[House Document 105-173]
[From the U.S. Government Publishing Office]
105th Congress, 2d Session - - - - - - - - - - House Document 105-173
LOWER SAVANNAH RIVER, GEORGIA AND SOUTH CAROLINA ENVIRONMENTAL
RESTORATION PROJECT
__________
COMMUNICATION
from
THE ACTING ASSISTANT SECRETARY
(CIVIL WORKS),
THE DEPARTMENT OF THE ARMY
transmitting
A REPORT ON THE AUTHORIZATION OF AN ENVIRONMENTAL RESTORATION PROJECT
FOR THE LOWER SAVANNAH RIVER, GOERGIA AND SOUTH CAROLINA, PURSUANT TO
PUB. L. 104-303, SEC. 101(a)(11)
January 27, 1998.--Referred to the Committee on Transportation and
Infrastructure and ordered to be printed
C O N T E N T S
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Page
Letter of Transmittal............................................ xi
Comments of the Office of Management and Budget.................. xiii
Comments of the State of South Carolina.......................... xiv
Comments of the State of Georgia................................. xv
Comments of the Department of Agriculture........................ xix
Comments of the Environmental Protection Agency.................. xx
Comments of the Department of the Interior....................... xxi
Comments of the Department of Transportation..................... xxii
Report of the Chief of Engineers, Department of the Army......... 1
Report of the District Engineer:
Executive Summary................................................ 6
Introduction................................................. 6
Problem Needs................................................ 6
Environmental Restoration Alternatives....................... 8
Evaluation and Screening of Alternatives..................... 9
Section 1--Introduction.......................................... 19
Study Purpose and Scope...................................... 19
Study Objectives......................................... 19
Scope of Study........................................... 20
Study Authority.............................................. 20
Study Area................................................... 21
Federal Navigation Project................................... 25
Study Process................................................ 25
Lower Savannah River Basin Reconnaissance Report......... 27
Feasibility Study Cost Sharing Agreement................. 29
Prior Studies and Reports.................................... 29
U.S. Army Corps of Engineers............................. 29
Design Memorandum Savannah River Below Augusta
General Design..................................... 29
Environmental Resource Inventory of the Savannah
River Basin........................................ 29
Final Environmental Statement, Operation and
Maintenance of Navigation Project, Savannah River
Below Augusta, Including the New Savannah Bluff
Lock and Dam....................................... 29
Savannah River Below Augusta, Georgia, Evaluation of
Authorized Project................................. 29
Lower Savannah River Environmental Reconnaissance Report. 30
Other Pertinent Studies...................................... 30
Biological Surveys on the Savannah River in the Vicinity
of the Savannah River Plant (1951-1976)................ 30
U.S. Fish and Wildlife Service Planning Aid Report....... 30
Study Participants and Coordination.......................... 30
Report Contents.............................................. 32
Section 2--Baseline Conditions................................... 33
Basin Description............................................ 33
Land Use..................................................... 33
Historical Land Use...................................... 33
Historical River Traffic................................. 33
Current Land Use......................................... 36
Population............................................... 37
Geology and Soils............................................ 38
Geology.................................................. 38
Soils.................................................... 38
Physiography................................................. 39
Climate...................................................... 40
Basin Hydrology.............................................. 40
Water Supply and Water Quality............................... 42
Water Supply............................................. 42
Water Quality............................................ 42
Recreation................................................... 43
Cultural Resources........................................... 43
Savannah National Wildlife Refuge............................ 44
Description.............................................. 44
Refuge Boundary.......................................... 44
Ecosystem Within Study Area.............................. 44
Priorities for Environmental Restoration................. 47
Future Navigation on the Savannah River...................... 47
Section 3--Problem Identification................................ 51
Future Conditions Without Environmental Restoration.......... 51
Problems, Needs, and Opportunities........................... 52
Navigation Cuts.......................................... 52
Bends.................................................... 52
Wetlands................................................. 54
Riverine Fish Populations................................ 54
Savannah National Wildlife Refuge........................ 55
Significance and Scarcity of Resources................... 55
Non-Federal Concerns......................................... 57
Goals and Objectives......................................... 59
Federal Planning Objectives.............................. 59
Study Objectives......................................... 59
Public Concerns.............................................. 60
Section 4--Formulation of Environmental Restoration Measures..... 61
Study Objectives............................................. 61
Delineation of Study Area................................ 61
Environmental Restoration................................ 61
Environmental Restoration Benefits....................... 62
Formulation Issues........................................... 62
Separable Study Sites.................................... 62
Naximum Environmental Restoration........................ 62
Preliminary Restoration Measures......................... 63
Navigation............................................... 63
Environmental Restoration Benefits....................... 64
Net Environmental Benefits............................... 64
