Researchers working on the Savannah River Comprehensive Study reached another milestone recently when they completed modeling for the first four drought operation plan alternatives.
The multiagency study seeks to provide a better understanding for the impacts and risks associated with managing water resources in the basin, specifically during droughts when those resources, and thus the environment and economy, are most vulnerable.
For this segment – the second interim phase of the study – researchers are using several computer models to evaluate potential modifications to the current drought plan. They are applying data collected from the basin for the past 73 years to the models to observe the impacts of those changes, according to William Bailey, chief of planning division at U.S. Army Corps of Engineers Savannah District.
By running these “what if” scenarios through the models using real data, researchers obtained a comprehensive view for the ramifications throughout the basin if certain factors are altered.
For example, alternative 2 considers the effect of redefining the elevation and outflow for Drought Level 3 at Thurmond Dam. Currently, Drought Level 3 is defined as 14 feet below summer full pool with a minimum outflow of 3,800 cubic feet per second (3,100 cfs from Nov. – Jan.). Alternative 2 identifies the impact of changing Drought Level 3 to 8 feet below summer full pool with a minimum outflow of 3,600 cfs.
Scientists with the U.S. Army Corps of Engineers Savannah District ran historical hydrological data through a reservoir model based on this alternative. The results were then passed to the Georgia Environmental Protection Division, which ran the numbers through a river-based model. Finally, those results were given to South Carolina’s Department of Natural Resources, which input the numbers into a harbor-based model.
Bailey said the study also considered how each alternative would impact other aspects such as fish spawning in the lakes, hydropower generation, availability of boat ramps and beaches, chloride levels for the city of Savannah’s intakes, and dissolved oxygen levels in the Savannah Harbor, to name a few.
Now after completing modeling for the first four alternatives, the team has begun incorporating the most favorable aspects from these alternatives into two additional combination alternatives. Then they will run the historical data through models to identify the effects of operating under those alternate drought plan scenarios.
When modeling for the final two combination alternatives is complete, the team will write a draft report of its findings and submit it for public comment. Bailey said he expects the draft to be complete by summer 2017.
The draft report, combined with public comments, will be evaluated against the current drought plan to determine whether it would be more favorable to modify the plan or keep the existing drought plan as is.
~ Jeremy S. Buddemeier, Corporate Communications Office