Ichthys LNG project: Successful dredging campaign in Darwin Harbour, Northern Territory

INPEX Australia's 16 Mm3 dredging program for the Ichthys LNG Project in Darwin Harbour (executed between 2012 and 2014) is a leading ('Environomics') example of the careful harmonisation of protecting environmental and social values balanced against economic drivers such as schedule, cost and the importance of developing infrastructure for INPEX and the Northern Territory. Specific examples include the application of PIANC 100 to implement best (environmental) practice dredging methodologies; careful selection of a dredge footprint design and strong commitments to managing Aboriginal and non-Aboriginal heritage sites; transparent Regulatory processes involving an independent expert panel; interactive community engagement programs and an extensive nearshore environmental monitoring program. The selection of state of the art dredging equipment and methodology was achieved by INPEX through adopting best practice principles from international dredging guidelines (PIANC 100) in consultation with Dredging Contractor, plume modelling consultant, environmental monitoring specialist and a PIANC contributing author. The PIANC 100 process was fundamental in delivering a Project that eliminated the risk of drilling and blasting Walker Shoal; reduced shipping traffic to the spoil ground through the employment of jumbo trailing suction hopper dredgers (TSHDs) and minimised turbid plumes through significantly reduced TSHD overflow settings. The dredging footprint was carefully designed to ensure the protection of a series of Aboriginal sacred sites and WWII historical wrecks located in proximity. Cognisant of one of Australia's largest WWII battlefields (Darwin Harbour bombed 64 times), INPEX has undertaken an extensive (>120,000 man hours) identification, relocation and cataloguing program for 7000 artefacts unearthed in the East Arm of Darwin Harbour (over 280 ha), during a three year period. Chance finds procedures for potential heritage artefacts; routine monitoring of Catalina flying-boat wrecks and sophisticated early warning systems for navigating jumbo (> 200m) TSHDs in proximity to protected heritage sites are examples of the Company's strong commitment to heritage management. To address local government and community concerns related to the dredging program in Darwin Harbour, INPEX was required by Government to establish an independent dredge expert panel to act as an advisory committee to INPEX and the State and Commonwealth governments and embarked on an extensive community engagement and communications program. The program was successfully completed without any complaints or grievances received from the public.