Swethganga is a spring located at Bamhini, about 10 km west of Mahasamund
, in Mahasamund District
. This spring is close to an old temple dedicated to Lord Shiva
. There is a constant flow of water from the flagstone pit (Khund) to the river.
The festival is celebrated on Mahashivratri and on the full moon of Maghi month. There is a custom in which group of devotees (Bolbum Kawariya) come here during Sravan month. After taking bath in this spring, they take 2 pots of water and tie each on the end of a stick, known as kawar. The people carry this water on their shoulder and walk to Sirpur, situated about 50 km away, uttering the word 'Bolbum'. The water is then showered on the shivling at the Gandhesheshwara Temple.