(2) Data Analysis and Results. 



(a) Tidal Ranges and Levels . Table 10 summarizes the available 

 information on tidal ranges throughout the inlet-bay system. Long-term aver- 

 ages indicate that the tidal range at the Sabine Pass southwest jetty is about 

 95 percent of the range at the Galveston Pleasure Pier, and that the pier 

 range is reduced another 10 percent midway through the pass. At Mesquite 

 Point, the entrance to Sabine Lake, the tidal range during the short period 

 record was about half that of the range at the jetty. However, long-term 

 averages from other gages indicate that the Mesquite Point range usually 

 exceeds 60 percent of the jetty range. 





Table 10. Tidal ranges. 



Sabine 



Pass, Texas. 







Date 





Location and gage 





Diurnal 

 range 



Ratio of ranges | 



Pier 



Jetty 



Pass 











(ft) 









1936 





Port Arthur (SWG) 





0.94 















June 19 60- Apr. 



1961 



Galveston Pleasure Pier 



(NOS) 



2.01 



1.0 











(excluding Jan 



) 



Jetty (NOS) 





2.30 



1.14 



1.0 











Pass (NOS) 





1.80 



0.90 



0.78 



1.0 



23 July-9 Aug. 



1962 



Galveston Pleasure Pier 



(NOS) 



2.12 



1.0 















Jetty (NOS) 





1.95 



0.92 



1.0 











Pass (NOS) 





1.54 



0.73 



0.79 



1.0 







Port Arthur (SWG) 





0.83 



0.39 



0.43 



0.54 







Mesquite Point v,NOS) 





1.03 



0.49 



0.53 



0.67 



Mar. -Aug. 1973 





Galveston Pleasure Pier 



(NOS) 



2.27 



1.0 















Jetty (NOS) 





2.18 



0.96 



1.0 











Pass (NOS) 





1.90 



0.84 



0.87 



1.0 







Port Arthur (SWG) 





1.10 



0.43 



0.50 



0.58 







North Sabine Lake (SWG) 





0.91 



0.40 



0.42 



0.48 



1974 





Galveston Pleasure Pier 



(NOS) 



2.18 





















Pass (NOS) 





1.83 



0.86 











As shown previously in Figure 2, monthly tidal range variability at Sabine 

 Pass (NOS gage) closely aproximates that of other Texas locations. Incomplete 

 data for 1973 (Fig. 74) indicate that the Port Arthur and north Sabine Lake 

 gages respond similarly but differ in range characteristics from the NOS pass 

 gage. In 1936, the Port Arthur gage data exhibited a different pattern in 

 range variability (Fig. 75). Over the past 20 years, the pattern of annual 

 mean range variability at Sabine Pass has differed significantly from that at 

 Galveston and Freeport (Fig. 7). Thus, it appears that over the long term, 

 minor variations in tidal range are caused by differing local meteorological 

 conditions in the lake (wind, rainfall, etc.) rather than astronomical forces 

 on gulf tides. Both short- and long-term patterns of tide level variability 

 (Figs. 3, 4, and 76) are similar for all stations within the pass system. 



(b) Tidal Phases . Average phase lags were computed from avail- 

 able data for the NOS Sabine Pass and jetty gages and for the SWG Port Arthur 

 gage (Table 11). As expected, extremes occur at about the same times at the 

 jetties and in the pass, while at Port Arthur they occur much later. 



c. Tidal Hydraulics . 



(1) Tidal Currents . NOS made extensive current measurements at the 

 four ranges shown in Figure 73 between 17 and 22 July 1962. The data were 



