a species able to withstand frequent mowing was used. This type of 

 vegetation requires constant management. Unfortunately, not all soils 

 are adapted for this type of erosion control. Coarse sands are well 

 adapted, while silt and clay soils are not; their very fine particles 

 are easily moved by water. 



c. Vegetation in Combination with Structures . During the field 

 survey, three structures were observed that were successful, in com- 

 bination with vegetation, in controlling shoreline erosion. The 

 structures were located on Lakes Superior, Michigan, and Erie, and 

 were of three different types: riprap, seawall with groin, and jetty. 



Near the state highway at Herbster, Wisconsin, on Lake Superior, 

 riprap was installed to abate bank erosion. The riprap has stabilized 

 the bank against wave action; a well-established vegetative cover has 

 decreased the runoff rate. 



Another structure that is successful in controlling bank erosion 

 is a concrete seawall and groin at the Kenilworth, Illinois, Public 

 Water Works on Lake Michigan (Fig. 7) . Lake level increases here have 

 greatly reduced a private beach that fronted the seawall, but the wall 

 is very effective in dissipating wave energy. The dense and well- 

 established vegetation behind the wall successfully prevents surface 

 runoff erosion on the bank. 



On Lake Erie, at Ashtabula, Ohio, a jetty (Fig. 9) has effectively 

 dampened wave action so that a pool has formed between the shore and the 

 structure itself. The quieter pool area is a desirable habitat for 

 reed, which in turn provides aquatic habitat and enhances the aesthetic 

 quality of the shore. 



V. SUMMARY AND CONCLUSIONS 



Attempts to establish vegetation on the shores of the Great Lakes, 

 particularly Lakes Erie and Ontario, for erosion abatement are not ex- 

 pected to be successful without structural wave dampening, and often, 

 land reforming. After wave force has been reduced and the shoreline 

 stabilized by use of structural methods, vegetation can be established 

 to further stabilize the soil, and thus reduce surface erosion resulting 

 from runoff. If vegetation is to be established to dampen waves and to 

 limit inland wave penetration, some reforming to develop a gradual slope 

 of the foreshore is desirable and may be feasible in places. 



Establishment and maintenance of an effective vegetative cover on 

 sandy areas will require fertilizing and irrigating, and continuous 

 maintenance will be necessary. The vegetation selected must be com- 

 patible with the land use, particularly if the area has public access. 

 Before any attempt is made to stabilize the sand with vegetation, the 

 effect of seepage must be evaluated to determine if dewatering is 

 needed for a firm sand-clay interface. 



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