The cave-in, about two metres in length and about half a metre wide, is no more than 10 metres from the main pagoda, assistant abbot Phra Khru Arun Thammanuwat said, adding that the structure could collapse or start leaning if the damage increases.
He said the complex would be closely inspected to see if the foundation of the pagoda has sustained any damages. The monk said he personally felt that the damage would possibly expand and affect the entire wall.
“This is the first cave-in detected that is closest to the pagoda as far as I can tell,” he explained.
The monk said that the ancient technique used to build the pagoda, in which logs were used to create a basement that was then filled in by clay, would make the foundation weaker as clay soaks in water.
A three-metre barrier has been built around the Wat Arun compound to guard against the still-brimming Chao Phraya, though drainage is still underway. The cave-in was first detected two days ago and the Fine Arts Department has been notified of it.
Tharaphong Srisuchart, a senior official from the department, said the agency would soon launch a survey to see what can be done to prevent further damage and keep the pagoda’s foundation solid.
Wat Arun Rajwararam, originally known as Wat Chaeng, was part of the palace compound during the reign of King Rama 1. The temple was left abandoned for a long period until King Rama II restored it and extended the pagoda to cover 70 metres. The temple initially enshrined the emerald Buddha statue before it was transferred to the Emerald Buddha Temple in Bangkok in 1785.