The temple is by the Chao Phraya river, which flows down to the capital, Bangkok, around 105 km (65 miles) to the south.
“The water level is now up to 1.5 meters and 150 soldiers are deployed in the area to fix the embankment,” said Wittaya Pewpong, governor of Ayutthaya province.
He said more than 200 of the 500 ancient temples in the province had been affected by floods.
Thailand has been hit by massive flooding caused by a tropical storm followed by seasonal monsoon rains, which usually fall from August to October.
Culture Minister Sukumol Kunplome put the damage to historical sites around the country at at least 100 million baht ($3.2 million).
Flooding has also affected Bangkok, which sits only two meters above sea level. The Chao Phraya river has overflowed into roads in some areas, although the authorities have reinforced its banks to prevent serious flooding.
Several trains to the north had been suspended because of the flooding, the Department of Disaster Prevention and Mitigation said.
Nearly 3 million acres (1.2 million hectares) of farmland was under water and the Meteorological Department has warned of more heavy rain in many parts of the country over the next few days.
The government has approved at least 8 billion baht ($256 million) in compensation for farmers and other people affected by floods.
In neighboring Cambodia, 164 people have died in floods since Aug. 13.
Keo Vy, deputy information director of the Cambodian National Disaster Management Committee, said more than 215,000 families had been displaced while roads, bridges and dikes had been destroyed.
“Affected people are facing the challenge of a lack of food,” he said.
More than 300,000 hectares (120,000 acres) of farmland was under water, he added.
