Swamps are wetlands where water oozes out from surface also known as 'Oogals'. In past time, low lying area of Doon Valley were having an interconnected chain of swamps. But excessive human interference resulted in destruction of majority of Doon Valley swamps. Swamps are ecotones exhibiting high biodiversity of palatable species making them susceptible to overexploitation. The present study is conducted in Mothronwala fresh water swamp of Doon Valley which is under anthropogenic threat. A total of 62 species are recorded from vegetation mosaics. The diversity in vegetation mosaics of Mothronwala swamp is represented by 26 families, 51 genera and 62 species. Poaceae is the most dominant family of vegetation mosaics. The most dominant life form of vegetation mosaic are herbs followed by shrubs and grasses. The nearby population is dependent on swamp forest for fodder, food, fuel wood and medicinal plants leading to loss in floristic diversity. A proper conservation strategy is needed for maintaining biodiversity of freshwater swamp.