Table 26 



Nehalem River 



Oregon 



Date(s) Construction and Rehabilitation History 



1890 The initial project was authorized. 



1898 The initial project was terminated before construction had begun. 



1910 Local interests began construction of the south Jetty. 



1912 The existing project was authorized, including two high-tide rubble- 

 mound breakwaters 700 ft apart at the outer ends. 



1915 Construction of the south Jetty was completed. The Jetty was 



4,500 ft long, including the work begun by the local interests in 

 1910. Crest elevation was +10 ft mllw with a 10-ft crest width and 

 1:1 side slopes for the first 3,000 ft, and crest elevation was 

 +12 ft mllw with a 15-ft crest width and 1:1.5 side slopes for the 

 outer 1,500 ft. 



1918 Construction of the north jetty was completed. The Jetty was 

 3,300 ft long. The crest elevation was +10 ft mllw with a crest 

 width of 15 ft for the first 1,600 ft, and crest elevation was +12 ft 

 mllw with crest width of 20 ft for the seaward half of the Jetty, all 

 with side slopes of 1:1.5. 



1919 Jetty subsidence and storm-related damage had lowered the outer 

 200 ft of both Jetties below low water. 



1934 The project was classified inactive. The seaward 200 ft of the north 

 Jetty was below mllw, and the rest of the structure was between +3 

 and +5 ft mllw, with the highest elevation at +9 ft mllw. The outer 

 220 ft of the south Jetty was below mllw, with the remaining length 

 predominantly below mllw. 



1979 The outer 200 ft of the north Jetty was below mllw, the majority of 

 the structure was below +6 ft mllw, and the maximum elevation was 

 +7 ft mllw. Approximately 700 ft of the north Jetty shoreward of the 

 high waterline on the spit was covered with sand. The outer 400 ft 

 of the south Jetty was below mllw, the next 1,400 ft was at about 

 +3 ft mllw, and the remainder of the structure was at about +5 ft 

 mllw, with a maximum elevation of +7 ft mllw. 



1981 Major rehabilitation of 3,500 ft of the north Jetty and 4,400 ft of 

 the south Jetty was undertaken. The Jetties were rebuilt to a crest 

 elevation of +16 ft mllw, crest width of 26 ft, and side slopes of 

 1:1.5. Estimated stone required for the north jetty included 

 63,600 tons of class "A", 40,100 tons of class "B", 12,800 tons of 

 core stone, and 9,500 tons of bedding stone. The south Jetty 



(Continued) 



124 



