Saturday, January 4, 2014

WE JUST COMPLETED MAJOR TEST OF RULE CURVE

The massive rains occurring with Lakes Thurmond and Hartwell down 2' should make it possible to decide on future drawdowns during the winter.  The perspective will vary depending on whether you are a lake stakeholder or environmentalist or stake holder along the lower Savannah River.  At present there are no lake stakeholders involved in the meetings where decisions of this nature are made. Hence decisions are not balanced with respect to lake stakeholder needs. So the purpose of this blog will be to present things from the perspective of the Lake Stakeholder.

In the past the Corps has used a 4' draw down in the winter.  This is not a problem if you come out of the winter with good Spring rainfalls.  However based on the past decade this has been a major problem. Starting out a dry season with the lakes already down 4' has led to severe damage to the recreation infrastructure of both Thurmond and Hartwell.  Two changes are needed if we are to avoid such disasters in the future.  First the draw down needs to be 2' rather than 4' and second the Corps needs to immediately reduce flows anytime lake levels begin to drop. 

From the standpoint of Recreational Infrastructure, a drop of up to 8' in a major drought is acceptable.  But drops in excess of 8' are very destructive.  Keeping the lakes within 2' of full pool during the winter and reducing release rates to maintain level as soon as the lakes start to drop would prevent dropping more than 8' even in the worst drought experienced in the last decade. 

Following is a quick review of how this approach affects the different stakeholders:
  • Environmental concerns can be met as long as you do not drop the release rate below 3600cfs.  Holding release rates higher than this simply extends the time the river is in drought condition coming out of the drought which has caused extended problems from an environmental standpoint in the major droughts of the past decade. 
  • River stakeholder concerns involve excessive flows under flood conditions and too little flow when recovering from a drought.  The proposal for 2' draw down during the winter should simply swing the balance toward higher flows and less time in a drought whenever we are in a major drought.  Water quality and water supply should be acceptable as long as release rates remain at or above 3,600cfs from Thurmond.
I am not listing how these affect lake stakeholders to emphasize the fact that they are not represented at the meetings where these matters are discussed and decisions on release rates are made.  Until we get representation from someone with a substantial stake in recreation at the Corps meetings where these decisions are made we cannot expect the decisions to be balanced.

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