Table 10 

 Wind Contribution to Overtopping 















Q(total) 

 cfs/ft 





Procedure 



Q(OT)* 



SPM** 



Resiot 



7,0 Swl 



0.148 

 0.360 

 0.310 



8.0 Swl 



0.480 

 1.070 

 0.830 



9.5 Swl 



0.793 

 1.790 

 1.050 



* Q(total) measured from Phase II model tests 



(cfs/ft), for a +1 NGVD elevation beach; does not 



include wind-induced contribution. 

 ** Q(total) = Q(OT) + Q(wind) as calculated using the 



SPM method. 

 t Q(total) = Q(OT) X (1 + k') (paragraph 40) where 



k'= 1.09 for 7.0 swl, 0.73 for 8.0 swl, and 0.33 for 



9.5 swl. 



overtopping for the +8.0 swl. However, with no data to verify or dispute 

 estimates from any method, there is no factual basis to recommend one type of 

 adjustment over another. 



52. As a result of the physical model tests, the stone toe protection 

 was evaluated for its role in reducing overtopping and providing scour protec- 

 tion. Based on observations made during the model tests at lower swl's the 

 riprap appeared to reduce overtopping. However, at the higher swl's the rip- 

 rap did not reduce overtopping. Actual values were never calculated because 

 model tests were not run without the stone toe protection. 



53. The riprap was originally included to control scour at the base of 

 the seawall, thus reducing the risk of structure undermining. However, in 

 light of the proposed structure design, which includes vertical steel sheet 

 pile to a depth sufficient to assure protection of the seawall base in spite 

 of the expected toe scour and the proposed pile support system for the 

 seawall, the stone toe protection is not required. The design and cost of the 

 structure may warrant its removal from the final design. 



33 



