The rain event that occurred Sunday, April 19, caused both Hartwell and Thurmond to exceed the limits of conservation storage (almost simultaneously) as water levels rose into flood storage territory. As of this writing, Hartwell’s elevation has climbed more than six inches above the conservation threshold (660.51 feet above mean sea level) and Thurmond follows close behind.
Although it was a moderate rain event, the ground was already saturated from a slow but steady drizzle of (almost) daily precipitation for the past two weeks. The saturated conditions resulted in fairly high rainfall-to-runoff ratio, making the reservoir levels more responsive to rain.
The timing of the rain event was noteworthy considering the last time both Hartwell and Thurmond recorded levels in the flood storage range was April 19, 2014 – exactly one year ago from Sunday’s showers.
We plan to slowly evacuate the flood-storage water over the next few weeks to accommodate fish spawning, which should end in early May. If we get more rain within the next week or so, we may need to increase releases a bit to prevent using any more flood storage reserve.
~Russell Wicke, Chief of Corporate Communication COE