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

Center Hill

Water quality conditions in Center Hill Lake followed the usual pattern for a reservoir serving as a storage project. Gradual declines in DO occurred in the water column below the upper layer of the lake (epilimnion). The deeper, colder zone (the hypolimnion) saw gradual but not total depletion of DO. Biweekly monitoring of conditions in the area just upstream of the dam (forebay) and tailwater revealed DO reaching action levels (<6.00 mg/l) by mid-September. (An action level is a boundary set as a water quality standard. By law, dissolved oxygen (DO) should not be lower than 6 milligrams per liter.) One more set of readings was collected to confirm and then the Corps began operating a sluice to mix with water released from the turbine in order to raise oxygen levels. This mixing or blending arrangement, though not a perfect solution, does result in a tailwater that is fairly well blended with oxygen all across the river channel and continuing a couple of miles downstream from the dam. The blending of turbine and sluice continued until December 14, when measurements of DO indicated a return of acceptable conditions in the turbine release. Lake elevations declined throughout the summer as Center Hill supplied water to the Cumberland River to slow the drop at Dale Hollow and maintain key downstream facilities. As with Wolf Creek, fall finally brought a series of rain producing systems that helped stabilize the pool, even though it was still fairly low.

Corps Water Management personnel taking water quality readings in the Center Hill Dam tailwater.

Center Hill Dam will undergo major repairs beginning in 2008. These will continue for several years as the Corps attempts to reduce seepage and leaks in the natural terrain surrounding the dam and in the embankment. Pool levels will likely be lower in 2008 as the Corps will be under a more restrictive fill regime to enhance public safety for those living downstream of this structure. Water management options resulting from a lower pool are likely to be more challenging both at Center Hill and for the overall Cumberland River Basin.