The 123-year-old Buddhist stupa known as Phra Tat Non Tan collapsed on Sunday.
The Fine Arts Department said on Monday it would cost at least 20 million baht to reconstruct, or build a new one, in the same likeness. The structure itself was beyond repair.
The stupa is at Ban That in tambon Non Tan of Tha Uthen district. It was built in traditional brick-and-mortar style and believed to date back to 1902, according to the department.
Phra Tat Non Tan is considered a significant historical landmark, tied to the migration and settlement of the Tai Yor ethnic group in the district. It had been restored in 1993 and was registered as a historical site in 2017.
Cracks had been detected in the stupa since 2019 and a budget of 2.6 million baht previously approved for repairs. It collapsed on Sunday before the work could be completed. (continues below)
On Monday, a team led by Tha Uthen chief Chinawat Thongpricha inspected the site. They said waterlogged soil and a weakened foundation caused the collapse, which also damaged the adjacent, old ordination hall.
Officials said Fine Arts Office Region 9 was drafting plans for a new stupa that will replicate the original design. The reconstruction budget would top 20 million baht.
Among the artifacts rcoveredfrom the rubble were a five-tiered brass finial from the top of the spire measuring two metres in length, two gold necklaces weighing a total of three baht believed to have been donated during the 1993 restoration, and three antique bronze Buddha images in the Chiang Rung style.