Line C.2. The design berm elevation for the project was 6 ft above mean 

 low water (set at the 50-yr tide elevation). 



Line C.3. The depth of closure for the project area is estimated to be 8 ft 

 based on profile analysis in the area. 



Line D.l. There are no non-diffracting groins included in the simulation. 



Line E.l. One diffracting groin is included at grid cell 1. 



Line F.2. The bottom slope near the groins is 0.1. 



Line ¥3. The north groin was constructed to have low permeability. 



Lines F.4 and F.5. The value of the length of the diffracting groin at grid 

 cell 1 was taken from a survey of the area. 



Lines G.6 and G.7. Locations of the breakwaters are taken from the as- 

 built drawings of the project. 



Line G.9. Transmission coefficients for the breakwaters were initially 

 selected to be 0.10 to indicate low wave transmission. 



Data for the SHORL Tiles 



The shoreline position for the initial simulation was obtained from 

 shoreline surveys conducted on July 8, 1991. 



Data for the DEPTH file 



A depth file was not required because an external wave transmission model 

 was not used. 



Data for WAVES file 



Wave measurements for the site for the time interval between measured 

 shoreline positions were not available. Instead, a 1-year wave hindcast was 

 conducted for the period January 1, 1991, through December 31, 1991. This 

 hindcast was conducted using hourly wind data from the Baltimore/ 

 Washington International Airport, which is located about 19.5 miles northwest 

 of Bay Ridge. Waves were hindcast up to the breakwater locations using the 

 shallow-water wave equations in the Corps Automated Coastal Engineering 

 System (ACES) Program, Version 1.05. 



The result of this hindcast was a time series of offshore wave period, 

 height, and direction data for the period January 1 to December 31, 1991. As 



Appendix A Case Design Example of Detached Breakwater 



A19 



