The Nerbudda river, one of the most important sacred rivers, originating from Amarkantak is believed to have descended from the sky by the order of Lord Shiva. The personified river is variously represented as being daughter of a Rishi named Mekala (from whom she is called Mekala and Mekala-kanya), as a daughter of the moon, as a 'mind-born daughter' of the Somapas, and as sister of the Nagas. It was she who brought Purukutsa to the aid of the Nagas against the Gandharvas, and the grateful snake-gods made her name a charm against the venom of snakes.
Example via www.ramdass.org: If I’m Alive, I’ll Talk to You