“You can have the beach, or the seawall, but not both.” Sydneysiders cling to the sea, but as sea levels rise and storms intensify, the big question is whether our most valuable properties will become worthless – and when? Angus Gordon )AM is an internationally experienced coastl engineer and a former CEO of Northern Beaches Council. He joins Elizabeth Farrelly tonight on THE SYDNEYIST, tonight at six to talk about the answer to this conundrum.