Mrs Williams made the comments during a speech to parliament on the Coastal Management Amendment Bill 2021, advising council to consider dredging the lagoon.

During a speech to Parliament on the Coastal Management Amendment Bill 2021, Mrs Williams said the Bill aims to amend the Coastal Management Act 2016. This will enable certified Coastal Zone Management Plans to remain in force to 31 December 2023.

This means Port Macquarie-Hastings Council will be able to continue to implement actions in their Lake Cathie Coastal Zone Management Plan, Mrs Williams said.

"These actions include providing community opportunities to enjoy our natural environment through reserve improvements, continuing public access, periodically dredging of Lake Cathie entrance and beach nourishment," Mrs Williams said.

"In November 2020, I wrote to the then acting general manager of Port Macquarie-Hastings Council Jeffrey Sharp asking that council give consideration to dredging the lagoon in the coming months for the purpose of beach nourishment on Illaroo Road.

"As well as replacing recent sand loss on the fore-dunes, this action would also provide the benefit of increasing the water depth within the lagoon which I believe would be advantageous during predicted heavy rainfall events expected during the summer months.

"The enhanced water volume within the lagoon would also likely have positive impacts on the next lake opening which of course many residents will be hoping for prior to the upcoming Christmas holiday season.

"That was last year and now again, given the very similar scenario of the lagoon being now closed, I ask that council again give consideration to dredging of the lagoon."

Her call echoes those of community advocacy group Revive Lake Cathie who also called for a pre-Christmas lake opening.

Council said it is committed to its floodwater trigger point plan for the waterway.

The lake has all but closed at the entrance after being manually opened in January 2021 under Port Macquarie-Hastings Council's short term licence for flood mitigation intervention.

Mrs Williams said council's Lake Cathie Coastal Zone Management Plan (CZMP) proposes that council will continue to undertake periodic dredging of Lake Cathie lagoon and to place dredged/.excavated sand from the Lake Cathie entrance on the beach adjacent to Illaroo Road.

As an indication of the volume of sand that may be available in the Lake Cathie entrance, approximately 25,000 cubic metres was removed in 2005 and ongoing in 2014, Mrs Williams said.

"The coastline around Lake Cathie is particularly exposed to coastal hazards that threaten private and public assets. Significant coastal erosion has occurred south of the Lake Cathie entrance along Illaroo Road and the impacts have been clearly documented over the past decade," Mrs Williams said.

"I want to take this opportunity to acknowledge the work of both the Lake Cathie Progress Association and Revive Lake Cathie for their strong focus on the health of the lake which is in the best interest of the environment and the community."

Mrs Williams also acknowledged residents who were involved in the development of the Lake Cathie Community Plan and particularly those in the Community-Council Action Team (CCAT) which was formed to assist with the development of the community plan.

The Lake Cathie CZMP incorporates a revetment wall and beach nourishment as the management option in particular for Illaroo Road and will guide the management of the Lake Cathie foreshore into the future to ensure the most beneficial outcome for all stakeholders.

Mrs Williams said she will have more to say on the Lake Cathie revetment wall closer to the local government elections on December 4.

Deputy Mayor Lisa Intemann is also supporting the call for council to dredge Lake Cathie.

"I congratulate the Hon Leslie Williams MP for her success last week in amending the Coastal Management Act 2016," Cr Intemann said.

"That means the existing Lake Cathie Coastal Zone Management Plan stays in force for another two years, permitting dredging of the lake and the sand moved to protect the beach.

"I urge council to undertake this action sooner rather than later, while the lake is still closed."

Cr Intemann said she does not support artificial opening of the lake at this time.

"While we would all like to see the lake open, the lake system is still very vulnerable," she said.

"Current advice from Southern Cross University advises that a mechanical opening, at this time, risks having a detrimental impact.

"We should dredge now, while the lake is calm and closed.

"Locate the dredging both so as to help not hinder the lake as regards the preferred break-out point for when the lake does re-open, and to minimise any potential impact on acid sulphate soils."

Council director of infrastructure services Melissa Watkins responded earlier this month to calls for an artificial lake opening.

She said the lake, as an intermittently closed and open lake and lagoon (ICOLL), will naturally alternate between being open and closed to the ocean because of the sand berm at the entrance and catchment inflows from prolonged rainfall.

"Port Macquarie-Hastings Council undertakes artificial intermittent openings and closing of Lake Cathie to mitigate flood risks, only," Ms Watkins reaffirmed.

"The current trigger for proceeding with an artificial opening is when the lake level exceeds 1.6 metres AHD. At this level, council will undertake works to lower the level of the sand berm to facilitate a natural opening in accordance with the requirements placed on the licence issued by NSW DPIE-Crown Lands, the owner of the waterbody.

"Current advice from Professor Scott Johnston at Southern Cross University is that the lake is still recovering from the impacts of the extreme drought in 2019 on acid sulfate soils. Recent research by Southern Cross University has found shallow groundwater on the edges of the lake channels have very high levels of dissolved iron."

Ms Watkins said residents must understand that any artificial opening of the lake to the ocean often leads to a rapid drop in lake water levels.

"If that were to happen now, it would risk causing some of that iron-rich water to seep into the lake, potentially triggering another mass iron floc event, similar to what happened in 2020," she explained.

"Council is currently working on a long-term holistic plan, known as the Coastal Management Program (CMP), for the Lake Cathie/Lake Innes estuarine system by actively engaging with stakeholders, including the community, universities and State Government to understand the system and the impacts of long term management decisions."

Stage 2 (risks and opportunities) of the Lake Cathie and Bonny Hills CMP is expected to be completed in 2022, Stage 3-4 (evaluate and adopt) in 2023 and Stage 5 (implementation ) from 2025 and beyond.

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