Coasts & Estuaries - City of Port Adelaide Enfield - SA.Gov.au

Coast & Estuariesentering the river, and review the practices of shipyards and marinas to reduce pollution from theseindustries. Road runoff was also identified as an area requiring further investigation of strategies tostop pollutants such as lead and zinc from entering the river via stormwater discharge.Thermal DischargeSeveral facilities in and around the Port Adelaide River release hot water as a result of industrialprocesses, including the Pelican Point, Torrens Island and Osborne power stations. Due to the largevolume of water present the impact of thermal discharges may be localised as overall backgroundtemperatures are not significantly altered by thermal discharge.However further investigation into the impacts on fauna and flora in the area is required. One studyconducted near the Torrens Island thermal outfall indicated that near the point of discharge somespecies of intertidal animals had reduced in population or had been eliminated, while other previouslyrare or absent species had become more common (Thomas et. al., 1986). A more recent studysuggested that thermal discharge, in combination with elevated nutrient levels and increased algalgrowth, had contributed to reduced biomass and diversity of intertidal fauna in parts of the estuaryand altered the fish species composition (Jones et. al., 1996).Development of Barker Inlet and Port Adelaide RiverIncreasing development adjacent to and in marine water bodies and coastline, including housing,marinas and boat ramps, places significant pressure on delicate coastal and marine environments.If sited incorrectly marinas and boat ramps can disrupt sand movement, degrade habitat and waterquality, and disrupt the natural flows of coastal creeks and streams (Department of Environment andHeritage, 2006).The new Port Waterfront residential development is a significant new coastal development within theCity of Port Adelaide Enfield. Approximately 2000 new residential dwellings will be built along the PortAdelaide River, including direct water frontage dwellings. Increased stormwater discharges directlyinto the Port Adelaide River is a potential pressure, some of this impact will be mitigated though urbanstormwater planning, installation of rain water tanks and gross pollutant traps.The approved construction and operation of approximately 550 marina berths within the Inner Harborat Port Adelaide, has the potential to place significant pressure on the Port Adelaide River andassociated ecologies. The Coast Protection Board has raised several of these issues including, theincreased potential for Caulerpa taxifolia and Caulerpa racemosa to be dispersed through the marineenvironment via boats, the long-term cumulative effects of large boating facilities including ballastdischarges, accidental discharges, changes to flow regimes, and litter, and the impacts on dolphinsincluding habitat, water quality and direct harm. Pollutants of potential concern include petrol, sewage,household garbage and boat wash-down effluent.The EPA is providing advice to the development in regard to these issues.Dredging of the Port Adelaide RiverWork has been completed on deepening the channel at Outer Harbor from 12.2 metres to 14.2metres to accommodate large Panamax ships as part of the Flinders Ports development. Severalother one-off or regular maintenance dredging occurs at various sites along the river. Dredging haspotential significant environmental consequences on benthic (living on or in sediments of the seafloor) flora and fauna and the re-distribution of exotic marine species.The long term effect of dredging activities is not well documented. Further research is required toinvestigate the impacts of dredging and recovery rates in specific locations and in various conditions.150