Many State and Local Government agencies have a hand in managing the lake. These include, but are not limited to,

• Wollongong City Council
• Shellharbour City Council
• Department of Crown Lands
• Department of Climate Change, Energy, the Environment and Water (DCCEEW)
• Transport for NSW

As there are multiple agencies involved, the Lake Illawarra Coast Management Program (Lake Illawarra CMP) was jointly developed to ensure a coordinated approach to management of the Lake into the future.

We also work closely with stakeholder groups such as the Lake Illawarra CMP Implementation Group (representatives from council, state government and the community) who provide advice and oversee actions. Other local community groups and community members also inform some of the decision making.

Lake Illawarra was previously known as an “Intermittently Closed and Open Lake and Lagoon” (ICOLL). These are lakes that naturally open or close to the ocean. There was widespread community concern about the deteriorating health of the lake, and a decision was made to permanently open the lake by the former Lake Illawarra Authority. At that time (in 2007), this was the preferred option to manage estuary health issues (such as poor water quality algae blooms and associated odours).

The Lake Illawarra Coastal Management Program (CMP) was created to protect and improve the lake over the next 10 years. It is a long-term strategy for the joint management of the Lake.

One of the actions in the CMP is:

• Investigate and finalise options to manage erosion and accretion changes in the entrance channel.

In 2021, we received funding from Department of Climate Change, Energy, the Environment and Water (formerly Department of Planning and Environment ) to review existing Lake Entrance conditions and impacts, and develop some options to manage these. This is currently being done by consultants UNSW Water Research Laboratory (WRL) through the Lake Illawarra Entrance Options Study.

UNSW Water Research Laboratory (WRL) have been working with Council on the Lake Illawarra Entrance Options Study.

Initial work involved collecting data in and around the entrance and a literature review of the lake entrance and other similar lake systems.

Then over 50 possible management options were developed and are being reviewed to come up with a shortlist.

Before we share the options, we will be testing them to see how they perform in addressing the problem, and any other impacts they would have. This means you'll be able to consider the good and bad points about each option.

Later this year we will invite the community to share their feedback on these options, and their local knowledge and experience of the lake.

Following on from community consultation, a report for the Lake Entrance Options Study will be produced. The final report will give us a clearer indication and /or recommendations of the possible options to pursue.

Once the preferred management options for the lake have been confirmed, the responsible agencies will work together on implementation, including seeking any funding required. This process may take several years for major entrance works. We will continue to keep the community updated on this project and how they can be involved.

We're looking at options that will address the impacts to the lake and surrounding areas. The options will be checked to make sure they:

• Are legally possible;
• Are environmentally sensible;
• Do not cause further harm;
• Are designed to manage foreshore and lake bed erosion;
• Consider the community’s current and future use of the space;
• Manage changes to the tides as well as the tidal flows including the amount and speed of water flowing through the entrance;
• Have upfront and ongoing costs that are manageable.

We’ll also look at a range of environmental, social, economic and cultural perspectives.

• Environmental – how these options will impact on the flora and fauna and natural habitats of the lake
• Social – how the community is able to use and access the lake
• Economic – how businesses and/or commercial interests may be affected by changes to the lake
• Cultural - how options can be designed to minimise impact on cultural sites and values around the lake and its foreshores.

We’ll continue working with the relevant state government agencies while working through the management options. Once all these steps are taken, we’ll ask you (the community) to provide feedback, followed by detailed investigation and design.

Detailed modelling will also occur to understand how the options will impact on tidal flows and reduce ongoing erosion.

The tidal range in the lake will keep increasing, meaning low tides will get lower and high tides will get higher. This will impact on both recreation (such as boating in areas that are already shallow), as well as increasing impacts from flooding of foreshores and infrastructure from higher water levels. Habitats like seagrass will no longer be able to grow in areas that become shallower, and foreshore habitat like saltmarsh will be inundated too often for vegetation to survive.

The speed of tidal flows will get faster and foreshore erosion along existing foreshore structures will worsen. Impact to foreshore structures and assets in or along the entrance will continue, requiring ongoing expensive upgrades to foreshore protection.

No, this is also happening on other estuaries in NSW that have had entrance structures installed including Wagonga Inlet at Narooma, Wallis Lake at Forster/Tuncurry and Lake Macquarie.

Windang Bridge crosses Lake Illawarra and is an important bridge connecting Wollongong and Shellharbour Local Government Areas.

Since the lake entrance was opened in 2007, there has been some impact to the bridge itself. Tidal changes and faster moving water through the entrance is affecting the bridge piers. To ensure the bridge remains stable, rocks have been placed from the northern abutment up to pier 11 (or approximately one third the length of the bridge) to stabilise these piers and protect against further erosion. Further work is planned to place rocks along the full length of the bridge.

Transport for NSW (TfNSW) will continue to inform the community about any works that need to be carried out. Keep up to date with more information here.

An important aspect of preparing the Lake Illawarra CMP was understanding the community uses and values of Lake Illawarra to identify as well as assess the threats to the lake, its uses and values. Extensive community consultation was undertaken 2015 – 2019 to help Councils gain an understanding and integrate this information into the CMP. Detailed information on this can be found in the Community Uses, Values, Threats and Opportunities of Lake Illawarra Report.