The Port Hedland Port Authority (PHPA) planned to dredge eight berths adjacent to the inner port area of Port Hedland within South West Creek. Due to the size and nature of the proposed works, environmental approvals were required under both Western Australian and Commonwealth environmental legislation.
The Situation
The Port Hedland Port Authority (PHPA) planned to dredge eight berths adjacent to the inner port area of Port Hedland within South West Creek. Due to the size and nature of the proposed works, environmental approvals were required under both Western Australian and Commonwealth environmental legislation.
PHPA was particularly concerned about any indirect impacts to the mangroves from sedimentation associated with the works. They were looking for an innovative way to measure these impacts in order to proactively manage them as they occurred.
Approach
Advisian were engaged by PHPA to undertake the Environmental Impact Assessment (EIA) and conformance monitoring, with the challenge of developing a method to measure sedimentation using acute and chronic stressors in real time.
PHPA adopted specialist sedimentation scanning technology; proprietary scientific equipment developed to understand sedimentation impacts in real time. The scanners can be set up either offshore (corals and seagrass) or onshore (mangroves), and are typically deployed half buried in the sediment.
Our consultants deployed the sedimentation scanners. Four times a day the scanners would scan the surrounding sediment levels, regardless of tidal height or metocean conditions, and send this data to the our monitoring office. The data was then monitored and analysed by our mangrove physiologists against trigger values developed as part of the EIA, and reported as part of the management framework.
Results
The successful application of this technology has set a new benchmark for mangrove impact assessment monitoring. This approach represented an ideal program for both the PHPA and Advisian, who were able to monitor all aspects of the project in real time, whilst proactively managing the mangrove impact and reducing HSE risk by limiting field exposure for personnel and the associated environmental disruption.
