The draining of the water from the national park is part of ongoing efforts to rescue 12 young footballers and their coach who have been trapped in Tham Luang cave since June 23.

Mr Grisada said according to a report from the governor of Chiang Rai, the water drained from the national park has inundated about 1,600 rai of rice fields in three tambons of Mae Sai district, or about 8% of the entire area for rice farming.

He said the affected area may be larger, pending a further examination, as more water will be drained out in a large quantity.

Affected farmers will get a compensation of 1,100 baht per rai. The province can use its own budget of 50 million baht to pay the compensation as soon as possible without having to seek approval from the cabinet, Mr Grisada said.

However, the matter must go to a provincial level committee for consideration. In a show of spirit of volunteerism, several of the farmers have offered to have water drained out from the cave inundate or pass through their paddy fields.

Mr Grisada said new rice seeds have been prepared to be distributed to the affected farmers.

At the same time, the Royal Irrigation Department director-general has been assigned to examine routes to divert water from the flooded farmland into waterways such as Kham and Mae Sai rivers, he added.