The Coastal Zone 



Erosion is a common and often severe form of degradation of the coasts, 

 caused by the action of tides, currents, and hurricane-induced stonn surges 

 and frequently aggravated by man's misuse of coastal lands. As a conse- 

 quence, vast areas of valuable land have been essentially lost. Erosion may 

 also introduce pollutants into the water, and the material deposited may 

 clog navigation channels and suffocate marine life. Similarly, dredging for 

 navigation is essential to waterborne commerce but can damage environ- 

 mental quality — disturbing the habitat of marine or marsh life and affecting 

 tidal circulation. 



These deleterious effects can be controlled somewhat by shore stabilization 

 and protection and by careful planning for channel and harbor construction, 

 maintenance, and removal of hazards to navigation — long established func- 

 tions of the Corps of Engineers. Traditionally, coastal engineering projects 

 have been authorized and carried out one at a time in response to local 

 requests. Recently, however, the Corps has adopted a longer- range approach 

 to setting priorities for such public works. 



The 1968 River and Harbor Act (P.L. 90-483) authorized the Corps to 

 make a study of U.S. coasts to identify areas where erosion presents a serious 

 problem, describe suitable remedial action, including preliminary cost esti- 

 mates and priorities, and provide State and local authorities with informa- 

 tion and recommendations concerning land use. 



Research in tidal hydraulics seeks an understanding of the fundamentals 

 of tidal circulation in estuaries, movement of sediments, and the physical 

 effects of natural and structural changes. These conditions, such as the 

 shoaling of an inlet and consequent reduced salinity of bay waters, cause 

 drastic changes in estuarine ecosystems. 



In addition to its own engineering programs, the Corps issues permits 

 for private construction in navigable waters. Its original regulatory authority 

 to protect navigation has been expanded to consider other possibly adverse 

 environmental effects— through the Fish and Wildlife Coordination Act 

 and subsequent interagency agreements with the Department of the In- 

 terior. This expanded authority is now being tested in the Federal courts. 

 Should the courts find that Corps permits cannot be denied on grounds 

 other than hazards to navigation, consideration of legislation to protect 

 broader public interests may be warranted. 



During the past year the Council endorsed a FY 1970 initiative of 

 the Corps of Engineers, in cooperation with the Department of the Interior 

 and other agencies, to expand efforts to assess the impact of water-related 

 construction activities on coastal ecology. At the same time the Corps will 

 accelerate its research efforts to develop new techniques and equipment for 

 restoration of coastal shores, including more economical systems for movmg 

 offshore sand onto beaches. Figure IV-4 shows the results of one beach 

 restoration project. 



71 



