To mitigate the risk of flooding in new lower ground development from high lake levels (which has happened in the past). Even though lake levels are low now, they do fluctuate each year. I recall just a few years ago water running across the existing road into the stores, especially with strong winds off the bay. Council at that time decided to leave sand over the road to expand the beach and build a retaining wall along the sidewalk in front of the stores. The sand and wall were removed about 2-3 years ago to allow vehicles to drive along it again (until it closed again with this summer's construction of the new road). With the new builds they don't want any risk - there will be a retaining wall built along the beach with access from many points.