- Ganga is the longest river in India. The Ganga originates as the Bhagirathi from the Gangotri glacier.
- Before it reaches Devprayag in the Garhwal Division, the Mandakini, Pindar, the Dhauliganga and the Bishenganga rivers merge into the Alaknanda and the Bheling drain into the Bhagirathi.
- The Pindar River rises from East Trishul and Nanda Devi unite with the Alaknanda at Karan Prayag.
- The Mandakini meets at Rudraprayag.
- The water from both Bhagirathi and the Alaknanda flows in the name of the Ganga at Devprayag.