Constraints.................................................. 64
Components of Environmental Restoration Alternatives No
Action..................................................... 65
Conditions Prior to Navigation Cuts...................... 67
Current Conditions....................................... 67
Future Conditions........................................ 68
Cut and Bend #4 Restoration.................................. 68
Mill Creek Restoration....................................... 68
Cut and Bend #3 Restoration.................................. 68
Restoration of Bend #3................................... 68
Full Closure of Navigation Cut #3........................ 70
Full Closure Cut #3, Navigation Channel in Bend #3....... 70
Full Closure Cut #3, Restoration Channel in Bend #3...... 70
Partial Closure of Navigation Cut #3..................... 71
Partial Closure of Cut #3, Restoration Channel in Bend #3 71
Partial Closure of Cut #3, Slackwater Channel in Bend #3. 71
Bend #3, Modifications to Bear Creek..................... 71
Increase Flow to Existing Mouth of Bear Creek............ 71
Relocate Mouth of Bear Creek............................. 72
Potential Restoration Components Eliminated.................. 72
Summary of Viable Restoration Components..................... 76
Design Criteria and Engineering.............................. 78
Dredged Material......................................... 78
Dredged Material From Bends.............................. 78
Dredged Material From Bear Creek Relocation.............. 78
Dredged and Disposal Methods............................. 78
In-Water Placement....................................... 79
Jet-Spray Dredging....................................... 79
Hydraulic Pipeline Dredging.............................. 79
Disposal of Dredged Material............................. 79
Confined Upland Disposal Area............................ 79
Disposal Area in Navigation Cut #4....................... 80
Full Closure Structure................................... 81
Partial Closure Structure................................ 85
Design and Evaluation Flows.............................. 85
TABS-2 Hydraulic Model....................................... 87
Navigation Channel in Bends.............................. 88
Design Criteria.......................................... 88
Waterways Experiment Station Navigation Study............ 88
Modifications to Mill Creek.............................. 90
Project Maintenance...................................... 92
Section 5--Formulation of Preliminary Alternatives............... 93
Definition of Terms.......................................... 93
Components of Restoration Alternatives....................... 95
Cut and Bend #3.......................................... 95
Cut and Bend #4.......................................... 95
Mill Creek............................................... 95
Preliminary Restoration Alternatives......................... 98
Eliminate Relocation of Mouth of Bear Creek.............. 99
Benefit From Preliminary Alternatives........................ 99
Potential Increased Creek Flows.......................... 99
Preliminary Alternatives................................. 99
Flow into Bear Creek..................................... 99
Velocities in Bear Creek Approach Channel................ 101
Environmental Restoration Benefits....................... 102
Without Project Conditions............................... 102
Threatened and Endangered Species........................ 103
Aquatic Habitat.......................................... 103
Bottomland Hardwood...................................... 104
Habitat Unit Incremental Analysis........................ 104
Economic Analysis........................................ 104
Environmental Impacts of Restoration Alternatives............ 105
Loss of Aquatic Habitat Units............................ 105
Loss of Bottomland Hardwood Due to Project Construction.. 105
Environmental Values With and Without Restoration............ 107
Net Environmental Benefits................................... 107
Monitoring Plan.............................................. 110
Monitoring Requirements.................................. 110
Monitoring Plan.......................................... 110
Cost of Monitoring Plan.................................. 110
Real Estate Requirements..................................... 111
Environmental Assessment..................................... 111
Cost of Preliminary Alternatives............................. 111
Construction Costs....................................... 111
Dredging................................................. 111
Dredged Material Disposal Area........................... 112
Closure Structures....................................... 114
Bear Creek Approach Channel.............................. 114
Preconstruction Engineering and Design................... 114
Supervision and Administration........................... 114
Land and Damages......................................... 114
Cultural Resources Investigations........................ 115
Total Project First Costs................................ 115
Operation and Maintenance Costs.......................... 115
Monitoring Cost.......................................... 115
Total Project Costs...................................... 116
Benefits and Costs of Preliminary Alternatives............... 118
Section 6--Selection of Intermediate Alternatives................ 120
Summary of Preliminary Restoration Alternatives.............. 120
Screening of Preliminary Alternatives........................ 120
Alternative #1........................................... 123
Alternative #2........................................... 123
Alternative #18.......................................... 123
Alternative #22.......................................... 123
Alternative #32.......................................... 124
Alternative #24.......................................... 124
Alternative #36.......................................... 125
Alternative #16.......................................... 125
Selection of Intermediate Restoration Alternatives........... 126
Description of Intermediate Restoration Alternatives......... 127
Benefits and Costs of Intermediate Alternatives.............. 129
Section 7--Evaluation of Intermediate Alternatives............... 130
Introduction................................................. 130
Intermediate Restoration Alternatives........................ 130
Dredging and Disposal........................................ 133
