Table 1 



Cordova Small-Boat Harbor 



Cordova, Alaska 



Date(s) Construction and Rehabilitation History 



1935 The small-boat basin was authorized. 



1938 The project was completed, including 8.26 acres dredged to -10 ft 



mllw; and a 1,100-ft north breakwater and a 1,400-ft south breakwater 

 were constructed. 



1964 The area was uplifted 6.4 ft in an earthquake. Expansion was 

 authorized. 



1964- The basin was rehabilitated by repairing and strengthening break- 



1965 waters, constructing an access road along the crest of the north 

 breakwater, and dredging the basin plus an additional 10.4 acres to 

 -14 ft mllw. 



1966 An entrance breakwater was constructed. The harbor at this stage is 

 shown in Figure 4. 



1981 Expansion was authorized. 



I98I- The basin was expanded by 19.55 acres by removal of the 1,400-ft 

 1983 south breakwater, construction of a 650-ft extension to the existing 

 silt barrier breakwater, and construction of a 1,902-ft rubble-mound 

 breakwater. A rubble-mound breakwater was constructed to crest 

 elevation of +21.5 ft mllw, crest width of 7 ft, and side slopes of 

 1:1.5. The breakwater was constructed of a 2-ft-thick bedding layer 

 of rock spall, a core of Class "B" rock, and a 4.5-ft-thick layer of 

 Class "A" armor rock extending to 1.5 wave heights below low tide on 

 the north section of the breakwater and to the tidal flats on the 

 other sections. The silt barrier breakwater was constructed of a 

 2-ft-thick underlayer of rock spall, a core of rock spall, and a 

 protective layer of Class "B" rock. Cross sections of the break- 

 waters are shown in Figure 5. The basin extension was dredged by 

 local interests to -12 to -16 ft mllw; the Corps deepened the 

 entrance channel to -16 ft mllw. 



The design wave was 5.6 ft. Class "A" armor rock was 900 to 1,500 lb 

 with 75 percent greater than 1,200 lb. Class "B" rock was 14 to 

 1,000 lb with 50 percent greater than 100 lb. Rock spall was 6 in. 

 minus . 



1985 The harbor is illustrated in Figure 5, and an aerial photograph of 



the harbor is presented in Figure 6. The breakwaters appear in good 

 condition at this time. 



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