Wollongong and Shellharbour City Councils are working together with the NSW Government to assess options for the Lake Illawarra Entrance. The project, called the Lake Illawarra Entrance Options Study, is looking at options to manage the impacts and changes that have occurred around the lake entrance and lake entrance foreshore. The community will be invited to share their feedback on the options.


In 2007, Lake Illawarra was permanently opened, by building training walls where the lake meets the ocean (the entrance) by the former Lake Illawarra Authority. This was done to address several issues including water quality, odour, and algal blooms.

The permanent opening of the channel has led to some improvement in water quality but has created significant and unintended changes to the lake and its entrance channel.

The changes that have impacted the Lake include:

  • Increased erosion along the Windang foreshore.
  • Movement of sand underneath the Windang bridge piers and need for protection works.
  • The lake’s water level now constantly fluctuates with the ocean tides. This means the average water level has dropped, but the tidal range in the lake has increased and is projected to continue to increase for a long time.
  • Increasing tidal ranges within the lake that have led to impacts on key habitats including seagrass and saltmarsh.
  • Undermining of built assets such as jetties and boat ramps.

Tell me more about the Lake Illawarra Entrance Options Study:

In 2020, Shellharbour and Wollongong Council created a Coastal Management Program (CMP) for Lake Illawarra to coordinate its management among stakeholders. Through strategic direction and actions, The CMP aims to address threats to the lake's value and sustainability. The Lake Illawarra Entrance Options Study is an action under the ‘Manage the Entrance Channel (EC)’ strategy, one of nine management strategies identified.

The study will look at several options for managing the lake entrance, and parts of the foreshore within the entrance channel that are actively eroding. The study will also consider a range of environmental, social, economic and cultural perspectives.

The UNSW Water Research Laboratory (WRL) are the expert consultants doing the study.

You can find out more by:

  • reading the FAQs
  • viewing the videos about the impacts
  • reading the data compilation and findings of the depth survey that are part of the Study
  • reading about impacts of the permanent entrance in the Lake Illawarra Coastal Management Program documents.

Take part:

The Illawarra loves the lake! And not just us, but people who come to visit as well.

We know it’s a valued and important natural asset to our communities. When the Study has been completed, we’ll invite you to share feedback on a shortlist of recommended options. These options will be created using a decision-making framework based on the community values of the lake, and expert advice. Your input will help us define suitable options for managing the entrance.

If you want to receive updates about the Lake Illawarra Entrance Options Study, and be directly notified when engagement opens, please follow this page by clicking the yellow “follow” button at the top of the page.



Videos by NSW Government

Impacts on tidal range, infrastructure and seagrass

Impacts on the local fishing economy


Accretion - The accumulation of sediment, deposited by natural processes such as waves, tidal currents and/or littoral currents.

CMP - Coastal Management Programs (CMPs) provide strategic guidance to managing waterways and beaches to ensure that issues are dealt with in an integrated and coordinated way.

Erosion - The removal of sediment from land by natural processes such as waves, tidal currents and/or littoral currents.

Estuary - The section of a river affected by tidal activity where fresh water from the river mixes with saltwater from the ocean.

Habitat - the natural home or environment of an animal, plant, or other organism.

ICOLL - A coastal lake or lagoon that alternates between being open or closed to the ocean is known as an Intermittently Closed and Open Lake and Lagoon. ICOLLs are separated from the ocean by a sand beach barrier or berm. This entrance barrier forms and breaks down depending on the movement and redistribution of sand and sediments by waves, tides, flood flows and winds.

Scouring - Localised loss of soil often present around a foundation element.

Tidal range - The vertical (height) difference in height between consecutive high and low waters over a tidal cycle

Training walls - A wall, bank, or jetty built to confine and direct the flow of a river or tide.

This project is supported with funding from the NSW Government’s Coastal and Estuary Management Grant Program. In partnership with Shellharbour City Council and Wollongong City Council.