Main cause of flooding in Thailand is heave rain in monsoon season, overloaded capacity of dam, river. Geographical of Thailand, Northern Thailand is hill side, when there is heavy rain the water flow from northern river such as Ping, Wang, Yom, Nan to Chaopraya river, flood-plain area which is central area. When Kangsuaten dam and Naresuan dam are at full capacity, the water is released to central region to Pasakjolasit dam, if Pasakjolasit dam reach full capacity water will be released to lower region of Chaopraya river. Therefore flood happen.
Due to climate change, it become harder to predict the amount of water each year. There are about 6 main dams in central Thailand; only 3 of them were built to retain water. In 2010, first six month of the year Thailand face drought, so most of the dams retain water up to 90% capacity, when heavy rain occur dam capacity was full, flooding occur.