Dam land has been used to grow rice since 1979.
About 180 farming families have filed a complaint with authorities in Battambang province asking that they be given land in compensation for a plan to rehabilitate a Khmer Rouge-era dam.
The farmers said they had used the vast collapsed Chork dam as rice fields for decades and said the proposed US$2 million plan to rebuild the dam would rob them of their livelihoods.
Long Phal Khun, an official at the provincial Department of Water Resources and Meteorology, said the rebuilding project is being funded by the Asian Development Bank (ADB). He said the project would begin in November and would irrigate 8,000 hectares of land.
Rath Mom, a representative for the farmers, said the Khmer Rouge had built the dam and that families had farmed the 500-hectare site since the regime was driven out in 1979.
"We are asking the authorities to provide us with new land on which to farm," Rath Mom said.
"We need to be compensated for land. We don't need money. We are farmers, so we need land to grow rice."
The dam lies between Chork Touch and Chork Thom villages, which are in Kor Koh commune, Moung Russey district.
District Governor Lom Som told the Post that the affected area is state land and does not belong to the farmers. He said the farmers had been told in the 1980s that they could use the land but would not be allowed to own it.
Lom Som said the refurbished dam would provide essential irrigation to thousands of farmers in the area and would allow them to harvest two crops annually.
"The rice fields belong to the state, so there is no need to compensate them," he said. "I told them earlier this year they could still plant rice in the dry season when the water levels drop. Some [other] people have instigated this complaint."
An ADB spokesperson confirmed that the bank is funding three dam reconstruction projects - Daun Av, Canal Number One, and Chork - in the province as part of its $20 million Northwest Irrigation Project.
When asked about compensation, the ADB spokesperson said: "For any projects funded by the ADB, which have a social or economic impact, the ADB will ensure that the bank's resettlement policy is adequately applied before the start of the project."
Uo Vorn, a member of Kor Koh's commune council, said the collapse of the dam wall had meant the water level was now no more than 1 or 2 metres deep. Officials from the provincial ministry had surveyed the land to assess its potential.
"After it has been repaired, it will help the farmers in times of drought and will allow them to harvest rice twice a year," Uo Vorn said.
The farmers have also filed a complaint with human rights groups AdhocC and Licadho. Heng Say Hong, an investigator with Licadho in the province, confirmed that his office had received the complaint. He said they would ask the local authority to try to deal with the issue.
"They should resolve this problem with the people," Heng Say Hong said.
"They should look to provide them with paddy fields in other areas or to provide compensation because these families have been on the land since 1979, and they have no other way to feed their families."