[Federal Register Volume 61, Number 100 (Wednesday, May 22, 1996)]
[Notices]
[Pages 25727-25729]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-12815]
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TENNESSEE VALLEY AUTHORITY
Chickamauga Dam--Navigation Lock Project
AGENCY: Tennessee Valley Authority.
ACTION: Issuance of record of decision.
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SUMMARY: This notice is provided in accordance with the Council on
Environmental Quality's regulations and with TVA's procedures
implementing the National Environmental Policy Act. TVA has decided to
adopt the preferred alternative identified in TVA's final environmental
impact statement (EIS) made available to the public on March 26, 1996.
A Notice of Availability of the final EIS was published in the Federal
Register on April 5, 1996 (61 FR 15252). The preferred alternative is
to construct a new 110 x 600 foot lock to replace the existing lock at
Chickamauga Dam. Because of structural problems and safety concerns
caused by concrete growth, the existing lock at Chickamauga Dam has a
limited life expectancy, at most 10 years. TVA will continue to monitor
the existing lock and make the necessary repairs to keep the lock in
operation until the new lock is available for service. Design and
construction of the new lock, subject to available funding, are
expected to begin five years prior to closure of the existing lock.
This will allow the new lock to be operational before the existing lock
is closed, thereby maintaining navigation on the upper Tennessee River.
FOR FURTHER INFORMATION CONTACT:
W. Gary Brock, Manager, Water Resources Projects and Planning,
Tennessee Valley Authority, West Tower 10C-432, Knoxville, Tennessee
37902, or by calling (423) 632-8877.
SUPPLEMENTARY INFORMATION: The Tennessee River is formed at the
confluence of the Holston and French Bread Rivers near Knoxville in
eastern Tennessee. From this confluence, the river flows 652 miles
through Tennessee, northern Alabama, northeastern Mississippi, and
western Kentucky to enter the Ohio River near Paducah, Kentucky. Along
most of its counsel, the river falls gradually for a total of 515 feet
except in the Muscle Shoals, Alabama, area where a drop of 100 feet
occurs in less than 20 miles.
The existing navigation system on the Tennessee River consists of
nine multipurpose dams and lock projects with a total of 13 navigation
locks. The system creates a series of navigation pools that provide a
nine foot navigable channel along the entire length of the river except
for a three mile stretch at Knoxville where, in periods of low water,
the depth diminishes to seven feet and the channel width diminishes to
about 200 feet. Navigation locks on the Tennessee River range in size
from 110 x 1000 foot lock at Pickwick Dam to 60 x 300 foot double lift
auxiliary lock at Wilson Dam.
The upper Tennessee River navigation system begins at Chickamauga
Dam, river mile 471, and extends 181 upstream to the confluence of the
Holston and French Broad Rivers. The system consists of four navigation
locks located at Chickamauga, Watts Bar, Fort Loudoun, and Melton Hill
dams. The four locks were constructed in 1937, 1941, 1942 and 1963
respectively. The predominant commodities trafficked on the upper
Tennessee River system are asphalt, grains, ores and minerals, and
forest products.
TVA's Chickamauga Dam and Navigation Lock Project is located in
Hamilton County, Tennessee, approximately 13 miles northeast of
downtown Chattanooga, Tennessee. Chickamauga Lock currently has a
traffic level of about 2.1 million tons per year.
TVA and the United States Army Corps of Engineers (USACE) began
studying navigation problems on the upper Tennessee River in 1987. The
study results were published in 1988 by the Nashville District of the
USACE in a report entitled, Commodity Traffic and Benefit Study for
Navigation Improvements on the Upper Tennessee River. Both agencies
agreed that the small and aging locks on the upper Tennessee River--
Chickamauga, Watts Bar, Fort Loudoun--were constraints to navigation
and that concrete growth at Chickamauga lock threatened its continued
operation. Concrete growth was not a problem at Watts Bar and Fort
Loudoun because of the type of cement and aggregate used to construct
the projects.
The 1988 study examined the feasibility of increasing the existing
locks to 110 x 600 feet size in order to bring the upper Tennessee
navigation locks into conformance with locks below Chickamauga on the
lower Tennessee River. The study concluded, however, that the benefits
would not justify the cost of three new locks on the upper Tennessee
River, and that TVA transportation planners should concentrate on
improvements at Chickamauga and Watts Bar Locks.
