It is factual that when you dredge a river on the coast, you cause two of many problems. 1-You increase the salt water intrusion that spills in to the fresh water aquifers, & 2-You change fresh water wetlands to brackish. It would appear logical that these problems would be resolved if you increase the flow of water from the fresh water river. This was a major concern of mine during the hearings of the Medical Affairs Committee and DHEC (Department of Health & Environmental Control) this week.
Here’s the problem. The Savannah River basin has three dams for Lakes Hartwell, Russell, & Thurmond. If the communities on the coast have these problems, why not let out more water from the dams upstream? The suffering lake levels may be reduced even further.
The answer below from the Corps of Engineers verifies this assumption, yet offers that the Corps will not consider this solution. I just hope this is a permanent determination.
You asked about the Corps’ consideration of additional releases from its reservoirs upstream on the Savannah River.
The Corps did consider releasing additional water from those reservoirs as a way of reducing or eliminating the salinity impacts from deepening the harbor. However, our analysis indicated that a large amount of water would be required to restore salinity levels to their present location in the estuary over a long period of time (such as in a multi-year drought). Substantial changes would have been required to the operation of those reservoirs, resulting in potentially large-scale adverse effects to existing users. As a result, the Corps dropped that measure from further consideration and it is not included as one of the final mitigation measures.
Chief, Planning Division