160 likes | 777 Views
Agnes Water Desalination Project Preliminary Studies – Aquatic Ecology John Thorogood and Kylie McPherson. Adjacent to the existing water treatment plant Comprising: - A submerged offshore intake (600m off Chinamans Beach) - A submerged offshore brine
E N D
Agnes Water Desalination ProjectPreliminary Studies – Aquatic EcologyJohn Thorogood and Kylie McPherson
Adjacent to the existing water treatment plant Comprising: - A submerged offshore intake (600m off Chinamans Beach) - A submerged offshore brine outfall (800m off Chinamans Beach) Capacity – 2mL/day increasing to 12mL/day The Proposed Plant
Study Methodology • Review • Focused consultation • Field survey
The Existing Environment • ‘Oceanic’ water quality • Chinamans Beach characterised by surf, mobile sandy substrate, with rock out crops • Absence of tidal wetlands and subtidal seagrass • Significant reefs lie approx 60km offshore
Fisheries • Round Hill Creek is important for both recreational and commercial fisheries • Chinamans Beach supports recreational beach fishing • Trawlers (<6) operate offshore, targeting tiger prawns and saucer scallops
Conservation Significant Habitat • Tidal waters are part of the Great Barrier Reef Coast Marine Park. Adjacent to Chinamans Beach. Designated ‘General Use Zone’ • GUZ allows for ‘reasonable use, whilst still conserving these areas’ • Waters offshore of Chinamans Beach are designated GUZ of Great Barrier Reef Marine Park • Waters offshore also lie within the Great Barrier Reef World Heritage Area
Conservation Significance cont. • Along with entire GBR – listed as a Wetland of National Significance and World Heritage Area • No RAMSAR site • No wetlands of state or regional significance • No Fish Habitat Area • No Dugong Protection Area • No seagrass
State Coastal Management Plan • Agnes Waters lies within the Wide Bay Coast Coastal Management Region • Draft Regional Coastal Management Plan under preparation • Current issues include: loss of habitat, impacts of urban development on coastal landscapes and beach protection zones, beach erosion and impacts of marinas and dredging
Conservationally Significant Species • Chinamans Beach is nesting site for marine turtles (nesting, October-March; Hatching, December-May) • Offshore waters comprise humpback whale migration corridor
Permits • GBRMPA – GBRMP permit • Possible EPBC Act Referral • Marine Plants Permit - Unlikely
Potential Impacts • Construction Phase • Disturbance of nesting turtles • Disturbance of migrating whales (negligible impact) • Disturbance of fishers • Disturbance of beach and sea bed • Increased turbidity
Potential Impacts cont • Operation Phase - Intake of Fauna (turtle hatchling) (no impact on fisheries resources expected) - Discharge of Brine (elevated salinity) • Modeling predicts <0.6g/L increase at 100m • Mobile species (fish, prawns, etc) will avoid waters of elevated salinity • Some change in community structure of immobile benthic fauna likely to close proximity of diffuser
Mitigations • Construction Phase - Construct pipelines in the winter months to avoid turtle nesting; or avoid any night work • Operation Phase - Screened intake - Effective diffusion of brine effluent
Conclusions • Proposed site has low conservation significance with the notable exception of turtle nesting • Proposed site is physically robust • Predicted impacts considered reliable • Predicted impacts (after mitigation) are likely to be ecologically negligible and not significantly fisheries or conservation values