The results of the study of lock improvement benefits at
Chickamauga and Watts Bar Dams were presented in a USACE report
entitled Upper Tennessee River Navigation Improvement Study Navigation
System Analysis (1993) which was produced under contract for TVA. The
focus of this study was to estimate benefits that would accrue from a
new 110 x 600 foot lock at Chickamauga which would be constructed
before the existing lock was closed for an 18 month rehabilitation. At
that time, engineering data indicated that the lock could be
rehabilitated to function as an auxiliary lock. The study concluded
that if any capacity constraints occurred at Watts Bar Lock,
nonstructural measures could be used to
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control the situation. TVA will continue to evaluate Watts Bar and Fort
Loudoun projects. However, TVA has no planned upgrades of these
facilities in the foreseeable future.
Because of structural problems and safety concerns TVA continued to
perform engineering analyses of the Chickamauga Lock and Dam using new
methodology referred to as finite element analysis. The finite element
analysis completed in 1995, revealed that because of concrete growth
the lock could not be rehabilitated and that, at best, could function
for another ten years. At some point, the lock would have to be closed
to form a permanent water barrier at the dam. To close the lock, a
concrete plug would be poured into the lock chamber to form a permanent
water barrier.
Extensive structural repairs and maintenance activities to
alleviate problems resulting from concrete continue to be made at
Chickamauga Lock. Instrumentation was installed to monitor structural
movements and internal stresses.
In its evaluation of alternatives to replace the existing lock at
Chickamauga Dam, plugging the lock was defined as TVA's no action
alternative. At this time, the alternative of taking absolutely no
action is not acceptable because of the deteriorating nature of the
lock and potential consequences of dam safety and navigation.
TVA issued a draft EIS on May 10, 1995, that considered the
alternative of continued operation of the existing lock. The final EIS
does not consider the alternative of rehabilitating the lock because of
information described above that became available after release of the
draft EIS.
Alternatives Considered
The following four alternatives were considered by TVA in its final
EIS in attempting to address the structural problems and safety
concerns caused by concrete growth at the Chickamauga Lock.
Alternative 1. Construct a new 110 x 600 foot lock (preferred
alternative).
Alternative 2. Permanently close existing lock (no action
alternative).
Alternative 3. Construct new 60 x 360 foot lock (replacement in-
kind).
Alternative 4. Construct new 75 x 400 foot lock.
The environmental impacts of these alternatives were evaluated in
the final EIS. Because of the structural problems and safety concerns,
all construction alternatives include plugging the existing lock after
the new lock is completed.
Under the no action alternative, the existing lock would have been
plugged and no replacement lock built in its place. This would have
eliminated navigation through Chickamauga Dam. Upstream industries
dependent upon barge transportation would be forced to shift to truck
or rail transport of commodities, and recreational boaters and
commercial tour operator would not be able to move between Chickamauga
and Nickajack Reservoirs. Plugging the existing lock at a cost of $6.8
million to form a permanent water barrier at the dam would have been
the least cost alternative for solving the structural problems at the
lock.
The 110 x 600 foot lock represents the general standard for locks
on the lower Tennessee River and thus, is well suited for barges in
general use today. Lock capacity for the 110 x 600 foot lock has been
rated at 35.7 million tons. Construction of the 110 x 600 foot lock is
estimated to cost $225 million. Total cost of the new lock, including
$6.8 million for closure of the existing lock, is $231.8 million in
1995 dollars. Construction of the 60 x 360 and 75 x 400 foot locks
would have cost $135 million and $160 million respectively.
Basis for the Decision
TVA decided to adopt Alternative 1, that is, construct a new 110 x
600 foot lock, to address the structural problems at Chickamauga Lock
based on environmental, social, economic, recreational, and engineering
and public safety considerations. Alternative 1 was chosen as the
preferred alternative because it would maintain navigation on the upper
Tennessee River and represents the general standard for locks on the
lower Tennessee River and, thus is well suited for barges in general
use today.
Overall benefits include (1) economies related to a more efficient
lock at Chickamauga, (2) a cheaper competitive barge alternative to
overland transportation, and (3) construction of a reliable lock at
Chickamauga.
Among the three lock sizes considered in this EIS, the benefit cost
ratio (4.3) for the 110 x 600 foot lock is higher than the benefit cost
ratio (2.5) for the other two locks. The environmental impacts from the
construction and operation of the smaller 60 x 360 and 75 x 400 foot
locks would be similar to the impacts associated with the preferred 110
x 600 foot lock.
