The Department of National Parks, Wildlife and Plant Conservation (DNP) says it has no objection to allocating forest land on which to build new reservoirs if they are necessary, potentially including the Klong Wang Tanod project in Chanthaburi.
The reservoir project is opposed by conservationists, who fear it will destroy the habitat of big animals such as elephants, guars and banteng, because it is a significant low-lying forest ecosystem in the eastern region.
The forest zone also is a significant corridor linking two wildlife sanctuaries -- Khao Ang Rue Nai and Khao Soi Dao.
Ratchada Suriyakul na Ayutthaya, the department chief, said the DNP has not decided whether it will provide the forest land to serve the project, adding that further studies are required.
The issue has come under the spotlight following a report that Gen Prawit Wongsuwon, deputy prime minister in charge of water management, is expected to visit the area this month.
Gen Prawit said the government has made a concerted effort to find sufficient water resources to support the Eastern Economic Corridor (EEC) under its plan to promote and support foreign investment in future technology.
"Water security in the eastern region is a prime concern among investors, pushing the government's efforts to invest in water management projects to shore up their confidence," he said.
According to the Office of the National Water Resources, there are 17 projects aimed at adding a total of 406 million cubic metres of water to support both the farming and industrial sectors in 2023 and 2024, including the reservoir.
Panudech Kerdmali, secretary-general of the Seub Nakhasathien Foundation, said the Khlong Wang Tanod project sets a new precedent in unfair water-management practices as resources would be transferred from one river basin to the other.
The EEC should take responsibility for creating its own water security without relying too much on other sources, he added.
"We need the government to stop such acts that disturb forest land. They should protect such land inside the park that serves as natural habitats. We don't oppose the project, but we do need the dam storage to be scaled down to avoid infringing on forest zone use."
He said the Department of Royal Irrigation had previously agreed to reduce the size of the reservoir from 7,503 rai to 6,191 rai inside Khao Sib Ha Chan National Park and from 7,097 rai to 5,791 rai inside Khun Song preserved forest. However, he said this would be ineffectual.
Khlong Wang Tanod is one of four reservoirs along the Tanod basin that will store a total of 307.5 million cu/m of water to benefit 249,700 rai of farmland.
They will also support the EEC by diverting water to Prasae Dam in Rayong. Only one of the reservoirs has been fully built, with two more set for completion next year.
Meanwhile, the National Environment Board recently approved an environmental and health impact assessment (EHIA) for the Khlong Wang Tanod reservoir. It will have a capacity of 99.50 million cu/m and should be in place before the end of 2023.