borrow pit and place the spoil to form a long continuous levee. The 

 dragline proceeds along the marsh surface on that side of the levee 

 from which the fill is borrowed and parallel to the levee route. 

 The fill is placed in a continuous pile 10 to 13 m (30 to 40 ft) 

 wide with an approximate slope of 30°. Three to 4 m (about 10 ft) 

 usually remains as a berm, that distance between the foot of the 

 levee and the edge of the borrow pit. The dragline shapes the 

 material only approximately and then leaves it to drain and dry. A 

 board road is placed on the top of the levee after synthetic mate- 

 rial is laid to control water seepage. The dragline may exit by 

 traveling on board mats, or if the roadway is completed, may be 

 loaded on a large equipment-moving vehicle. 



2. Primary ecological alterations 



2.1 Creation of ruts or depressions in land surface - marsh buggy 

 tracks and/or tracks from other accessory equipment 



2.2 Loss of vegetation along road pathway due to excavation and 

 covering 



2.3 Creation of borrow ditch 2 to 5 m (6 to 15 ft) deep for 

 increased saltwater inundation 



2.4 Increases in concentrations of suspended sediments and dis- 

 solved nutrients 



2.5 Blockage of normal surface-water runoff pathways by levee 



2.6 Creation of a pathway parallel to levee for more rapid upland 

 drainage and standing water from marsh 



Attribute alterations 



Surveyors and their equipment trample and crush vegetation outside 

 the zone to be excavated, but the area involved is small. Further- 

 more, much of this trampled area may be covered by fill as construc- 

 tion proceeds. A more significant vegetation loss occurs during 

 excavation of a 5-m (15-ft) wide borrow ditch and burial of some 

 bordering marsh by fill. The width of the latter zone is 10 to 13 m 

 (30 to 40 ft). This direct loss results in an immediate decrease in 

 food and cover for the consumers in the area. For a single roadway 

 through a salt marsh, the total area affected is usually small in 

 comparison to the remaining productive vegetation; the impacts on 

 animals, nitrogen fixation, and detritus export are minor. However, 



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