Table 29 



Siuslaw River 



Florence, Oregon 



Date(3) Construction and Rehabilitation History 



1890 The original project was authorized. 



1891 The original project was modified. The project included a 10-ft 

 channel maintained by two high-tide rubble-mound Jetties that were 

 600 ft apart at the ends. The north Jetty was 7,500 ft long; the 

 south Jetty was 5,600 ft long. 



1893 Construction began on the north Jetty. 



1905 The project was suspended. The north jetty had been constructed to 

 4,090 ft, and work had not been started on the south Jetty. 



1910 The existing project was adopted. The project included an 8-ft-deep 

 bar channel maintained by two high-tide rubble-mound Jetties that 

 were 750 ft apart at the ends. The north Jetty would be extended by 

 3,700 ft, and the south Jetty would be 4,200 ft long. 



1912 Work on the jetties was suspended. 



1916- The south Jetty was repaired and extended. 

 1917 



1917 The Jetties were completed. The north jetty was 7,490 ft long and 

 included 441,237 tons of stone. The south jetty was 3,945 ft long 

 and used 196,860 tons of stone. Both jetties had crest elevations of 

 +15 ft mllw, crest widths of 15 to 20 ft, and side slopes of 1:1.5 to 

 1:2. 



T955 The south jetty had been deteriorating since 1917. Deterioration 



accelerated in 1955 when a portion of the jetty near shore that had 

 been constructed in 1912 was exposed. 



1957 The north Jetty was repaired. Class "A" armor stone used were over 



6 tons each and averaged 10 tons. Class "B" stone was over 1 ton and 

 averaged 3 tons. 



1958 The 600-ft extension to the north Jetty was approved but deferred. 



1961 The outer 300 ft of the south Jetty was at mllw. The crest of the 

 rest of the jetty varied from +5 to +10 ft mllw. 



1969 An aerial photograph of the jetties taken in 1969 is presented in 

 Figure 60. 



(Continued) 

 130 



