Pattern of closures
Mallacoota Inlet closes infrequently but, when closed it can remain so for a considerable period of time. Closures can last anywhere between 9 months and 3 years with a relatively static water level until high inflows cause flooding of the foreshore.
Sand transport from the east during either storms or persistent currents is the most likely closure mechanism.
There have been two recorded closures in the past 8 years (October 2004 and February 2010).
Location of flooding
When closed, the water level remains around 0.8m for a prolonged period. Water levels can be determined by viewing the gauge mounted on the jetty at the boat ramp.
Flooding can occur over wharves, camping areas, car parks, boat ramps and moorings.
Level required for a successful opening
It is unlikely that a successful opening can be achieved when the water level is below 1.5m. If an opening is to be attempted in a westerly location, water levels need to be higher (>1.7m) as the sand build up inside the estuary will prevent a rapid connection to a deep channel.
In the past, there has been a long period of closure and the water level has remained relatively static. The opening is then likely to be required at very short notice with a forecast of heavy rainfall. The hydrological response time of the catchment will give, at best, a couple of days’ notice before floodwaters rise rapidly requiring an opening to be initiated.
Responsibility for an opening
Parks Victoria coordinates the works component of the opening which is approved by East Gippsland CMA.
Location of gauge
A gauge has been mounted on the public jetty near the boat ramp.
Printed information about estuary entrance management at Mallacoota Inlet can be obtained here (PDF, 320KB).