The Munroe Isle of Kollam district was formed as a result of the sediment depositional process by river Kallada and Ashtamudi Lake; hence it is laccustrine in origin. There are 8 smaller islands that make up the archipelago. In the recent times, the island has been experiencing the threat of increased water level. Flooding and consequent sinking (3 to 4 meters ) is the major issue faced by the inhabitants of this island. Due to a shortage of shelter and daily revenue, almost 400 families have departed the island. The current study identified many reasons behind the sinking of Munroe island such as sea level rise, climate change, faulty agricultural practices etc. The inputs received from various scientific studies, dailies, Panchayath documents and the information and support got from the inhabitants served to this study. A direct field visit and questionnaire survey in a random sampling method and provided it to a 100 households were conducted to understand the major reasons behind the sinking of this island from the residents of Munroe island who are the direct victims of this phenomenon. Geographic Information System (GIS) tools(QGIS, Google Earth) were used to find out the sunken areas of Munroe Thuruth.