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 is now invited to share feedback on the options.

Background

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.

About the 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 is looking at options for managing the lake entrance, and parts of the foreshore within the entrance channel that are actively eroding. The study is considering a range of environmental, social, economic and cultural perspectives. The UNSW Water Research Laboratory (WRL) are the expert consultants doing the study. The study has been done in two stages.

Stage 1 - Initial work involved collecting data in and around the entrance and a literature review of the lake entrance and other similar lake systems. Over 50 possible management options were developed and reviewed to come up with a shortlist.

Stage 2 - We are currently in this stage. It has involved detailed assessment of the shortlisted options and now consultation with community.

Find out more

You can find out more by:

• Watching the video above which provides an overview of the Lake Entrance Options Study including the shortlist of options
• Reading the FAQs
• Reading the Summary (23 pages)
• Reading the Study Report and Appendices

Printed information will be available to view at;
Warilla Library - 8 Woolworths Ave, Warilla
Shellharbour City Library - 76 Cygnet Ave, Shellharbour City Centre
Customer Service, Civic Centre - 76 Cygnet Ave, Shellharbour City Centre

(External link)

You can also:

• Talk to Council staff and the consultants at one of our drop-in information sessions:
  • Warilla Barrack Point Surf Life Saving Club – Friday 29 November, 1.00 - 3.00pm
  • Windang Senior Citizens Centre – Saturday 30 November, 10.30am - 12.30pm

If you have any accessibility needs or require further support to attend a drop-in session, please call 02 4221 6111.

• Watch the online information session held on Wednesday 4 December

Provide your feedback

• Complete a short online survey.
• Complete a printed survey available at Warilla Library, Shellharbour City Library and Customer Service at the Civic Centre. Customer Service at the Civic Centre(External link)
• Email Letschat@shellharbour.nsw.gov.auLetschat@shellharbour.nsw.gov.auLetschat@shellharbour.nsw.gov.au(External link) (External link)

Please share your thoughts with us by 5pm, 20 December 2024.

We'd love to hear from a wide range of residents, visitors, lake users and stakeholders to find an option that best balances uses and value of Lake Illawarra. You can share what is important to you about the lake, and leave feedback about the specific management options below.

This is a list of key terms that are used in the reports, summaries and other materials relating to the Lake Illawarra Entrance Options Study. We’ve provided some plain English definitions and explanations for technical terms or abbreviations that may be new or unfamiliar.

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

Base case scenario – this refers to not doing anything at all to manage the lake entrance.

Bed armouring – this is the placement of rock on the channel bed to protect it from sand scour, erosion and deepening. It also helps to slow down tidal currents by providing friction.

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.

Fauna – animals including birds, fish and other marine life.

Fish passage - this is how well fish can move into and out of the channel, which is important for fish migration and movement between the ocean and the lake’s tributaries. It is impacted by barriers and strong tidal currents.

Flora – plants and plant communities like seagrasses, saltmarsh, swamp oak and floodplain forest.

Gate structures – weir gates are structures that can be lowered or raised to allow the flow of water through the weir. (Picture to the right, for indicative purposes only).

Groyne – is a rock barrier built perpendicular to a foreshore or bank to slow tidal currents. These structures do not extend the full length of the channel

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.

Lake entrance – where the lake meets the ocean.

Recreational safety - this is a measure of how safe the channel would be for activities like swimming, kayaking and paddle boarding. It depends on the speed of tidal currents moving through the channel.

Rock Weir – a weir is a rock barrier built across a channel to slow tidal currents and raise the water level slightly on the upstream side. (Picture to the right

, for indicative purposes only)

Sand nourishment – is the artificial placement of sand back on a scoured shore to replace what has been lost due to erosion or previous dredging.

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

Tidal currents - are the horizontal movement of water (like ocean currents) that occur with the rise and fall of the tide.

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.

Videos by NSW Government

This project is supported by Shellharbour City Council and Wollongong City Council with technical and financial assistance provided by the NSW Government through its Coastal Management Program.