In a state beset by sea level rise and flooding, the Blue Acres program has bought out and demolished 1,200 properties that were repeatedly inundated, turning the properties into buffer zones and open spaces.By Emilie LounsberryMANVILLE, N.J.—Richard Onderko said he will never forget the terrifying Saturday morning back in 1971 when the water rose so swiftly at his childhood home here that he and his brother had to be rescued by boat as the torrential rain from the remnants of Hurricane Doria swept through the neighborhood.