Water Management Situation Report for Cumberland River Basin Reservoir System and Associated Waterways

Dale Hollow

Dale Hollow Lake remains a key factor for the management of flows in the Cumberland River. After providing a much needed flow boost to the Cumberland River during the early summer, reliance on water from Dale Hollow was gradually reduced by September, partially because managers had no way of knowing when or how much rain and runoff might come to recharge the lake. Other considerations included the gradual lessening of critical water needs downstream to keep TVA’s Gallatin and Cumberland City generating plants operating. A final factor was the fact that Dale Hollow is difficult to fill with over winter rains and snow. Dale Hollow is still at a fairly low pool level (635.8). Plans call for the Corps to try and fill Dale Hollow above the normal top of the power pool of 651.0. Encouragingly recent rains have stopped the decline in the pool level and actually small rises have been noted.

A scenic view of the Obey River below Dale Hollow Dam in Clay County, Tennessee.

Water quality conditions in Dale Hollow remained fairly favorable, probably helped by the extreme drought which generally prevented oxygen demanding materials and warmer water from entering the lake. This slowed the normal loss of DO in the cold hypolimnetic (deep water) zone of the lake. As a result, although DO levels did gradually decline in the outflow, they were below the 6.0 mg/l (parts per million) State Water Quality Standard for only a fairly brief period in early October. It has not been necessary at Dale Hollow to resort to sluices to boost DO. As of mid- December Dale Hollow had mixed to a depth of approximately 65 feet while the tailwater DO was 7.3 mg/l.