IV-427 



Water quality changes resulting from the construction of flow 

 regulation structures are demonstrated in the following examples: 



(1) In the San Francisco Delta, upstream 

 salinity intrusion is controlled by releases from 

 reservoirs on the Sacramento River. Conversely, 

 regulation of flow in the San Joaquin River is 

 partially responsible for recurring quality problems 

 in the Stockton area of the Delta; and 



(2) The construction of Santee-Cooper complex 

 in South Carolina resulted in the diversion of 

 the combined flows of the Santee and Cooper Rivers 

 into Charleston Harbor. This flow regulation created 

 a complex sedimentation problem and changed the 

 vertical salinity in Charleston Harbor. 



Upstream Water Quality 



Among the more significant considerations in the quality of any 

 estuarine environment is the quality of the inflowing stream. 

 If the freshwater inflow is polluted, the impact may be felt 

 throughout the entire system. A good example of this phenomena 

 is the St. Johns River in Florida. The St. Johns carries large 

 quantities of municipal and industrial wastes into the tidal area 

 (IV-5-10). 



The poor quality is further degraded by additional waste dis- 

 charges from the urbanized area near the estuary mouth. The total 



