32331
After the Mekong 's waters crest - when its downstream channels can handle the volume of water - the flow reverses , and water flows out of the engorged lake .
 location: Mekong
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: location, person, organization 
Text: {0} 
 Entities: Mekong 
Answer:
 location: Mekong