Was lucky to get an opportunity to visit the Surathalee Ella in Belihuloya during a quick official visit I had to make. Indeed was gorgeous and a rare sight. This Sri Lankan Waterfall is quite narrow at the top and spreads after it reaches it's second layer. The walk from Main road is a mere 50 meters through lush forest cover which is gorgeous.
Hence, recommend you hoping off the vehicle (after say 10 km after passing Belihuloya rest house - 3 km from Uni of Sabaragamuwa Junc) and have a look - This was during the dry season, so guess there will be more volume of water during rainy season.