A new 110 x 600 foot lock is expected to generate 467 new jobs and
$16.7 million in new income annually in the Hamilton County area over
its five-year construction period. Of the 467 jobs, 267 would be
directly created while 200 mostly commercial sector positions would be
indirectly created. The $9.8 million directly generated income would
also result in an additional $6.87 million in indirect monetary gain.
While the bulk of these employment and income benefits would accrue to
Hamilton County, the project would also have a positive impact on seven
other counties identified in the project area.
Under alternative 2, plugging the lock would result in the
abandonment of 297 miles of navigable inland waterway and the public's
investment in three navigation locks (Watts Bar, Fort Loudoun, and
Melton Hill) above Chickamauga. The loss of commercial traffic on the
upper Tennessee River is estimated to cost the nation $25 million
annually. Additionally, having a lock in place at Chickamauga Dam
provides shippers in east Tennessee, North Carolina, Virginia, and
South Carolina a competitive alternative to overland transportation
modes and a low cost source of certain commodities. For these reasons,
the no action alternative is unacceptable to TVA.
TVA also considered the use of portage facilities around
Chickamauga Dam to support upstream barge use without the construction
of a new lock. However, because this alternative was not economically
feasible, it was not evaluated in detail.
Construction of a new lock would result in the loss of some
specimen of the endangered pink mucket during dredging for channel
improvements. Other potential adverse environmental impacts from
construction of a new lock can be substantially avoided or minimized
through mitigation measures. By comparison, the no action alternative
of plugging the lock without replacing it would stop navigation between
Chickamauaga and Nickajack reservoirs, isolate the upper from the lower
Tennessee River, and block the potential upstream movement of spawning
migratory species such as sauger and buffalo. TVA has therefore
concluded that there is no clear environmentally preferable alternative
for the Chickamauga Dam--Navigation Lock Project.
Environmental Consequences and Commitments
Environmental consequences associated with construction of a new
110 x 600 foot lock are set out in the final EIS. Environmental impacts
include minor loss of aquatic habitat and resident population of
freshwater mussels, included one listed
[[Page 25729]]
endangered species (pink mucket, Lampsillis orbiculata) These losses
would be mitigated by relocating the mussels and possibly by other
means to be determined during consultation with the United States Fish
and Wildlife Service. Disposal sites would be landscaped and vegetated,
and potential impacts to a federally endangered plant (Mountain
skullcap, Scutellaria montana) located adjacent to a disposal site will
be mitigated through maintenance of a contiguous 250-foot forest buffer
zone. Shoreline restoration downstream will be performed so as to
offset erosion and improve riverine wetlands downstream of the project.
Fugitive dust would be reasonably controlled through periodic wetting
of construction road surfaces or as required by local and state air
regulations. No chemical agents, such as oils, will be used to control
fugitive dust. Construction of a new lock will have an impact on the
existing historic dam complex and will require a Section 106 review. No
potential adverse effects on archaeological or cultural resources are
anticipated. Temporary high noise levels and navigation traffic
congestion would be expected during construction.
Environmental impacts associated with the operation of the new lock
include socioeconomic benefits associated with the continuation of
commercial and recreation lockages and the loss of four spillway bays.
Loss of four spillways bays will not adversely impact TVA's ability to
control flooding up to a 5500 year flood event. Further, through
appropriate design of discharge structures, TVA will attempt to
minimize potential impact on the upstream migration of certain fish
species, such as sauger and buffalo.
The construction and operational environmental impacts for the
smaller 60 x 360 and 75 x 400 foot locks would be similar to the
impacts associated with the proposed 110 x 600 foot lock.
Environmental impacts associated with the no action alternative of
plugging the lock without replacing it, include blocking the potential
upstream movement of spawning migratory fishes, such as sauger and
buffalo. Additionally, navigation through Chickamauga Dam would cease,
causing significant economic impact to industry and recreation and
would isolate the upper Tennessee River from the lower river system for
commercial navigation. This would result in a shift to land transport
of goods shipped through Chickamauga Lock which would have adverse
impact on air quality from increased truck and rail traffic. Further,
separation of the National Oak Ridge Laboratory and other industry from
access to barge transportation could result in lost opportunities for
industrial expansion, and at Oak Ridge, the inability to move certain
national defense equipment there for maintenance and repair.
Additionally, a number of mitigation and monitoring requirements
will be incorporated in construction and operational permits needed for
the Chickamauga Dam--Navigation Lock Project.
Dated: May 13, 1996.
Kathryn J. Jackson,
Senior Vice President, Resource Group.
[FR Doc. 96-12815 Filed 5-21-96; 8:45 am]
BILLING CODE 8120-01-M
