
Karnataka Tourism puts the fullest flow at July-December, especially just after the monsoon; it weakens later in the dry season. Go on a weekday morning to beat the queue at the viewing bridge. Bathing and swimming are not allowed, and the path runs through a private coffee estate, so stay on it. In heavy rain, access has been restricted, so check before you drive out.
The falls sit inside a coffee and spice estate about 8-9 km from Madikeri and were once called Jessy Falls, after the daughter of an English chaplain. Wikipedia credits Neravanda B. Nanaiah with buying the land and turning it into a plantation, which still surrounds the falls today.