Water flows 16.6 km from Tantangara Reservoir to Lake Eucumbene via the 3.1 to 3.35m diameter Murrumbidgee-Eucumbene tunnel falling 40 m in the process. Flow is controlled by a 1.83 x 2.13 m regulating gate such that a maximum of 20 cumecs is allowed. Flow downstream into the Murrumbidgee River is controlled at the dam and comprises two by high shafts, from the outlet works tower and tapering to diameter before passing through a diameter nozzle to river diversion tunnel, with a capacity of