests that the construction of a dam within Mae Wong National Park may negatively impact both the integrity and 'Outstanding Universal Value' of the Thungyai-Huai Kha Khaeng Wildlife Sanctuaries, Thailand’s first Natural World Heritage Site. Habitat destruction and increased poaching in Mae Wong National Park related to dam construction would be likely eventually to 'spill over' into the World Heritage property, impacting its Outstanding Universal Value.

A dam on the Mae Wong River has been proposed multiple times over the past 20 years, and each proposal has been met with criticism from a variety of sources. Early proposals for a Mae Wong Dam focused on its role as an irrigation tool to provide water to cultivated land during the dry season. Later on, proponents described the dam as a flood-control mechanism, to assist with flood prevention on the central plain of Thailand.
 
The proposed dam would be located in Mae Wong National Park in the country’s Western Forest Complex and adjacent to the Thungyai-Huai Kha Khaeng Wildlife Sanctuaries World Heritage Site. The Western Forest Complex is one of the most important remaining tracts of relatively intact forest in Southeast Asia, of global importance for biodiversity and the second most important tiger landscape in the world.

The IUCN report, commissioned by IUCN’s Thailand National Committee, was based on desk-top review of available information and interviews with experts. It is intended to provide an independent scientific assessment addressing concerns around possible impacts of the proposed Mae Wong dam - including the ecological value of the proposed dam site, the ongoing discussion over the dam’s intended use as an irrigation or flood-prevention tool, and potential alternative mechanisms for water management in Thailand.

The report concludes that based on available information it seems unlikely that the irrigation and flood prevention benefits of the dam will be sufficient to justify the scale of the investment proposed or the environmental cost to be incurred. The report further recommends that as a priority, additional assessments should be undertaken of the proposed dam and the alternative water management options available.

“We hope that this report will be useful in informing the decision-making process around the proposed dam,”
says IUCN Southeast Asia Head, Robert Mather. “Thailand currently has two Natural World Heritage Sites which make an important contribution to the economy through tourism and to protection of biodiversity, and are also a major source of pride for the Thai people. One additional site has already been proposed (the Kaeng Krachan Forest Complex), and another site in the Andaman Sea is expected to be proposed in the near future.”

Thailand’s Western Forest Complex

Thailand’s Western Forest Complex (WEFCOM), the largest protected area complex in Thailand (about 18,000km2), is made up of 17 contiguous protected areas (six wildlife sanctuaries and 11 national parks). With forest cover nearing 80%, and habitat continuous with intact forests in Myanmar, this area is one of the most important remaining tracts of relatively intact forest in Southeast Asia, of global importance for biodiversity and is the second most important tiger landscape in the world. In 1991, three large protected areas comprising the core area of WEFCOM (Huai Kha Kaeng, Thung Yai West and Thung Yai East) were designated as the Thungyai-Huai Kha Khaeng Wildlife Sanctuaries World Heritage Site, Thailand’s first Natural World Heritage Site.
 
Mae Wong National Park (an important part of WEFCOM) was established in September 1987, as Thailand's 55th national park. Situated in the Thanon Thong Chai mountain range with peaks up to almost 2,000m above sea level and covered primarily by mixed deciduous and evergreen forest, it contains the source of the Mae Wong River, part of the Chao Phraya River's drainage basin.