03-08-2015

Estuary event details

Estuary	Barham River Estuary
Region	Corangamite CMA
Event type	Weather Event
Date and time	3 August 2015 13:50pm
Description	The Barham river estuary height was 0.71mAHD and steady on the 01/08/2015. There was 27mm of rain at Marengo in 24 hours and the estuary height was 0.98m at 07.50 on the 03/08/2015. The river mouth is open , the flow is out and the tide is low. At 13.50 there are 2m waves breaking at the river mouth. The river mouth is open but the flow is in and out with the swell. At 14.00 the still water height at the harbour is 1.06m AHD [2.03mCD] and there is a 15kt west wind. At the Paradise Barham river gauge at 14.14 the flow height is 0.534m. Sediment is medium. At 14.07 the estuary height is 1.38mAHD and at 14.30 it is !.40mAHD. The following day 04/08/2015 at 10.00 the estuary height is 0.91mAHD. My conclusion is that the high tide combined with the large swell backed up the river flow and elevated the estuary height from 0.98m to 1.40mAHD. On the 3rd of August much of the primary dune was eroded. The swell with high tide had easy access to the primary dune because the beach sand profile was already very low. A sand height monitoring pole [Pole 2] was located near the Heathfield estate beach carpark. Pole 2 on 05/04/2015 the beach sand was 2.68mAHD on the pole face and the sand was 3,27mAHD on the back of the pole. Pole 2 on 06/06/2015 the sand height was 2.15mAHD. Pole 2 on the 28/07/2015 the sand height was 1.67mAHD Pole 2 on the 03/08/2015 the pole had disappeared; washed away. The beach profile is extemely low and the primary dune that carries the GOR is vunerable to further storm erosion.