establish boundaries that are generally recognizable and administrable and 
can be identified clearly on a map. However, property owners should not be 
deprived of riparian rights through arbitrary delineations. Within the coastal 
zone there are three lines that affect riparian rights along the shore. These 
are the upper wetland boundary, the mean high water line, and the mean low 
water line. Over the course of several centuries, English law has recognized 
the ordinary high water mark as the usual boundary between public and private 
property. Several American colonies adopted the law, and the high water line 
is recognized in Alabama, Alaska, California, Connecticut, Florida, Maryland, 
Mississippi, New Jersey, New York, North Carolina, Oregon, Rhode Island, South 
Carolina, and Washington. Massachusetts and Maine adopted a colonial ordinance 
and now use the low water line. Delaware, Georgia, New Hampshire, Pennsylvania, 
and Virginia also recognize the low water line as the boundary between public 
and private land. Texas recognizes the high water line for common law grants, 
but when Spanish or Mexican grants are involved, the line of higher high tide 
is used. Louisiana adopted the line of highest winter tide, and in Hawaii 
private property ends at the upper reach of the wash of the waves. 
The upper wetland boundary is a physiographic and biological feature, 
and only by coincidence would it be in the same position as a property boundary. 
Knowledge of the position is important for regulatory activities. Dredge and 
fill operations are generally prohibited in the wetlands unless a permit is 
obtained. The authority of the U.S. Army Corps of Engineers has been expanded 
under Section 404 of the Federal Water Pollution Control Act of 1972 to regulate 
dredge and fill activity above mean high water. They had previously restricted 
their authority to navigable waters, which under the River and Harbor Act of 
1899 were understood to extend to the mean high water line. A phased program 
of expanded regulations from 1975 to 1977 will result in Corps permits being 
required for discharge of dredged or fill material not only in saline coastal 
wetlands but in wetlands along major rivers and small tributaries if the average 
flow is greater than 5 cubic feet per second. Lakes larger than 5 acres will 
also be regulated. 
The statutes of many States include references to tidal influence, map 
contours, and vegetation characteristics of the wetlands. The relatively 
small number of species of indigenous vegetation that grow in saline or 
brackish conditions--usually & dozen will cover most localities--is quite 
useful as a reliable indicator of tidal influence. Sapelo Island off the 
coast of Georgia was selected by USGS to pursue the research objectives of 
investigating coastal wetland mapping procedures and evaluating accuracy, 
time, and costs. The site contains large areas of typical marsh vegetation 
and some complicated transition zones. The tidal range is generally greater 
than along most of the east or gulf coasts and averages 7 feet. The University 
of Georgia has a Marine Institute on the island which has accumulated consider- 
able background data on the region.