IV-441 



beneficial effects, but radical changes in the annual river flow 

 pattern may cause drastic changes in both water circulation and in 

 ecological balance. 



The harbor of Charleston, South Carolina, was a deepwater port with 

 freshwater inflow from only coastal drainage until the flow of the 

 Santee River, averaging 15,000 cubic feet per second, was diverted 

 into it. This caused salinity stratification to set in and sedimenta- 

 tion became a severe problem. Dredging requirements grew from 120,000 

 cubic yards per year to over 7,000,000 cubic yards per year and many 

 of the docks had to be abandoned because adequate depths could not be 

 maintained. The prohibitive dredging costs have resulted in a Corps 

 of Engineers proposal to redivert the Santee River away from 

 Charleston Harbor, (see case study p. IV-484) 



Some of the more productive oystering areas in the Potomac River 

 are in a reach where high springtime river flows reduce salinities 

 enough to kill the oyster drills (a predator) but not kill the oysters. 

 Flow regulation to reduce the high spring flows would probably change 

 this relationship. 



RESTRICTIVE IMPACTS 



Some estuarine uses may restrict use for other purposes but do not 

 automatically exclude other uses. These are those activities which 

 do not require a permanent modification of the estuarine system; they 

 generally include those uses directly involved with the estuarine waters 



