Friday, 20 December 2019

Over the past 48 hours, a 30-tonne excavator, two nine tonne dump trucks and a bobcat were used to dig a channel, moving approximately 1000 tons of sand to the front of the Birdwood Park dune. The channel created was approximately 40m long and on average 8m wide and extended down to the rock platform below the sand.

Although not confident the entrance would remain open, Council undertook the works to try and flush the lagoon with seawater for the Christmas holiday break.

The last part of the channel was opened at approximately 2:30pm Tuesday and works continued to dig the channel for an additional hour to give the best chance of remaining open.

Despite best efforts, nature won out again as the ocean waves pushed sand into the channel and closed the entrance.

Due to the low water level of the lagoon in the current drought-like conditions, there was not sufficient flow of water to the ocean on the outgoing tide to remove the sand and maintain an open entrance. We will continue to monitor conditions over the summer but unfortunately, rain is needed to make a difference to any longer-term lagoon opening.

The community is encouraged to use the Narrabeen rock pool as an alternative until conditions improve.

Find out more about Narrabeen and other lagoon opening triggers, or review a more extensive list of FAQs.

Tuesday 17th December

With the Christmas holiday season upon us, Council has been exploring every option to open Narrabeen Lagoon for locals and visitors to enjoy. 

But as those who live nearby understand, opening the lagoon, and keeping it open, is a battle with nature as the ocean acts as a massive sand pump, pushing sand back in to block the lagoon entrance. Without significant rainfall to help outflows remove sand from the lagoon entrance, it’s a huge challenge to have it remain open. 

Council’s engineers have been surveying sand deposits over the last month and have found less build-up than expected. Works conducted in November have assisted to keep the build-up to a minimum and will help the lagoon stay open when we do have rain. (see November update below).

Given this, and the significant levels of community interest in having the lagoon open for the holidays, Council has taken the decision to attempt an opening this week.

This will allow the lagoon to be flushed with seawater, improving swimming conditions for the community.

However, given conditions remain the same as when the lagoon previously closed, it is unlikely the entrance will remain open for a long period, unless we get some significant rainfall. Fingers crossed!

Find out more about Narrabeen and other lagoon opening triggers, or review a more extensive list of FAQs.

Friday, 8 November 2019

The works to create a large channel across the entrance of the lagoon are now complete and the sand removed from the area.

These works will assist the natural process following rain – to open the lagoon and facilitate it to stay open longer.

We understand some in the community would like us to open the lagoon now. However our engineers tell us if we do so with the lagoon at the current water level, ocean swells will push sand back into the channel, quickly closing the lagoon again, making the recent works redundant and making it more difficult to try and open again.

With summer on its way we know people would like the lagoon open so our aim is to manage the lagoon in a way that will give us the best opportunity for it to remain open over the Christmas holiday period.

Our engineers are currently doing further assessments to inform any next steps including surveying sand deposits within the lagoon. This work may identify an opportunity to open the lagoon sooner.

And, as always, we are constantly monitoring lagoon water levels and have teams on standby should we need to undertake an emergency flood opening.

Find out more about Narrabeen and other lagoon opening triggers, or review a more extensive list of FAQs 

Monday, 28 October 2019

Narrabeen Lagoon is the largest lagoon in metropolitan Sydney. Managing the lagoon’s entrance and keeping it open as long as possible is complex and dependent on a number of conditions including ocean currents, the amount of sand at North Narrabeen Beach, rainfall levels and time since the last opening.

Despite Council conducting an excavation to open the lagoon in late 2018, the entrance of Narrabeen Lagoon recently closed. We are working with experts to determine the exact reasons for the closure but it is believed to be a combination of a very large accumulation of sand at North Narrabeen Beach and lack of rainfall.  

We are currently preparing to do further works so we can maximise how long the lagoon will stay open following the next significant rainfall.

The works will include clearing a large channel across the entrance berm and removing sand from the area. That way when it does rain and the water level rises, the lagoon can open to the ocean again. It will also give us the best chance of the lagoon remaining open for a longer period.

These works are expected to commence in the coming weeks, depending on rainfall and swell.

Council is constantly monitoring lagoon water levels and has teams on standby should it need to undertake an emergency flood opening before all the sand is moved out of the way.

Find out more about Narrabeen and other lagoon opening triggers, or review a more extensive list of FAQs.

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