Table 14. 



Tidal prisms at Sabine Lake and 

 Port Arthur Canal entrances. 



Date 



Tidal phase 



. . 



Tidal prism (ft 



^ X 108) 



Lake entrance 



Canal 



1974 1 



10 Sept. 



Flood 





1 3.53 



1.71 





Ebb 





2.74 



1.74 



10-11 Sept. 



Flood 





2.55 



1.44 



11 Sept. 



Ebb 





3.36 



1.68 



11-12, Sept. 



Flood 





2.65 



1.88 



1975 1 



22 July 



Flood 





2.69 



1.74 



22-23 July 



Ebb 





4.40 



1.60 



23 July 



Flood 





2.35 



1.74 





Ebb 





1.18 









Flood 





0.53 







23-24 July 



Ebb 





2.52 



1.18 



24 July 



Flood 





2.46 









Ebb 





1.00 









Qp 





2.79 



1.70 





Qe 





3.55 



1.55 



of 0.44. For Sabine Pass, the most difficult parameter to determine was the 

 friction factor, f. Substituting the values listed below into equation (1) 

 gave an f value of 0.0145 (n = 0.018), which is considerably lower than the 

 previously assumed value of 0.025 but may be realistic due to the mud bottom 

 at Sabine. 



Ac 



= 



35,250 square feet 



h 



= 



2.6 X 10^ square feet 



L 



= 



43,000 feet 



R 



= 



17.6 feet 



T 



= 



89,000 seconds 



Letting the minimum inlet width remain constant (i.e., letting R vary 

 directly with A ), values of maximum average velocity and cross-sectional area 

 are plotted in Figure 82 for various deposition lengths. Note that the 1962 

 area and velocity plot very close to the locus of critical A 's for a depo- 



sition length about three-fourths the actual length, and that V^ 

 3 feet per second at the critical area. 



is about 



Comparing Sabine Pass to Jarrett's (1976) stability relationship for other 

 dual-jettied inlets, A^ = 3.76 x 10~^ P, the predicted equilibrium area is 

 26,917 square feet. This equilibrium area is probably close to that of the 

 original unjettied entrance, but less than the present area and the critical 



89 



