37 



5^. The results of the model tests indicated that both the Field 

 Point and Fox Point "barriers would provide complete protection to areas 

 upstream from the barrier sites^ since no overtopping of the structures 

 by hurricane tides occurred. The effects of these barriers on astronom- 

 ical and hurricane tide elevations throughout the bay system were 

 negligible. No significant buildup of hurricane tides downstream from 

 the barrier sites occurred for conditions of either of the hurricane 

 tides tested. Elevations observed downstream from the Field Point, bar- 

 rier (plan 28) were slightly lower for the plan tests than for the base 

 tests; however^ this small reduction in elevation was caused by the 

 absence of the discharge of the Seekonk River during the tests of this 

 structure (the discharge was introduced during the base tests, but pro- 

 visions for pumping the discharge over the structure were not provided 

 in the plan tests, so the inflow weir on the Seekonk River was cut off 

 for the plan tests). The Fox Point barrier tests were not affected by 

 river discharge since this barrier was located upstream from the mouth 

 of the Seekonk River. 



55- Evaluation of the two upper Bay barriers showed that the Fox 

 Point barrier would not only afford protection to the critical portions 

 of Providence in which maximum damage has been caused by hurricane tides 

 of record but would also be much less costly than the Field Point bar- 

 rier because of the much greater width of channel and the need for naviga- 

 tion facilities at this latter site. The Fox Point barrier was therefore 

 selected for testing in combination with Lower Bay barrier plans. 



Combination Barrier Plans 



Preliminary combination barrier plans 



56. A total of five preliminary combination barrier plans (plans 

 30 through 3^) were proposed for testing in the model to determine the 

 effects of size of navigation openings in the East and West Passages 

 on astronomical and hurricane tide elevations throughout the bay system. 

 All of these plans incorporated the Fox Point barrier in addition to 

 Lower Bay structures at the locations of those of plan 29, described in 



