The back barrier of the shoreline is defined by the MDMAP as the location where the tide and storm surges rarely reach, or the first major barrier, whichever comes first. This may include a vegetation line, cliff, dunes, or other barrier. Debris that accumulates within the back barrier should be counted separately from the main part of the beach. If the back of the shoreline is only a partial barrier, for example a patch of vegetation behind which there is more beach, then consider the main beach to be up to the first continuous barrier (include that vegetation patch and the area behind it).