This is a statement from Panudet Kerdmali, Chair of the Seub Nakhasathien Foundation, reflecting the issue of data discrepancies between the Department of Irrigation’s EHIA report and the natural resource research data from the Department of National Parks, Wildlife and Plant Conservation concerning the structure of the‘Khlong Wang Tonod Reservoir.’Located in Chanthaburi Province, with a catchment and reservoir area totaling 11,982 rai, including 5,791 rai within the Khun Song National Reserved Forest and 6,191 rai inside Khao Sip Ha Chan National Park.
Currently, Environmental Impact Assessment (EIA) and Environmental and Health Impact Assessment (EHIA) reports serve as primary mechanisms to protect and reduce impacts on natural resources, the environment, and public quality of life from development projects such as dams, power plants, mines, or industrial estates, by establishing preventive and remedial measures before construction begins.
However, in reality, these tools have been questioned for their academic reliability and factual accuracy, leading to a fundamental question: is the EHIA merely becoming a rubber stamp to legitimize government projects?
Structural flaws repeatedly appear in EHIA reports of various projects, including large dam constructions in protected forest areas such as the‘Khlong Wang Tonod Reservoir project.’This project is proceeding despite ongoing public criticism regarding the project's cost-effectiveness and the accuracy of its EHIA.
Comparing the approved EHIA report with survey results from the Department of National Parks, Wildlife and Plant Conservation, along with perspectives from academics and environmentalists, Thairath Plus has compiled eight observations concerning inconsistencies in the EHIA report for the Khlong Wang Tonod Reservoir project in Chanthaburi Province.
The Department of Irrigation’s EHIA report states approximately 21,982 large trees; however, a field survey by the Department of National Parks (conducted from 2–16 September 2023 using 80 survey plots) found that in the dry evergreen forest area affected, approximately 4,370.93 rai, there are 346,081 large trees with a diameter at breast height (DBH) of 10 centimeters or more.
Additionally, about 2,614,415 young trees and saplings, plus over 19,195,268 seedlings, were found—totaling tens of millions of plant resources omitted from the EHIA’s true impact assessment.
The EHIA report classifies the forest as only‘mixed deciduous and forest regeneration areas,’which conflicts with the Department of National Parks’ survey identifying it as‘lowland dry evergreen forest.’This is a large, highly productive forest with evidence of wildlife use and natural salt licks—key mineral sources for wildlife—distributed throughout the area.
Within Khao Sip Ha Chan National Park, there is also‘one of Thailand’s largest Kapho plant communities.’Building the Khlong Wang Tonod reservoir would result in loss of natural forest habitat and biodiversity.
Dr. Nonn Panitvong, a freshwater ecosystem specialist, revealed that the EHIA report used obsolete scientific names for fish species and failed to accurately survey or assess populations of rare and endemic fish that are now very scarce in aquatic ecosystems.
Errors were also found in recording flora and fauna data; for example, the EHIA reported the presence of white-handed gibbons, but in reality, these were not observed—instead, crowned gibbons were found.
The EHIA significantly underestimates wildlife area use, conflicting with field survey data and photos from the Department of National Parks, which identified 49 individual wild elephants and a herd of about 60–80 elephants, with recent data indicating over 70 wild elephants continuously using this area as a migration corridor. Furthermore, this area serves as habitat for large mammals such as gaur, clouded leopards, deer, muntjac, wild boar, and Asiatic black bears.
The EHIA report assesses that affected wildlife‘will be able to naturally relocate or migrate to adjacent remaining forest areas to escape flooding.’The Seub Nakhasathien Foundation and experts explain that this lowland forest area is crucial for connecting to the Khao Ang Rue Nai Wildlife Sanctuary.
Flooding over 7,000 rai of lowland forest in Khao Sip Ha Chan National Park would adversely affect tens of thousands of surrounding rai because large mammals and elephants cannot forage in flooded lowlands, immediately reducing their feeding areas and ultimately restricting their territories and habitats.
Although the EHIA acknowledges that the reservoir will flood wildlife habitats and natural corridors, especially for elephants, it lacks behavioral models and realistic impact assessments.
When the lowland forest—primary sources of water and food—is submerged, elephants and other wildlife are forced to forage outside the protected forest into surrounding agricultural lands, exacerbating human-elephant conflicts in the eastern region and causing severe damage. In 2025, there were over 610 reported incidents of wild elephants leaving the protected area.
Dr. Nonn further noted that according to the Department of National Parks’ regulations, projects impacting the environment must reforest twice the affected area (about 24,000 rai). However, the subcommittee clearly stated that the project area lacks sufficient suitable land for reforestation, making the EHIA’s cost-benefit analysis inaccurate, as it includes the value of non-existent new forest plantations as project benefits.
Public consultation during the EHIA phase often focuses only on water allocation for agriculture, while the main goal of the reservoir is to ensure water security and diversion for large industrial sectors in the Eastern Economic Corridor (EEC). This may lead to incomplete public consent due to lack of accurate scientific information.
Meanwhile, the EHIA offers no alternative water management options with lower impacts, such as proposals from the Seub Nakhasathien Foundation and the Department of National Parks to reduce the reservoir size to about 657 rai to conserve natural resources and still provide agricultural water.
Or enhancing the efficiency of three existing reservoirs nearby—Khlong Prakaet, Khlong Pawah Yai, and Khlong Hang Maew—which can supply water to alleviate drought without destroying additional protected forest and wildlife habitats.
Amid debates about the Khlong Wang Tonod reservoir project, the greatest concern may not be whether the project is cost-effective or how significant its environmental impacts are.
Rather, the bigger and more important issue is that the EHIA report, which serves as the primary data source and starting point for project approval decisions, is filled with flaws, discrepancies, and information contradictory to on-site realities.
Ultimately, if this academically flawed EHIA report can be approved, endorsed, and used asa ‘rubber stamp,’to legitimize advancing dam construction in protected forests, it raises the question: no matter how distorted the environmental impact assessment is from reality, will state projects still proceed anyway?