There was a thread on UM less than a year ago which included some info on the major flood in Udon in July 2000.
Thai Airways had to cancel flights to Udon because the runway and taxiway were submerged under some 30cm (a foot) of water:
And still existing in cyberspace from a local website before the days of UM:
Udon Thani Recovers from Flood.
People and business sectors start repairing their houses and properties. This water flooded into the town, causing the worst deluge in 100 years. Some lower areas still under water level and still need help from outside. Wave from big trucks damaged most of house doors.
Many people are suffering from water diseases. Central hospital and some private hospitals anounced free treatment to people who were infected by the water diseases.
The big flooding was caused by 274 mm of rain in one day. Governor Kiatipan Noymanee ordered to dig a channel across a highway and another at the base of railway track to drain water from Udon Thani. A steel structure from Bangkok was used to reinforce the railway track to let water run through and now train from Nong Khai can go through to Bangkok. A temporary bridge was also installed over a channel dug across the Udon Thani-Sakon Nakhon highway.
Bangkok Post report that out of the 47 square - kilometre municipality, about 45 square kilometres were flooded. Damage to to public utilities was estimated at 213 million baht, the governor said. Eleven villages in Tambon Samphrao and many farms were also flooded when water was drained out of the town.
Udon Thani Flood 2000
No one prepared for this disaster even the governor of Udon Thani. Lack of food spead around the city in all subroads. Some of 1 floor houses are completely underwater. Many people use roads in the higher area for their temporary home. People have to help themself while waiting for help from government section.
On 14th July, Ban Jun dam had some crack due to water overload. All force from government section and from public had to go to deal with the crack and finally they designed to dig at the back of the dam to release 2 million square meters water from the dam. This made water level in Udon Thai rose up. And to help release water from city area, the government had to dig the railway that connect Udon Thai to Khon Khan. People from Nong Khai above Udon Thani who want to travel to Bangkok have to go off the train at Udon Thani, use bus to transit to the next train station. Flight from Bangkok to Udon and in reverse must stop for 3 days dues to the water flood the runway. And just start flying on 15 July in the afternoon.
Fortunately, there is no heavy water during this few day after the heavy rain. The water level are going down today and some higher area have no flood. But there is still a bad news for the next 4 days.Meteorological Department predicted that there will be another storm on 19 and 20 July and all people in Udon Thani must be prepare to cope with the flooding situation again.
Reporter of Siang Issan News said that there are 4 people died in this flood. 2 were death by electric shock and 2 were drowned when they were trying to fishing in a flooding canal.
Link to original site: http://udon.loxinfo.co.th/~unthanin/news.html