Technical assessment of the Port of Brisbane offsite stormwater management pilot

The Port of Brisbane is situated at the mouth of the Brisbane River adjacent to the Moreton Bay Marine Park, an area of significant ecological value, which also supports important lifestyle, economic, fishing and tourism industries. Protection of water quality entering the Bay is a major focus for Port of Brisbane Pty Ltd (PBPL) particularly in regard to managing stormwater quality from its own lands. Working with a number of Government, not-for-profit and private stakeholders, PBPL is seeking to assess whether offsite stormwater investment in catchment restoration works, together with continuing stormwater management onsite, could efficiently improve water quality in the vicinity of the Port. As the majority of sediment and associated nutrient pollution in the Brisbane River and Moreton Bay results from channel (river, stream and gully) erosion in the Brisbane River catchment, the Pilot upstream catchment work targets restoration of degraded channels in Laidley Creek, one of South-east Queensland's regional sediment and nutrient pollution hotspots. The Pilot included three research projects aiming at assessing sediment erosion avoided by undertaking the works, quantifying the effects of reducing sediment erosion in the upper catchment on water quality at the Port and identifying the major sources of sediment pollution at the Port. The research findings demonstrated that a combination of onsite and offsite stormwater treatment provides the most efficient water quality outcomes. The effectiveness of the Pilot was tested by flooding in Laidley Creek caused by ex-tropical cyclone Debbie. Outstanding results are visibly evident in terms of reduced erosion when compared to adjacent areas.