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Mapping outflow events

Published 1 July 2021 Mapping subtidal habitats and monitoring coastal outflow events to quantify impacts on coastal and marine waters
content image Optimised natural colour image from Sentinel 2 satellite (European Union) of an outflow event on the NSW north coast 10 April 2022 showing sediment laden plumes discharging to the ocean.


From the river to the sea: measuring coastal outflows seeks to fill knowledge gaps on the effects of freshwater outflow events from NSW estuaries into our coastal environments.

Freshwater outflows and their associated processes play a vital role in delivering nutrients, carbon and other food to the coast that support our marine ecosystems and fisheries. Within these outflows sediment, fertilisers and pollution from both urban and rural catchments may be of concern.

Coastal scientists from the Department of Planning and Environment (DPE) and Griffith University are reviewing the scientific literature and developing a coastal ‘outflows’ conceptual model. This will help show stakeholders, including local communities, managers, and water users how each part of the connected system effects the other when an estuary discharges to the coast.

Additionally, a collaboration with CSIRO is using cloud computing and satellite imagery to examine the size, frequency and distribution of coastal outflows over the NSW coast during the past two decades. We can then understand how water quality varies from region to region, and estuary to estuary to assess the risk of these events on offshore reefs and water column biodiversity, helping inform related management actions.


Local government areas - City of Hawkesbury, City of Newcastle, City of Willoughby

Lead agency

Department of Planning and Environment – Environment and Heritage Group


  • Commonwealth Scientific and Industrial Research Organisation – Oceans and Atmosphere
  • Coastal and Marine Research Centre, Griffith University

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