Severe flooding, which is associated with numerous outbreaks of a wide range of infectious diseases, particularly those caused by enteric viruses, occurred in all areas of Thailand in 2011. To determine the prevalence of five human enteric viruses, namely enterovirus, rotavirus (RV), norovirus (NV), hepatitis A virus (HAV), and hepatitis E virus, in the flood water, 100 water samples were collected from flood-damaged areas in central Thailand. Viral RNA was extracted from concentrated samples and analyzed by RT-PCR and sequencing. NV was the most commonly detected pathogen in the tested samples (14%). RV and HAV were detected in 9% and 7% of samples, respectively. This study is the first to detect enteric viral genes in flood water in Thailand. Furthermore, it is the first to detect an NV gene in any type of environmental water in Thailand. These results provide useful information for estimating the risk of flood waterborne viral infection.