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

Cumberland Tailwater - Fall 2009

The Kentucky Department of Fish and Wildlife Resources (KDFWR), working closely with the Corps of Engineers (Corps) through the summer and fall 2009 monitored water quality conditions in the Cumberland tailwater.  KDFWR personnel deployed temperature loggers at several locations in the tailwater to record hourly water temperatures.  Late summer through early fall was a difficult period for rainbow and brown trout in the Kentucky portion of the tailwater.  Although flows were adequate, water temperatures throughout the tailwater were much warmer than normal and oxygen levels near the dam were reduced.

The abundant rainfall during the year affected the temperature and oxygen levels in Lake Cumberland, which ended up affecting tailwater conditions as well.  As mentioned in the Lake Cumberland report,  the usual abundant supply of winter-stored water that supplies the tailwater with cold water throughout the summer and fall was flushed from the lake early in the year (due to heavy rains) and replaced with warmer water from spring and summer rains.  By summer, water temperatures in the mid and lower depths of the lake (which supply the tailwater), were much warmer and less oxygenated than normal. 

The Corps tried to maximize the available cold water during the summer and fall by adjusting the release patterns.  Turbine releases (at mid-depths) were utilized mostly at first, and later supplemented (or replaced) with the colder sluice gate releases (from the bottom of the lake) as needed.   By mid-summer, the colder, better oxygenated sluice water was desired over warmer turbine water.  Unfortunately, the persistent rains required the continued use of both the turbines and sluices during much of the summer and fall to flush excess water from the lake. 

Despite efforts to conserve cold water for trout, water temperatures in the tailwater near the dam reached 60 degrees by mid-June, then dropped into the mid 50’s for most of July (because of sluice releases), then hovered near 60 degrees through most of August and September.  October was the most critical period in the tailwater as water temperatures near the dam stayed near 65 degrees throughout the month, before finally cooling slightly in early November. 

Water temperatures downstream were even higher, due to the sun’s heating.  At Burkesville, located about midway to the state line, water temperatures rose above 60 degrees in late May and remained 60-68 degrees from July through October.  Although those temperatures aren’t lethal to trout, they were likely stressful and caused the trout to feed less often, contributing to their reduced body condition and slower growth. 

The warm waters particularly affected trout production at Wolf Creek National Fish Hatchery.  The hatchery began experiencing problems in late summer related to the warm, poorly oxygenated water flowing into the hatchery from the lake.  Conditions became critical in September, and trout stockings slated for the tailwater in October and November were released early (mid-September to early October) to ease pressure on the trout production at the hatchery.  KDFWR also shifted stockings toward the upper river during the summer and fall, where the waters were slightly cooler, to more effectively utilize the trout.

In response to the hatchery’s early release of additional fish into the tailwater, KDFWR enacted an emergency regulation on September 11 that increased the creel limit on rainbow trout from 5 to 10 fish.  The 15-20-inch protective slot limit on rainbow trout remained and still remains in effect.  One of the 10 rainbow trout in the daily limit may be 20 inches or longer.  The emergency regulation was designed to encourage anglers to harvest the additional “stocker” trout, while still preserving the larger fish in the population.  This prudent measure will likely remain in effect for the next few years until the dam repairs are completed and conditions in the tailwater return to normal.

Although the unusually warm temperatures in the tailwater negatively affected the trout fishery, other fish species benefited.  Preliminary creel survey results from KDFWR indicate that 25 species of fish were caught in the tailwater in 2009, compared to 11 species during the 2006 survey.  Normally, the cold water discourages fishes such as largemouth bass, channel catfish, and freshwater drum.  However, the unusually mild water temperatures apparently suited those species and they were much more prominent in the tailwater in 2009 than past years. 

On another positive note, anglers floating the river below Wolf Creek Dam will have a new public access site to stop and wade or fish from the bank.  The Kentucky Department of Fish and Wildlife Resources recently purchased a 20-acre island and adjacent 5-acre parcel of land in Clinton County.  The area is known as Long Bar or Snow Island and is about 10 miles downstream of Wolf Creek Dam, between Helm’s Landing and Winfrey’s Ferry boat ramps.  There is no road access to the area at this time but KDFWR plans to construct a road into the area and develop parking and bank access in the near future.  Once completed, the area will be opened to the public for parking and bank fishing.  The area was purchased with Sport Fish Restoration Funds that come from excise taxes on motorboat fuels and fishing equipment.

Cumberland Tailwater - Spring 2009

Water quality in the tailwater remained excellent throughout the winter and early spring. The cold water temperatures and higher oxygen levels were ideal for trout throughout the KY portion of the tailwater. Water quality should remain good through at least early summer.

The seasonal pulse of winter and spring rains increased water flows into the tailwater during the spring and limited wade fishing opportunities for anglers. The Corps increased generation this spring to move the lake level down toward the target elevation of 680 msl, so as the rainfall moves into summer patterns, flows should moderate and wading conditions should improve. The best-case scenario for the tailwater would be for moderate rainfall spread evenly throughout the summer. This would allow the Corps to maintain adequate tailwater flows to keep the water temperatures cold but still allow wade anglers easy access to the river.

The Kentucky Department of Fish and Wildlife Resources (KDFWR) is conducting a creel survey on the tailwater from April through November this year to monitor the fishery. The creel survey will be conducted 18 days per month in the Kentucky portion of the tailwater from Wolf Creek Dam to the Hwy 61 Bridge. During the survey, two creel clerks will conduct angler interviews and record catch and harvest data. The information gained during the survey will be used to better manage trout and other fisheries in the tailwater.

KDFWR will again work closely with the Corps through summer and fall 2009 to monitor water quality conditions in the Cumberland tailwater. KDFWR personnel plan to deploy temperature loggers at five locations in the tailwater (Winfrey's Ferry, Big Willis, Bakerton, Cumberland Co. Water Plant, and Cloyds Landing) during early summer to record hourly water temperatures. Conditions are looking tougher for the trout in the tailwater. The water currently coming through the dam is warmer than in previous years because of the earlier release of winter stored water and replacement with the warmer water from the April-May rains. At this point, agencies are planning to use turbine water as long as possible. When it becomes too warm, colder water released from sluice gates will be used. If temperatures become elevated this summer, KDFWR will consider enacting an emergency regulation for trout (no size limit, 10 fish creel) on a portion of the tailwater. If adequate rain falls, water supplies should remain healthy enough to release amounts of water to maintain good water quality in the tailwater and the emergency regulation will be unnecessary.

The Corps should have considerable flexibility in managing water flows into the tailwater in 2009 due to the restrictive devices on two sluice gates. The orifice gates restrict the water flow through each sluice to about 260 cfs. The reduced flow will allow the Corps to keep a sluice gate open continuously, which should improve water quality in the tailwater. This is particularly crucial during the summer, when continuous flows would help keep water temperatures cooler in the lower portion of the tailwater. However, KDFWR is considering discontinuing trout stockings in the lower portions of the tailwater this year.