The Use and Legal Significance of the Mean High Water Line in Coastal Boundary Mapping

The effect of unplanned and ill-conceived land use development on the coastal ecology has been well documented in recent years. Recognizing the need for more effective governmental control in this area, a number of state legislatures have enacted statutes to protect the coastal environment and encourage the orderly development of coastal resources. These efforts have received the support of the federal government as well.

Determination of coastal boundaries is essential to the development of an effective coastal zone management program. In general such boundaries represent the intersection of the shore with a particular tidal elevation. However, the demarcation of coastal boundaries is complicated by legal uncertainties. Moreover, the unavailability of accurate tidal data or the use of improper survey methods make the accurate location of the physical boundary line a difficult task in many cases.

This article will examine a number of physical and legal problems associated with coastal boundary determinations and offer some solutions within the framework of the legislative proposal which accompanies this discussion.