The Coastal Floodplain Prioritisation Study is a product of the NSW Marine Estate Management Strategy (MEMS) developed by the University of NSW Water Research Laboratory (WRL). The separate catchment reports and data packages cover the floodplains of seven NSW estuaries - the Tweed, Richmond, Clarence, Hastings, Macleay, Manning and Shoalhaven River estuaries. The report and geodata package is a centralised information source for managing water quality from diffuse agricultural sources from coastal floodplains now and into the future.

The prioritisation of the floodplain subcatchments and associated management options presented in these reports are an application of the methods outlined in the Coastal Floodplain Prioritisation Study – Background and Methodology (Rayner et al., 2023) (i.e. the ‘Methods report’). The Methods report outlines the theoretical processes behind the applied prioritisation approach and provides comprehensive detail and justification on the study approach and methods used.

The seven catchment reports provide an overview of floodplain processes, collate relevant datasets and maps, and describe and use the evidence-based multi-criteria analysis to identify and prioritise acid sulfate soil and blackwater (de-oxygenated water) production risk from sub-catchments. Estuary specific tidal hydrodynamic models were used to determine current and future floodgate infrastructure functionality and floodplain drainage vulnerability risk considering sea level rise. Information is detailed by sub-catchment and potential staged management responses to address sources of poor water quality are described.

The geodata package includes information on floodplain drainage infrastructure (floodgates and drainage networks, including photos), soil acidity, acid depth and hydraulic conductivity, floodgate condition and floodplain sea level rise vulnerability and drain cross sections. Collated catchment specific data relevant to the implementation of management options and maps of the acid and blackwater risk prioritisation for each of the seven floodplains are also provided.

The Coastal Floodplain Prioritisation Study datasets for the following regions can be accessed in the Related Datasets section below:

• Tweed River
• Richmond River
• Clarence River
• Hastings River
• Macleay River
• Manning River
• Shoalhaven River

Note that prioritisation results between individual floodplains are not directly comparable.