Table 11 



Saco River Jetties 



Mouth of the Saco River, Maine 



Date(s) Construction and Rehabilitation History 



1873- During this period (noninclusive) the north (Sharp's Ledge) and 

 1912 south (Hills Beach) jetties were constructed to lengths of 4,100 and 

 4,800 ft, respectively. The north jetty had an elevation of +15 ft 

 mlw and an 8-ft crown width. The south jetty top elevation and width 

 were +5.5 ft mlw and 10 ft, respectively. Jetty side slopes were 

 1V:1H. The jetties are roughly parallel and spaced 700 ft apart 

 (Figure 12, present plan view). The south jetty extended approxi- 

 mately 1,600 ft bayward of the north jetty. The mean tide range is 

 8.8 ft. 



1927- The north jetty was extended 1,600 ft bayward. The design cross sec- 

 1930 tion was identical to that used on the south jetty. The extension 



resulted in adjacent bayward ends of the jetties. Repairs were made 

 on the outer 1,600 ft of the south jetty. The repair cross section 

 was identical to the original design. Extension and repair costs 

 totaled $53,800 with approximately 18,100 and 2,450 tons of stone 

 placed on the north and south jetties, respectively. 



1934- The north jetty was extended 900 ft bayward, and at the landward end 

 1938 a 160-ft section was repaired. The extension gave the jetty a total 

 length of 6,600 ft, and the design cross section was similar to that 

 of the previous extension. The design cross section for the landward 

 repairs specified a +18 ft mlw elevation, a 12-ft crown width, and 

 1V:1H side slopes. 



1958 The landward 700 ft of the north jetty were repaired to a crown 



elevation of +15 ft mlw, a 12-ft crown width, and slopes of 1V:1H and 

 1V:1.7H on the channel and bay sides, respectively. Stone size 

 varied from 0.5 to 7 tons or more, with 75 percent of the stone 

 averaging more than 5 tons apiece. Prior to the repairs, existing 

 center-line elevations varied from +9 to +15 ft mlw. A total of 

 5,100 tons of stone was placed for a cost of $38,000. 



1969 Repairs were made at the landward ends of the jetties by placing a 

 seal blanket of 1- to 150-lb stone and 0.5- to 1.0-ton cover stone. 

 Repair sections were 1,000 and 1,100 ft in length on the north and 

 south jetties, respectively. The repair geometry was placed on the 

 bayside slope of the existing jetty sections, with a minimum 

 blanket thickness of 3 ft and a 2-ft cover layer. The north jetty 

 design geometry had a +17 ft mlw crown elevation, various crown 

 widths from 3 to 12 ft, a variable bayside slope matching the exist- 

 ing slope, and a 1V:1H channel side slope. The south jetty design 

 geometry consisted of a +11 ft mlw crown elevation, 3-ft crown width, 

 and 1V:1.5H side slopes. The cost for placing 16,600 tons of stone 

 was $199,000. 



(Continued) 



24 



