Bhagavatapurana 10.16.5

5. Touched by the breeze that bore the spray from its poisonous waves, creatures, mobile or immobile, living on its banks met death.

6. Seeing how virulent the poison of the serpent was and how the river was spoiled by him, Sri Krishna who had appeared on earth for the very purpose of putting down the wicked, climbed up a very lofty Kadamba tree, tightened his girdle, stroked his arms and (from a great height) jumped down into the deep pool of poisonous water.