In Dec. 13 IssueRussell County News
Thanks to the dry autumn and continuing repair work on two major dams, water flow in the Cumberland River system has become a tricky business according to the U.S. Army Corps of Engineers as they try to keep the river with enough level for commerce and enough water for cities and communities that depend on it resource for water supplies and fire protection.
The Corps has announced that – barring some significant rainfall runoff into the river basin and its lakes by the end of the year – they could be facing “some very difficult decisions regarding river and lake levels.”
Extremely dry weather conditions coupled with lake level draw downs associated with ongoing repair work at Wolf Creek Dam and Center Hill Dam has cause low levels in associated reservoirs as well, as water managers try to balance the needs of the river and downstream communities by carefully releasing amounts from them.
With Lake Cumberland held at an already low level to reduce stress on Wolf Creek Dam, and Center Hill Lake in the same predicament with virtually the same problems; water from Dale Hollow Lake has been used to help balance the river flow.
However, as a result Dale Hallow’s level has fallen slowly for many months and is now nearly 3/4th of a foot lower than it was in December 2007. It is currently the lowest it has been since November 1983 when it reached elevation 632.8 feet above mean sea level.
The record low level for Dale Hollow of 631.1 was observed in January 1956. Current projections, if there is no significant rainfall, call for Dale Hollow to continue to fall slowly to around elevation 633 by the end of the year.
Corps of Engineers water managers are operating the Cumberland River Basin reservoir system (all the reservoirs on the streams and tributaries of the river) in accordance with the interim operating plan developed prior to the onset of construction work at Wolf Creek Dam. At the same time, the lake level restrictions set for Wolf Creek Dam and Center Hill Dam have severely reduced the volume of water available to manage.
Bob Sneed, who oversees water management activities for the Cumberland River Basin projects explains, “We started out the summer season with only about one-fourth the normal volume of water in the reservoir system. This limitation is far more extreme than any drought that we have experienced since the reservoir system was completed.”
The Cumberland reservoir system is designed to store a large volume of cold water in the late winter and spring and then release that water from storage during the summer and fall when natural stream flows will not meet the water demands placed on the system.
According to Sneed, “In 2007 and 2008 we have operated the system according to the priorities established in the interim operating plan.” The system priorities detailed in the plan are 1) water supply, 2) water quality, 3) navigation, 4) hydropower, and 5) recreation – in that order.
The reservoir system continues to be available for flood damage reduction operations as needed.
According to a news release, Corps of Engineers water managers continue to work closely with representatives from federal, state, and local agencies, and various water users to reduce or eliminate the impacts from this limited supply of water in order to conserve and stretch resources.
The basic approach has been to route the minimum volume of water through the reservoir system needed to maintain an uninterrupted water supply to water intakes, avoid serious environmental consequences, and keep commercial navigation traffic moving.
Hydropower production and certain forms of recreation have been the uses most impacted by this operational plan. Very little to none has been supplied by the generators at Wolf Creek and Center Hill as a result of their very low levels and minimal releases.
Downstream of the Lake Cumberland, Dale Hollow and Center Hill lakes region, water flowing through the main-stem navigation lakes and dams along the Cumberland River – Cordell Hull, Old Hickory, Cheatham, and Barkley – will continue to be very low, but those lake levels are not expected to fall to critical levels.
The Tennessean newspaper of Nashville noted the low levels in Lake Cumberland and Center Hill reduces the amount of water the Corps has available to send further downstream in spring as needs arise.
“Water of a certain depth is required all along the system, so boats can navigate and reach docks, communities can access water through intake pipes, and fish and mussels can survive,” the Tennessean reported, adding: “Water rationing has occurred and expanses of mudflats with docks high and dry have been seen on several lakes in the past two years as drought has parched parts of the state.”
Lake visitors are being asked to use caution and be aware there may be unmarked structures underwater that could damage vessels. Visitors should also be mindful of wakes, tie-ups and prop washout when launching or near the bank. These courtesies will help ensure that current conditions do not add to the problem of shoreline erosion.
At each of the affected lakes, boaters planning to use ramps located within marina areas are encouraged to contact that marina to obtain the status of individual ramps. Corps of Engineers ramps located elsewhere around the lakes may be used at the boater’s discretion, but during this period of low water, it is best to always check the condition of the ramp prior to launching.