depth). In addition, the high tide shore is a much greater distance from the 

 structures than the low tide shore. Both these factors will affect the 

 diffracted wave angle at the shore and the resultant beach planform. 

 Lakeview Park, Lorain, Ohio 



22. This project was completed in 1977 for the purpose of protecting a 

 park facility and providing a recreational beach. It consists of an 

 84,000-cu-m beach fill bordered by two terminal groins and fronted by a 

 rubble-mound breakwater divided into three segments (Figure 11). Each break- 

 water segment is 76 m long, and adjoining segments are separated by 50-m gaps. 

 The segments were constructed in an average water depth of 3.5 m and are lo- 

 cated 145 m from the original eroded shore with crest elevation at 1.8 m above 

 the long-term average water level for Lake Erie. These segmented structures 

 are relatively impermeable and overtopped infrequently. Beach fill displaced 

 the shoreline to an average position of 76 m landward of the structure where 

 the placed fill rapidly adjusted to a relatively stable morphology which has 

 an undular shape due to the breakwater effects. The salients do not reach the 

 structures, but the area behind them has shoaled substantially. In the first 

 five years after construction, approximately 2,500 cu m of sand was gained 

 annually. A substantial monitoring and evaluation program was initiated imme- 

 diately after construction and continued for five years. A reduced level of 

 monitoring still continues. Through this monitoring effort, much has been 

 learned about the rate and nature of sediment/structure interaction, which 

 will be the subject of a future report. A detailed description of the project 

 and its performance is presently available in Pope and Rowen (1983). 



Presque Isle, Pennsylvania 



23. At Presque Isle on Lake Erie, a segmented system of over 50 de- 

 tached breakwaters is planned to protect the shoreline and create recreational 

 beaches along an 1 1-km-long recurved sand spit. A test structure consisting 

 of three rubble-mound segments was completed in 1978. The segments are each 

 40 m long, with one gap 60 m wide and the other 90 m wide. The crest eleva- 

 tion is approximately 1.2 m above the long-term average lake level and the 

 water depth averages 1.0m. Fill was trucked in and the shoreline was ad- 

 vanced to a location between 45 and 60 m from the structures. The subsequent 

 shoreline evolution is displayed in Figures 12a-d. Note that the most 

 westerly structure (left side of photo) dominates the entrapment of the long- 

 shore drift, which moves mostly from west (left) to east (right). This 



22 



