Benalla flood claim rejected

Thursday 19 January, 2006

The CEO of the Goulburn Broken Catchment Management Authority, Bill O’Kane has rejected claims by the Member for Benalla that the decommissioning of Lake Mokoan will have a major impact on flooding in Benalla.

The current operational rules see the diversion of up to 2500 mgl a day from the Broken River and Holland Creek into Lake Mokoan. Mr O’Kane said the diversions do not materially affect flood heights in Benalla in a major flood. This was confirmed in the Benalla flood study conducted by Cardno Willing after the 1993 floods.

“The study concluded that even if the Lake Mokoan inlet channel was 1km wide it would only lower flood heights in Benalla in a major event by less than 5cm. This makes sense because the Broken River peaked in Benalla during the 1993 event at 112,000Ml/day and often the channel is not being operated during major floods.

Mr O’Kane did agree with Mr Sykes that the decommissioning of Lake Mokoan will have an impact on the frequency and height of minor floods.

“To be healthy, rivers must flood and to increase the height and frequency of minor floods without increasing the height and frequency of major floods gives us the best of both worlds.”

Mr O’Kane said the1963 Parliamentary Report into Lake Nillahcootie clearly states that its purpose was for water harvesting only.

“Cardno Willing looked into this issue too and concluded that even if Nillahcootie was empty at the beginning of a major flood event, it would have a negligible impact on flood heights in Benalla.

Release ends

For more information telephone Bill O’Kane (or his personal assistant Kathy Fuller) at the GBCMA on 58 201100.