Maintenance dredging of the Mobile Ship Channel (Mobile and Biloxi quad- 

 rangles) between 1968 and 1973 produced 11,469,000 m 3 net (15,000,000 yds 3 

 net) of spoil (Alabama Coastal Area Board 1979). The average annual net 

 volumes of dredged maintenance material produced from the Mobile Harbor 

 system between 1967 and 1975 are shown in Table 17. 



Almost all of this dredged material is dumped in disposal areas 

 designated by the U.S. Army Corps of Engineers approximately 548 m (600 yd) 

 on either side of most of the channels in the area. Onshore dredge spoil 

 disposal areas include sites at Theodore (Mobile quadrangle), Bayou La Batre 

 (Biloxi quadrangle), and Blakely Island (Mobile quadrangle). On Blakely 

 Island, the U.S. Army Corps of Engineers covers mineral residue ponds with 

 dredge spoil , which provides both needed area for spoil disposal and covering 

 for potentially harmful chemical waste (J. Baxter, U.S. Army Corps of 

 Engineers, Mobile, 15 December 1982; pers. comm.). 



OFFSHORE OBSTRUCTIONS AND STRUCTURES 



The only major offshore structures in Mobile and Baldwin Counties are the 

 Mobile Bay Light, the Sand Island Light and three petroleum platforms 

 associated with the Lower Mobile Bay Field (Biloxi quadrangle). The Middle 

 Bay Light was constructed in 1884 and is located, as the name implies, in the 

 middle of Mobile Bay on the navigation channel. This structure is discussed 

 further in the atlas section dealing with the National Register of Historic 

 Places. 



The Sand Island Lighthouse is located near Sand Island about 5 km (3 mi) 

 south of the mouth of Mobile Bay. It dates to 1873 and was abandoned in 

 1971. Like the Middle Bay Light, it is on the National Register of Historic 

 Places and is discussed further in that section. 



Table 17. Average annual volume of maintenance bottom 

 materials dredged from the Mobile Harbor system, 1967-75 

 (U.S. Army Corps of Engineers 1980). 



Amount 

 3 

 Channel (yd /yr) 



Mobile River (including 



Chickasaw Creek) 1,054,000 



Mobile Bay 3,743,000 



Mobile Bar Channel 264,000 



Total 5,061,000 



69 



