Pittwater Life May 2022 Issue

OPEN, NOT SHUT CASE:
Narrabeen Lagoon sand clearing.
Council doubles down
on Lagoon entrance
News
Northern Beaches Council proposes to double the frequency
of its proactive, medium-term management of the
Narrabeen Lagoon entrance following initial community
feedback on its Draft Strategy.
Council’s executive summary of its Draft Strategy, detailed
at Council’s April meeting, recommends more regular sand removal
from the mouth of the lagoon as a mitigation measure for
flooding due to weather events.
Currently, the Council’s medium-term focus involves the periodic
removal of accumulated sand in the lagoon entrance and
transport to Collaroy-Narrabeen Beach for beach replenishment.
Lagoon entrance clearance operations have been undertaken
over the past 40 years, and have involved removing on average
30,000-50,000m3 of sand approximately every three to five
years.
The last major clearance occurred in December 2021.
The draft strategy noted 111 submissions from its community
consultation between 10 February 2021 and 28 March 2021.
The strategy recommends clearing the entrance more frequently
but with a reduced volume – noting that a clearance of
15,000m3 every two years had a similar economic cost as a clearance
of 40,000m3 every four years.
The strategy also recommends that mobile sand pumping (as
an alternative to trucking sand) be reviewed if lower cost pricing
became available from a contractor-delivered scheme rather than
Council purchasing pipes and pumps.
The reshaping and revegetation of the Birdwood Park Dune is
also recommended, to reduce the potential for movement of sand
into the Lagoon.
Regarding short-term management focus, the strategy recommends
continuing “the reactive management of the Lagoon
entrance and associated emergency response arrangements and
intelligence, to reduce immediate flood risk within the Lagoon/
surrounding areas, including emergency breakouts of the entrance
as required”.
Northern Beaches Mayor Michael Regan said Council had been
actively managing the entrance to the lagoon to reduce the risk
of flooding in the catchment, while working on its longer-term
management strategy.
“Fortunately, Council was able to complete the major sand
clearance operation before Christmas ahead of the huge amount
of rain that we’ve had in the first few months of this year,” he
said.
“It has been great to have a range of flood and coastal experts,
as well as the community, contribute to the draft long-term
strategy and fully investigate all the options and their respective
benefits, costs and potential environmental impacts.”
Mayor Regan said public exhibition of the draft Strategy
would commence soon. Submissions will be reviewed and
where appropriate incorporated into a revised final strategy.
The final strategy will then be presented to Council for its
consideration.
“I look forward to hearing more from the community as the
draft is exhibited for comment,” Cr Regan said. – Nigel Wall
18 MAY 2022
The Local Voice Since 1991