May 1974: The Storm Of Storms
When was the last big swell you remember hitting our beaches? Was it the epic surf we had in March or the massive six metre waves in June 2007 that pushed the Pasha Bulker freighter onto Nobbys Beach in Newcastle? I will never forget a crazy storm in May 1997, when I watched the ‘temporary’ lifeguard shed at Tamarama* get tossed around and waves smashed into the Tama Café. The maximum recorded wave height a few kilometres offshore of Sydney was fourteen metres during that storm!
Both of these storms were caused by East Coast Cyclones, which are intense low-pressure systems that tend to form literally overnight in the Tasman Sea, just off our coast, and last for a few days. They are not uncommon and we can usually expect one to two bad ones each year, but it takes a certain amount of ‘perfect storm’ conditions to generate a particularly nasty one.
What does it mean for us? We lose our beaches is what it means! It’s not uncommon after big storms to see rocks exposed on the beach that you never knew existed. Remember that our beaches are only really a thin veneer of sand over what essentially is a buried rock platform. Huge storm waves are incredibly erosive and it may take years for the sand to return to the beaches. The height of the sand at Tamarama still hasn’t rebounded to pre-1997 storm levels.
As impressive as those East Coast Cyclones were, they still don’t compare to the storm of storms that walloped most of the NSW coastline in May 1974. During that storm, eight metre high waves hammered our beaches for several days and the net result was massive. Beaches were stripped bare of sand and widespread damage occurred to coastal structures up and down the coast. Buildings were destroyed or fell into the sea, car parks were carved into, and some beaches and dunes eroded back more than 100 meters. Even the Sydney Harbour and Botany Bay beaches weren’t spared.
The May 1974 storm was a real wake up call. It was the catalyst that spurred governments into trying to understand the characteristics and behaviour of waves, beaches and dunes in response to severe events. It really was the birth of coastal management and policy as we know it in Australia. The storm was also the motivation for installing a series of offshore wave rider buoys to monitor wave conditions along the New South Wales coast. As a result we now have some of the best local wave information in the world, which is easily accessible to the public**.
An impressive storm for sure, but will we see one like it again? Well, a storm that size is estimated to occur about once every 50 years. It’s now been 37 years so we’re almost due!
* There used to be an old wooden lifeguard stand at the base of the surf club steps that got torched one night in the mid 90s. It was replaced by a temporary metal demountable that ended up lasting about five years until the $200,000 modern tower was built. Waverley Council moves in mysterious ways.
** Google ‘Manly Hydraulics Laboratory’.
‘Dr Rip’s Essential Beach Book; everything you wanted to know about surf, sand and rips’ is now a bestseller and is available at all good book stores and online at www.scienceofthesurf.com.