GUIDELINES FOR MONITORING SHORE PROTECTION STRUCTURES 

 IN THE GREAT LAKES 



I. INTRODUCTION 



In recent years increased rates o£ shore erosion in the Great Lakes 

 have resulted from unusually high water levels, although erosion may 

 continue at any level of the lakes (Berg, 1965) . Erosion is especially 

 critical where the shore is characterized by narrow beaches backed by 

 bluffs or high dunes. Landslides often result on this type of shore 

 when high waves, caused by storms over the lake, attack the base of 

 bluffs or dunes. The landslide material that falls onto the beach or 

 .nto the water is then attacked by the waves; since most of this 

 material is generally fine it is moved offshore and alongshore, out of 

 the area. An irretrievable loss of consolidated land results and 

 potential loss of buildings and associated development is threatened. 



If the loss of land is too costly or the shoreline is retreating too 

 fast, it may be necessary to install some type of shore protection 

 structure to prevent complete loss of upland development. The Coastal 

 Engineering Research Center (CERC) has published a comprehensive manual 

 concerned with designing coastal structures for shore stabilization or 

 navigation improvement (U.S. Army, Corps of Engineers, Coastal Engi- 

 neering Research Center, 1973). 



Alternative shore protection methods for a given problem are presented 

 along with construction guidelines in a Help Yourself brochure recently 

 published by the U.S. Army Engineer Division, North Central-'-. 



Since the extent of damage caused by waves is difficult to predict, 

 it is advisable to monitor the behavior of the lakeshore after construc- 

 tion of a protective structure. In this way the effectiveness of the 

 shore protection can be determined. To ensure best results from a 

 monitoring program, the method used to determine erosion rates and per- 

 formance of the protective structure must be systematic. These guide- 

 lines provide methods for determining changes in location of the shore 

 and bluff, and for analyzing the effectiveness of various types of 

 structures which may be installed. The guidelines are intended for use 

 by city, county, and State agencies in setting up and managing data 

 collection on the behavior of shore erosion control structures. A 

 glossary of terms is included in Appendix A. 



II. METHOD^ FOR RECORDING SHORELINE CHANGES 



An optimum program for recording shoreline changes is to survey 

 profiles near property lines and at the center of the property using 

 standard surveying techniques (Allen, 1931; Ruby, Lommel, and Todd, 1950; 



This brochure may be obtained free of charge by writing to: Department 

 of the Army, North Central Division, Corps of Engineers, 536 S. Clark 

 Street, Chicago, Illinois 60605. 



