-20 



SECTION A-A 



1- 



UJ 



K -25 



2 



1 -30 



^ -35 



—1 



HI 



-40 















S« -_ 



~~ — - — . 







^ * 





^'' 









100 



200 



300 400 

 DISTANCE IN FEET 



500 600 700 





1 1986 SURVEY 



1992 SURVEY 1995 SURVEY 1 











Figure 33. Cross sections through Area A, Section A-A for 1 986, 1 992, and 1 995 surveys 



-10 



h- 



UJ 



[i!-15 



z 



§-20 



u 



-J 



UJ 



-30 



C 





SECTION B-B 













^ — 



-">"'^' 



^ 



~—~ ' " 







100 



200 300 

 DISTANCE IN FEET 



400 



500 





1986 SURVEY 



- 1992 SURVEY - 



1995 SURVEY 













Figure 34. Cross sections through Area B, Section B-B for 1 986, 1 992, and 1 995 surveys 



The Jxily 1995 survey was more comprehensive than the August 1992 survey in 

 that it included more bathymetry inside the harbor. To determine changes as a result 

 of the opening between the detached breakwater and the shoreline, the July 1995 

 survey was compared to pre-breakwater conditions (September 1986 survey). 

 Contours of bathymetric changes in the lee of the eastern portion of the detached 

 breakwater were prepared. Data indicate accretion of 2.4 m (8 ft) in areas inside the 

 harbor between 1986 and 1995, as shown in Figure 38. 



In summary, since construction of breakwater improvements at St. Paul Harbor, 

 a scour hole initially formed at the head of the main breakwater extension similar to 

 the one at the head of the structure prior to improvements. The scour hole has 

 shifted in location somewhat, but has not imdermined the toe of the breakwater head 



42 



Chapter 2 Monitoring Program 



