The Purna River originates in the Ajanta Range of hills at an altitude of 838 m. It flows in a south-easterly direction for a distance of 373 km before joining the Godavari at an elevation of about 351 m. The Dudna is its longest tributary. The catchment area of the Purna River, including its tributaries is 15,579 km2 which lies in a low rainfall zone which gets 711 mm to 889 mm of rain in the year.