requirements. Locations should be encouraged where it is feasible to 

 build pile-supported piers out to reach suitably deep water. To 

 eliminate dredging, shal low draft boats may use the landward end of the 

 pier, and the larger boats the deeper-water end. 



Properly located piers avoid vital areas such as wetlands, grass 

 beds, shellfish beds, and endangered species habitats. The Corps of 

 Engineers limits the encroachment of piers into coastal waters and 

 wetlands to prevent interference with navigation or vital areas. For 

 example, the Baltimore District Office of the Corps has generally not 

 approved piers that extend within 15 feet of navigation channels and 

 has limited the length of all piers to less than one-third of the 

 width of the watercourse [45]. State and local jurisdictions often 

 require or recommend similar or more restrictive limits. 



4.2.3 Design 



Solid-fill structures extending into water areas are discouraged in 

 most states, except where winter ice conditions preclude piling-supported 

 structures. Filling and bulkheading that normally accompanies solid-fill 

 piers encroach onto the natural shoreline and are generally considered 

 to have adverse effects on coastal ecosystems. Solid-fill piers displace 

 aquatic habitat, alter water flows, create eddies and turbulent back- 

 waters, and increase localized sedimentation. The use of floating docks 

 or pile-supported piers is strongly encouraged by many agencies [46][47][48] 

 Pile-supported piers placed over a wetland area should be sufficiently 

 elevated to allow sunlight entering from the sides to sustain the aquatic 

 ecosystem underneath. 



4.2.4 Construction 



In constructing a pier, care should be taken to prevent pollution of 

 coastal waters by silt and associated contaminants. For example, driving 

 piles is preferred over hydraulic jetting because jetting tends to force 

 silt into the water, which may adversely affect water clarity, reduce 

 dissolved oxygen, and smother bottom organisms. Jetting is especially 

 discouraged in wetlands and nearshore waters where the fineness and the 

 organic content of sediment may be the greatest and where the material is 

 most suspendible and most highly polluting. 



Appropriate scheduling of pier construction activities may reduce 

 interference to aquatic organisms during important life phases, particular- 

 ly migration, spawning, and larval growth stages. 



4.2.5 Accumulated and Indirect Effects 



A dense accumulation of individual piers can cause a major obstruction 

 of water flow along the shoreline, as well as significantly litter and 

 pollute the water (e.g., leaks or spills of oil and gasoline) or restrict 



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