High spring tides over the Christmas period caused Gladstone Ports Corporation (GPC) to implement its Turbidity Management Plan for the Western Basin Dredging and Disposal Project.
“The Turbidity Management plan (TMP) was implemented over the Christmas Boxing Day period to minimize the impact of dredging on the high spring tides,” Mr Zussino said.
“We anticipated the four metre high spring tides over this period would impact on turbidity in the harbour, so we implemented the TMP before we hit the 99th percentile.
“In fact we implemented the TMP after turbidity readings at one site (ST1), adjacent to the bund wall reclamation area at Fisherman’s Landing, hit the 95th percentile after 24 hours.
“No other monitoring stations recorded any exceedances.
“What this means is that we stopped the cutter suction dredge operations just after the peak of the high tide for three hours on the outgoing tide.
“This allowed us to gauge whether the operations of the dredge were impacting on the high tidal outflows.”
Mr Zussino added the TMP was kept in place over the Christmas Boxing Day holiday period to minimise the impacts of dredging on turbidity levels in the harbour.
“DERM received daily water quality reports over the Christmas New Year period and were aware we had implemented the TMP,” Mr Zussino said.
“We are committed to ensuring the protection of our harbour and the local environment, and the Western Basin Dredging and Disposal Project is being managed under world’s best practice for dredging, informed by the Dredging Technical Reference Panel.”
The Turbidity Management Plan has been approved by DERM.
Dredging Today Staff, January 5, 2012; Image: westernbasinportdevelopment