Rainfall Deficits in Augusta Area
October is typically the driest month of the year. This year was no exception. October marks the second month in a row we’ve experienced below-average precipitation. Hartwell received 1.6 inches for the month coming in 2.5 inches below average. Thurmond received .59 inches of rain coming in 2.41 inches below average.
The recent deficit follows an exceptional volume of rainfall over the summer which took the basin into flood risk management status. Despite the September and October shortfall both Hartwell and Thurmond remain near guide curve. We continue to monitor the condition of the basin and project reservoir levels will remain near guide curve into January.
Thoughts from the commander on the recent deficit:
Today, Thurmond is at guide curve and Hartwell remains slightly above guide curve. As many of you have observed, streamflows have been decreasing which is typical this time of year. Due to this decline, we have had several requests to reconsider our position on the winter drawdown of both Hartwell and Thurmond Lakes. It remains our position that long term drought projections and forecasts for winter precipitation currently do not warrant a departure from our Drought Management Plan. Our drought plan, which was recently revised September 2012, is designed to handle dry periods should conditions worsen. Therefore, we intend to proceed with the winter drawdown associated with our Water Control Manual.
If you’re not already aware, we started investigating whether a smaller (or larger) drawdown of the pools is necessary. In October, we started modeling to update the probable maximum flood for the reservoirs. This output, in turn, will be used to see whether our current level of flood storage is adequate, or whether more or less storage is needed. The results of this flood storage analysis will not immediately invoke change. However, it may be a catalyst for considering a reallocation of storage. The results could reveal that a four foot drawdown is not necessary. On the other hand, it may reveal that a lower summer pool may be warranted to fully accommodate the amount of flood storage needed.
I hope this helps provide more clarity on how we are addressing the deficits in the last several weeks.
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