The Gosthani rises in the Ananthagiri Hills of the Eastern Ghats and flows through the Borra Caves which lie near its source. It is the largest river flowing through Visakhapatnam city. It flows for 120 km before joining the Bay of Bengal through an estuary near Bheemunipatnam. The river basin drains the two coastal districts of Vizianagaram and Visakhapatnam. The basin exhibits a subdendritic and dendritic pattern of drainage. The Gosthani's is a minor river basin with a total drainage area of less than 2000 km2. Much of the basin is covered by khondalite group of gneissic rocks. About 3% of the total area of the Visakhapatnam district is under the Gosthani basin. The river is rainfed, receiving an average rainfall of 110 cm most of which comes from the south-west monsoon. There are sever