Incremental Benefits and Costs............................... 133
Increased Flows in Creeks.................................... 135
Future Operation and Maintenance............................. 137
Overall Environmental Restoration............................ 137
Screening of Intermediate Alternatives....................... 137
Preliminary Screening of Intermediate Alternatives....... 138
Coordination............................................. 139
City of Savannah......................................... 139
U.S. Fish and Wildlife Service........................... 142
Conclusions.............................................. 142
Final Restoration Alternatives............................... 143
Total Project Cost of Final Restoration Alternatives......... 143
Impacts of Final Restoration Alternatives................ 144
Public Review on Final Restoration Alternatives.......... 144
Recommended Environmental Restoration Plan................... 144
Section 8--Final Restoration Plans............................... 145
Introduction................................................. 145
Recommended Environmental Restoration Plan................... 147
Description of Recommended Restoration Plan.............. 147
Cut and Bend #3.......................................... 147
Large Diversion Structure................................ 147
Realign Mouth of Bear Creek.............................. 147
Narrow Approach Channel.................................. 147
Plug Bend #3............................................. 147
Bank Stablization........................................ 148
Flows into Bear Creek.................................... 148
Cut and Bend #4.......................................... 148
Mill Creek............................................... 148
Dredging and Disposal of Dredged Material.................... 149
Benefits From Recommended Restoration Plan................... 149
Average Annual Habitat Units............................. 149
Bottomland Hardwood...................................... 149
Net Environmental Restoration Benefits................... 149
Environmental Impacts........................................ 150
No Action Alternative.................................... 150
Environmental Impacts of the Recommended Restoration Plan 150
Endangered Species....................................... 151
Water Quality............................................ 151
Suspended Solids In Disposal Area Weir Effluent.......... 151
Water Quantity........................................... 151
Other Water Quality Parameters........................... 151
Air Quality.............................................. 151
Sediment Quality......................................... 151
Sediment Analysis........................................ 151
Fishery Resources........................................ 151
Benthic Resources........................................ 152
Vegetation and Wildlife.................................. 152
Wetlands................................................. 152
Cultural Resources....................................... 152
Savannah National Wildlife Refuge........................ 152
Recreation............................................... 152
Secondary Impacts........................................ 152
Cumulative Impacts....................................... 152
Real Estate Requirements..................................... 153
Scope.................................................... 153
Real Estate Requirements................................. 153
Mill Creek Restoration................................... 154
Cut and Bend #3.......................................... 154
Bear Creek............................................... 154
Mitigation............................................... 155
Monitoring............................................... 155
Relocation of Highways, Roads, Railroads, Pipelines, and
Utilities.............................................. 155
Uniform Relocation Assistance Cost (P.L. 91-646), as
Amended................................................ 155
Navigational Servitude/Taking Analysis................... 155
Project Sponsor Responsibilities......................... 156
Government-Owned Property................................ 156
Real Estate Cost Estimate................................ 156
Real Estate Summary...................................... 157
Construction of Recommended Restoration Plan................. 158
Total Project Costs.......................................... 166
Total Project First Costs................................ 166
Contruction Costs........................................ 166
Real Estate Costs........................................ 167
Planning, Engineering, and Design........................ 167
Supervision and Administration........................... 167
Total Project Costs...................................... 167
Operation and Maintenance Costs.......................... 167
Monitoring Program....................................... 167
Interest During Construction............................. 168
Financial Analysis....................................... 169
Benefits and Costs of Recommended Restoration Plan........... 170
Cost Sharing................................................. 170
Views of Local Sponsor and Other Agencies.................... 172
City of Savannah......................................... 172
U.S. Fish and Wildlife Service........................... 172
Plan Implementation.......................................... 172
Federal Responsibility................................... 172
Non-Federal Responsibility............................... 172
Project Cooperation Agreement............................ 172
Items of Local Cooperation............................... 172
Financial Analysis Requirements.......................... 175
Section 9--Conclusions........................................... 177
Need for Environmental Restoration........................... 177
Options for Environmental Restoration........................ 177
Recommended Restoration Plan................................. 178
Section 10--Recommendations...................................... 180
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LIST OF APPENDICES
A Environmental Assessment....................................... 182
B U.S. Fish and Wildlife Service Coordination Report............. 373
C Pertinent Correspondence....................................... 437
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LIST OF TABLES
No.
