There are at least 3 spots here to jump from. One is about 40 feet, and the other 2 are about 60. Check the water first because it usually isnt too deep, around 10-15 feet.
From Waikiki: Take H1 west bound and get off at Pali exit. Go over the mountains. Turn right onto `Auloa Road after Kamehameha Hwy, at the fork stay to the left on Maunawili Road. Follow the signs to Maunawili Falls.