Table 29 (Concluded) 



Date(s) 

 1981 



1983- 

 1985 



Construction and Rehabilitation History 



1985 



The 2,000-ft extension to the north Jetty and the 2,500-ft extension 

 to the south Jetty were approved. The north Jetty extension included 

 the 600-ft extension authorized in 1958. 



The Jetties were extended. A 756-ft length of the north Jetty was 

 rehabilitated, and the Jetty was extended 2,500 ft. The south Jetty 

 was extended about 2,300 ft. Four spur "wings", each 100 ft long, 

 were constructed at a 45-deg angle near the end of each Jetty. The 

 project required 1,300,000 tons of rock. Crest elevations of the ex- 

 tensions were +18 ft rallw, except for the seaward 300 ft of the north 

 Jetty and the seaward 500 ft of the south Jetty, which had crest ele- 

 vations of +20 ft mllw. Crest elevation of the spurs varied from 

 +18 ft to +14 ft mllw. The top width of the extensions was 34 ft, 

 and the side slopes were 1:2 above rallw and 1:1.5 below mllw. Armor 

 layer thickness was typically 14 ft on the extensions, using class 

 "A" stone weighing between 11.5 and 18.9 tons and averaging 15 tons. 

 Select class "A" stone weighing a minimum of 19 tons was used for the 

 armor layer near the end of each extension. Stone weights were based 

 on a unit weight of 165 pcf. 



The harbor and cross sections of the jetties are illustrated in 

 Figure 61. Both jetties are in good condition at this time. 



Figure 60. Aerial photograph of Jetties at Siuslaw River, Oregon, 1969 



131 



