1 + b x (11) 



where 



a = 0.956, regression coefficient 

 b = 0.398, regression coefficient 

 tan 8 



X = 





 d = water depth at structure, d 



and 



Q t = Q (1 + C w ) (12) 



where Q t is the total overtopping rate per foot of structure in cubic 

 feet per second per foot. 



Flood Routing 



67. Since the final desired result at Roughans Point is the frequency 

 of the interior water levels, another computer code was developed to route 

 overtopping volumes through the Roughans Point interior. This flood routing 

 code used output from the water level modeling and overtopping rate calcula- 

 tions. Output from the flood routing consisted of the maximum stage calcu- 

 lated for each event. These maximum levels were used for input to generate 

 the stage-frequency curve, for the interior of Roughans Point. 



68. For this report the only source of flooding considered was from 

 wave overtopping. Runoff from rainfall was not considered. This will have an 

 effect on the resulting stage-frequency curve, especially at the lower return 

 periods. This contribution will be determined by NED. 



69. Outflows from the interior of Roughans Point result from several 

 sources: storm drainage, seepage, pumping, and overflow both into the ocean 

 over low wall sections and into other drainage areas over elevated roadways. 

 Proposed improvements, in addition to providing for reduced rates of overtop- 

 ping, also include increased storm drainage and pumping. Figure 33 contains a 



57 



