This waterfall is downstream from the Upper Kothmale dam. Water is released from the sluice gates of the dam on and off, to keep the waterfall going.
Video at present:-
http://www.youtube.com/watch?v=g1Ztnka9PFU
Video of the waterfall before completion of the dam:-
http://www.youtube.com/watch?v=5b9srzpodlM
See an earlier picture taken before the completion of the Kothmale Dam:-
http://philipveerasingam.blogspot.com/2011/12/stclairs-waterfalls-pathana-hatton-sri.html
Video at present:-
http://www.youtube.com/watch?v=g1Ztnka9PFU
Video of the waterfall before completion of the dam:-
http://www.youtube.com/watch?v=5b9srzpodlM
See an earlier picture taken before the completion of the Kothmale Dam:-
http://philipveerasingam.blogspot.com/2011/12/stclairs-waterfalls-pathana-hatton-sri.html