Flying Fish Point Rock Revetment Upgrade: The Application of ‘Green Engineering', Fish Friendly Features and Other Innovative Measures

Abstract

Situated in Tropical North Queensland and on the doorstep of the Great Barrier Reef Marine Park, Cassowary Coast Regional Council has over 3.5 kilometres of coastal shoreline structures that provide protection to its community and their assets. Flying Fish Point is located immediately north of the Johnstone River mouth and has a history of shoreline erosion. In response and over time, Council has undertaken a variety of mitigation measures, including the construction of rock revetments. Early 2017, Council resolved to remediate the existing rock revetments between William to Ruby Street along Flying Fish Point. Our proposed paper will focus on the already constructed remediated revetment (known as Stage 1) between William and Edward Street. While the design and construction of rock revetments is a relatively proven science, Council set the following terms of reference; 1. Provide a robust and resilient coastal protection asset that provides enhanced environmental benefits and scientific research potential through design innovation, whilst still achieving favourable whole of life costs. 2. Increase community and environmental values by incorporating innovative ‘green engineering’ design through the application of fish friendly features and other innovative measures. 3. Increase the level of coastal protection immunity and structural performance by remediating the existing rock revetment to the relevant prescribed tidal works requirements. 4. Undertake peer review of the design process, representing Council due diligence and ensuring Council objectives are met. In response, Council collaborated with James Cook University’s TROPWater division, supporting the revetment design process with the view to increasing marine habitat and improve aesthetic and environmental values for the community. Council’s designers, SMEC, faced a number of challenges throughout the design and to ensure that enhanced environmental outcomes did not compromise structure function, performance and tidal works requirements. The incorporation of ‘green engineering’ within a rock revetment, is the first of its kind along the Great Barrier Reef coastline. It is expected that the remediated rock revetment between William and Edward Street will provide important data and knowledge for other coastal Council’s to use in achieving multiple benefits from similar coastal erosion protection engineering projects. Other innovative measures undertaken during the design process included; • The use of unmanned aerial survey (UAV) for initial survey and for ongoing monitoring of the wall. • Reuse of existing insitu rock and leveraging Horton Coastal Engineering for design assurance through the peer review process. The project has been developed in line with the International Year of the Reef 2018 and the implementation of the GBRMPA Reef Blueprint for reef resilience and testing of the GBRMPA Intervention guidelines (draft). In particular, this project is relevant to the GBRMPA Reef Blueprint Active Localised Restoration priority activity areas: 1. Testing, improving and scaling up local-scale reef restoration methods – based on the best available science – for potential application across the resilience network. 2. Facilitating opportunities for community and industry participation in local scale restoration and research though partnering with Reef Guardian Schools and engagement with Local Marine Advisory Committee.