Abstract
Proposed outlet works for the Ash Pond Dam of the Wangi power Station comprise two six foot diameter pipes discharging inton a concrete energy dissipator and thence into an open channel with unlined bed and rip rap banks. Model tests of the original outlet design for the maximum design flow of 600 cusecs indicated the likelihood of unsatisfactory asymmetrical flow in the discharge channel, with scouring of the bed and undercutting of the left bank near the outlet. Design modifications tested in the model included the addition of sills, an increase in the height of the wing walls of the energy dissipator, and a change in the rip rap banks.