A pet dog swept away by a flash flood into a dam was rescued as a storm battered Thailand.

The Golden Retriever pooch named Phak Wan went missing during heavy rains until it was found stuck in Beung Na Kham dam in Uthai Thani province on August 25.

Footage shows the pooch struggling to stay afloat amid fast-flowing water.

Local authorities used a rope to tie around the pooch's body and pulled it onto the banks safely.

Phak Wan was taken to an animal clinic. The dog was uninjured but exhausted from being swept away in the water. The canine was reunited with its owners afterwards.

Floods caused by heavy rain have battered large regions of the north in recent days, with 22 people killed and up to 30,000 displaced , the Department of Disaster Prevention and Mitigation reported.

During a visit to the northern region of Nan over the weekend, acting prime minister Paetongtarn Shinawatra distributed food supplies to residents.

Thailand and neighbouring countries in Southeast Asia are at the start of their annual monsoon rainy season which sees soaring temperatures followed by powerful rain storms. The rudimentary infrastructure often struggles with the deluge, leading to widespread flash floods.