Wivenhoe dam Type of dam Earth and rockfill Storage Catchment area 7020km2 Average annual rainfall (Upper Brisbane river) 880mm Full supply level (FSL) EL 67 Storage capacity at FSL 1.15M megalitres Inundated area at FSL 10,820ha Temporary flood storage available 1.4M megalitres Embankment Crest level EL 79 Total crest length 2.3km Height 59m Total volume of embankment fill 4x106m3 Spillway Type Gated concrete spillway Five radial spillway gates 12m wide x 16.6m high Design flood max water level EL 77 Design flood max outflow 11,700m3/sec