S ea level rise also increases the risk of coastal areas to flooding. The higher the sea level, the higher the flood level of a storm. W ater supplies for human or agricultural consumption are also affected by sea level rise. A higher sea level can mean that salty water intrudes into underground coastal aquifers more often than if the sea level were lower. Also, salty water can intrude higher upstream in estuaries, where the salty water may enter industrial or agricultural water intakes.
Setbacks are zones along the coast which are at high risk of erosion.
Property owners may not build or may have restrictions on building within these zones. These zones are typically established for a certain time period into the future based on the current rate of erosion. The purpose of setbacks is to allow the natural features of coast such as dunes, beaches and wetlands to migrate landward as sea level rises. S etbacks, however, are unpopular with property owners because they impose restrictions. Therefore, some states have implemented a policy of rolling easements where owners may build but are required to remove a structure when it becomes threatened by an eroding shoreline.