Local Councils Rise Sea Level Challenge

By Ben Graham on October 31, 2013 in News

Photo: Brad Bessant

The threat of climate change and its link to rising sea levels has prompted councils and scientists to consider ways of protecting our iconic beaches from gradually shrinking.

The sea level is expected to rise by up to 80 centimetres by the end of the century with a rise of 20 centimetres as the best-case scenario according to the latest report from the Intergovernmental Panel on Climate Change.

Doctor Rob Brander, a coastal scientist at UNSW and former Beast contributor, said that the news is worrying because beaches in urban areas such as the Eastern Suburbs are at the most risk from climate change.

“Naturally, with rising sea levels, untouched beaches migrate landwards so they’ll be fine. But it’s when you start to build around beaches that the problems start. The developments block off the beach’s natural landward shift and so the sandy area will get smaller and smaller.

“That said, to say we’re going to lose Bondi Beach, for example, is a bit misleading because an 80 centimetre rise is the absolute worst case scenario and there are a lot of things we can do to mitigate the damage,” Dr Brander said.

Mayor of Waverley Council, Sally Betts, said the council takes the IPCC results very seriously and that they are also aware of the need to prepare for the impacts of climate change and prepare for the worst-case scenario.

“We regularly monitor our other sea walls to ensure their structural integrity. Council staff closely monitor storms and high rainfall events, and we have an engaged community able to provide regular feedback on any changes to our coastline,” Cr Betts said.

But Cr Betts said that, compared to other Sydney beaches and the NSW coastline, in general Waverley is in a relatively good situation due to its high cliffs and sea walls, which are well above the high tide mark, making the risk of coastal inundation and sea level rise to the beaches low.

“In the very long term, beach nourishment is possible to maintain our beaches, and something other councils in Sydney already have to do. Waverley has never needed to do this and our study showed we should be able to avoid beach nourishment for a very long time,” Cr Betts said.

Dr Brander said that nourishing the beaches with sand that has been dredged from offshore locations is an option to lessen the impact of rising sea levels, but he also said it can be problematic.

“The flip-side of this process is that, over time, it’s going to cost a lot of money because when you get a storm, you can lose all that sand. So it will be this constant process of nourishment and re-nourishment,” Dr Brander said.

A spokesperson for Randwick City Council said that the risk to the Randwick coastline was also relatively low.

“The council has been incorporating climate change risk into our planning and development controls and our infrastructure management, as well as our community information and emergency management regimes, for some years now.

“Our long-term plans and policies incorporate planning for climate change risk, and our current development controls and floodplain management processes are in place to plan for and prepare for the impacts of increased storm events or flooding which may occur across our catchments or sub-catchments,” the spokesperson said.

John Conner, CEO of The Climate Institute, said that the increased likelihood and severity of storms due to climate change combined with the rise in sea levels is a serious cause for concern.

“It’s not just the small increments that matter, it’s what happens when these combine, as Superstorm Sandy did, with king tides and mixed storm surges. That’s when you get the double and triple whammies of these impacts,” Mr Connor said.