IV-368 



The detrimental effects of sedimentation are reflected in an impair- 

 ment of uses such as navigation, recreation, water supply, and fish 

 propagation. Navigational interests are damaged by the accretion of 

 materials in ship channels and near docking facilities; millions of 

 dollars are expended each year in channel dredging to maintain 

 navigation. Recreational interests suffer from the loss of safe 

 boating water, increased maintenance of marinas, and from the loss 

 of fishing areas (Figure IV. 5. 8). The cost of diversion and use for 

 water supply purposes may be significantly increased because of the 

 need to remove excess sediment. 



Fishery loss stems from the destruction of suitable habitat. This 

 damage results from loss of suitable breeding areas, loss of food 

 chain organisms because of change in benthic characteristics, and 

 fish kills from excessive turbidity. 



Channel maintenance adds to the sedimentation problem. The cost of 

 dredging is greatly influenced by the selection of spoil areas; if 

 the spoil is redeposited in the water environment, changes in bottom 

 characteristics are transferred to other areas, thus expanding the 

 scope of impact. Dredging spoil disposal results in increased 

 turbidities as well as changing bottom configuration. Both occurrences 

 can adversely affect the aquatic habitat. Natural sedimentation is an 

 integral part of the estuarine environment. Man-made sedimentation 

 problem is a form of pollution that is significant in terms of dollar 

 damages and must be considered in the overall management scheme. 



