Introduction
Delaware's beaches are a valuable natural resource. They offer recreational and economic opportunities as well as protection from storms. They also provide habitat for migratory shorebirds. Beaches are dynamic, changing shape in response to winds, waves, currents and tides. Storm driven ocean waves pound the shore causing erosion and deposition of sand in offshore bars and/or inland as overwash deposits.
During fair weather, milder waves gradually move sand bars back onto the beach. Winds transport and deposit sand inland, building new dunes. While the beach usually regains its pre-storm shape, some sand may be lost from the system. If this natural movement is blocked by obstacles such as man-made walls, a beach can be lost entirely.
Coastal development adds stress to beach systems, especially dunes. Dunes are sand storage areas which supply the beach during storms. Ironically, it is often those structures which damage or destroy the protective ability of the dune which rely most on the protection of the dunes during storms. 
If coastal development is not managed with respect for the dynamic nature of coastal dunes, storms may cause serious property damage and threaten lives. Increased erosion and vulnerability may also cause significant economic impacts to individuals, businesses, and State and local governments.
Regulatory Authority
Recognizing the need to enhance, preserve and protect public and private beaches and to insure their use as protective and recreational lands, the Delaware Legislature passed the Beach Preservation Act (Chapter 68, Title 7 of the Delaware Code) in 1972.
The act defines the beach as the area extending from the Mean High Water line of the Atlantic Ocean and Delaware Bay seaward 2,500 feet, and landward 1,000 feet and from the Delaware/Maryland line at Fenwick Island to the Old Marina Canal north of Pickering Beach.
To ensure that beaches and dunes are able to perform their protective and recreational functions, construction must be kept off them. A Building Line has been established along the coast as part of the Regulations Governing Beach Protection and the Use of Beaches. The Building Line, which parallels the coastline, is designated on DNREC maps. No construction may take place seaward of the Line without a Coastal Construction Permit or Coastal Construction Letter of Approval from the Department.
