ACTION or no action - that will be the decision Port Macquarie-Hastings councillors will make on the lake at Lake Cathie when they meet on Wednesday night (May 20).
Crown Lands, on May 11, granted Port Macquarie-Hastings Council conditional approval to open the ailing waterway at Lake Cathie in the event of flooding.
Further consultation with the Department of Primary Industries - Fisheries (DPI) and National Parks and Wildlife Service (NPWS), at the the request of Crown Lands, has now presented council with another option - scrape the sand berm back to 1.6m, rather than dig a channel, at the lake entrance.
This is management option is more environmentally sensitive and preferred by DPI and NPWS.
"DPI Fisheries has some concerns about the potential adverse ecological impacts of the current proposal (to excavate a channel)," DPI-Fisheries advised.
"Artificial entrance openings of ICOLLs, such as that proposed in Lake Cathie, can lead to immediate, unintended ecological impacts such as large scale fish kills.
"In addition, poorly timed artificial openings, such as those occurring before periods of drought, can cause long term low-level, hyper-saline, high temperature water which can also contribute to adverse ecological impacts such as fish kills and habitat loss."
A council spokesperson said councillors will now consider three options at the May meeting - use Crown Lands' approval to open the lake by digging a channel to 0.8m; follow the environmental considerations of DPI and NPWS and scrape the sand berm (dune) back to 1.6m; or do nothing.
It has also been recommended that council write to the Minister for Water, Property and Housing confirming that council's ongoing responsibilities for management of the Crown-owned Lake Cathie waterbody will be strictly limited to the responsibilities of flood mitigation, stormwater drainage and community protection only and any actions outside of this scope will be directed to the NSW Department of Planning, Industry and Environment - Crown Lands as the owner of the waterbody.
Saving Lake Cathie spokesperson Stewart Cooper said the most beneficial outcomes need to be a priority when making a final decision.
"One of the big issues is if they go with the scraping, which I agree with as a short term solution as it minimises risks, you have the lake maintained at around 1.6m AHD which looks good, but it remains fresh water and it does not resolve the flooding at Aqua Reserve nor the flooding in residents' backyards," Mr Cooper said.
"Opening up a channel runs the risk of a significant reduction in water levels due to the siltation in the system. It also has a high risk of exposing acid sulfate soils again.
"Positive outcomes would be reducing the water level at Aqua Reserve and residents' back yards."
Under the short term licence, council is permitted to enter the land for the purpose of emergency opening works, in the event of flooding only, during the next 12 months.
The lake height as of May 18 at 4.45am following some rain, reached 1.599m. The trigger point for an emergency opening is 1.6m.
The push for a short term licence led by mayor Peta Pinson in November 2019 was initially thwarted when Crown Lands came back to council and indicated its lake data was more than two decades old and required updating.
The Crown Lands approval was fast-tracked last week following a council decision on May 6 that provided the community assurances the lake and its future was a priority. Council also provided Crown Lands with updated environmental data.
Port Macquarie-Hastings Council's May 20 meeting commences at 5.30pm and will be live-streamed via council's YouTube channel.