Gold coast seaway smartrelease decision support system: optimising recycled water release in a sub tropical estuarine environment

摘要

Gold Coast Water is responsible for the management of the water, recycled water andnwastewater assets of the City of the Gold Coast on Australia’s east coast. Excess treatednrecycled water is released at the Gold Coast Seaway, a man-made channel connecting thenBroadwater Estuary with the Pacific Ocean, on an outgoing tide in order for the recycled waternto be dispersed before the tide changes and re-enters the Broadwater estuary. Rapid populationngrowth has placed increasing demands on the city’s recycled water release system and anninvestigation of the capacity of the Broadwater to assimilate a greater volume of recycled waternover a longer release period was undertaken in 2007. As an outcome, Gold Coast Water wasngranted an extension of the existing release licence from 10.5 hours per day to 13.3 hours pernday from the Coombabah wastewater treatment plant (WWTP). The Seaway Smart Release Projectnhas been designed to optimise the release of the recycled water from the Coombabah WWTPnin order to minimise the impact to the receiving estuarine water quality and maximise the costnefficiency of pumping. In order achieve this; an optimisation study that involves intensivenhydrodynamic and water quality monitoring, numerical modelling and a web-based decisionnsupport system is underway. An intensive monitoring campaign provided information on waternlevels, currents, winds, waves, nutrients and bacterial levels within the Broadwater. This datanwas then used to calibrate and verify numerical models using the MIKE by DHI suite of software.nThe Decision Support System will then collect continually measured data such as water levels,ninteract with the WWTP SCADA system, run the numerical models and provide the optimal timenwindow to release the required amount of recycled water from the WWTP within the licencenspecifications.