Miami Beach is “retrofitting 300 outflow valves that allow stormwater to drain into the bay, inserting plugs to prevent the reverse flow of sea water. Dunes are being reinforced with sea oats and engineers are looking into pumping water into underground storage.” (http://uk.reuters.com/article/2014/10/03/us-usa-miami-beach-flooding-idUKKCN0HS0U820141003)

Porridge has long been known to be as effective as concrete.