TVA September Reservoir System Update

Rain and runoff

The generally dry weather pattern that prevailed across the Eastern Valley much of the summer eased in August thanks in part to several days of soaking rain in the middle of the month. Eastern Valley rainfall for the year totaled 28.06 inches at the end of August, which is 7.7 inches below normal.

Runoff (the amount of water that reaches the river system when it rains instead of being absorbed into the ground) is currently 88 percent of normal in the eastern Valley.

Reservoir elevations

Wet weather in mid-August helped TVA maintain the higher flows needed in late summer for water quality and other river system benefits while keeping tributary reservoir elevations near normal. At month’s end, tributary reservoirs also were generally in balance—that is, the elevations of most reservoirs were about the same in relation to their balancing guides and flood guides. Watauga was the only exception. Although TVA conserved as much water in Watauga as possible throughout the summer, it was still somewhat low relative to other tributary reservoirs because inflows weren’t sufficient to compensate for the water released to meet downstream minimum flow requirements and recreation flow commitments.

TVA began a special deep drawdown on Blue Ridge Reservoir in mid-July. The reservoir is being lowered to an elevation between 1620 and 1630 feet above sea level as part of a project to rehabilitate the 79-year-old dam. Get an update on this project below.

Tributary Reservoir Elevations¹
Reservoir	Sept. 1, 2010 Observed Elevation	Jan. 1 Flood Guide Elevation2
South Holston	1721.7	Member Comments… Post a Comment