IV-376 



generate employment opportunity. This complex, called the Santee- 

 Cooper Project, involved the diversion of the Santee River into the 

 Copper River through Lake Marion and Lake Moultrie. The outflow from 

 Lake Moultrie would go through a hydroelectric plant into the Cooper 

 River. In addition to the creation of large recreation lakes the 

 project would open a navigation channel to Columbia, S. C. It was 

 felt the increased flow in the Cooper River would benefit Charleston 

 Harbor, because it would help flush pollutants from the harbor and 

 improve water quality (Figure IV. 5. 13). 



The project was completed and placed in operation in 1942. By 1947, 

 shoaling rates in the Harbor had increased to the point where dredging 

 was a full time operation. Hydraulic model studies found the answer 

 to the increased channel maintenance; the higher fresh water inflow had 

 markedly increased salinity stratification and resulted in the forma- 

 tion of a salt wedge. Particles were entrapped in the wedge, and 

 deposition of sediments increased. 



The intended modification changed the circulation patterns and instead 

 of improving conditions in the Harbor, created more serious problems. 

 There is now a recommendation to divert the flow back into the Santee. 

 The net long run effect, regardless of the outcome of this recommenda- 

 tion, will be the complete alteration of two estuarine systems with 

 an unknown total effect on the ecosystem (IV-5-4). 