1-1 Watersheds in Study Area...... 24
1-2 Navigation Cuts on the 28
Savannah River.
1-3 Study Team.................... 31
1-4 Report Contents............... 32
2-1 Waterborne Commerce on 34
Savannah River, Savannah to
Augusta.
2-2 Lower Savannah River Basin, 36
Current Land Use.
2-3 Lower Savannah River Basin, 37
Land Ownership.
2-4 Current and Projected 38
Population.
2-5 Average Precipitation at 40
Savannah Airport.
2-6 Average Streamflows, Savannah 41
River at Clyo, Georgia.
2-7 Responses to Navigation Survey 49
3-1 Loss of Bend Flow Capacity.... 51
3-2 Significance of Resources..... 58
4-1 Potential Restoration 75
Components Eliminated.
4-2 Environmental Restoration 77
Components.
4-3 Modifications to Mill Creek 90
Entrance.
5-4 Environmental Restoration 96
Components.
5-2 Preliminary Restoration 98
Alternatives.
5-3 Flow into Bear Creek, Partial 101
Closure of Cut #3.
5-4 Velocities in Bear Creek
Approach Channel, Partial
Closure of Cut #3............ 102
5-5 Losses in Bottomland Hardwood 106
from Project Construction.
5-6 Preliminary Restoration 108
Alternatives, Net
Environmental Benefits.
5-7 Preliminary Restoration 109
Alternatives, Net
Environmental Benefits.
5-8 Preliminary Restoration
Alternatives, Dredging
Volumes and Disposal Area
Capacities................... 112
5-9 Preliminary Restoration 113
Alternatives, Disposal of
Dredged Material.
5-10 Annual Cost of Monitoring 116
Program.
5-11 Preliminary Restoration 117
Alternatives, Total Project
Costs.
5-12 Preliminary Restoration
Alternatives, Summary of
Benefits and Costs........... 119
6-1 Preliminary Restoration 121
Alternatives, Net Benefits
and Costs.
6-2 Rationale for Selection of 126
Intermediate Alternatives.
6-3 Five Intermediate Restoration 127
Alternatives.
6-4 Description of Five 128
Intermediate Alternatives.
6-5 Benefits and Costs of 129
Intermediate Alternatives.
7-1 Description of Intermediate 131
Restoration Alternatives.
7-2 Benefits and Costs of 131
Intermediate Alternatives.
7-3 Intermediate Restoration
Alternatives, Losses to
Bottomland Hardwoods......... 132
7-4 Intermediate Restoration
Alternatives, Dredging and
Disposal of Dredged Material. 133
7-5 Intermediate Restoration
Alternatives, Incremental
Benefits and Costs........... 134
7-6 Intermediate Restoration 136
Alternatives, Restored Creek
Flows.
7-7 Alternatives #22 and #36, 144
Refined Total Project Costs.
8-1 Recommended Restoration Plan,
Flows and Velocities into
Bear Creek................... 148
8-2 Recommended Restoration Plan, 149
Net Restoration Benefits.
8-3 Recommended Restoration Plan, 153
Acreage Requirements.
8-4 Recommended Restoration Plan, 157
Real Estate Cost Estimate.
8-5 Recommended Restoration Plan, 159
Total Project Cost Summary.
8-6 Recommended Restoration Plan, 168
Total Project Costs.
8-7 Recommended Restoration Plan, 169
Financial Analysis.
8-8 Recommended Restoration Plan,
Net Restoration Benefits and
Project Costs................ 170
8-9 Recommended Restoration Plan,
Federal and Local Sponsor
Cost Sharing................. 171
9-1 Final Restoration Plans, Total 178
Costs and Cost Sharing.
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LIST OF FIGURES
ES-1 Lower Savannah River Basin, 7
Study Area.
ES-2 Recommended Environmental 11
Restoration Plan #22.
1-1 Lower Savannah River Basin.... 22
1-2 Lower Savannah River Basin
Environmental Restoration
Study, Study Area............ 23
1-3 Savannah River Below Augusta, 26
Federal Navigation Project.
2-1 Waterborne Commerce........... 35
2-2 Savannah National Wildlife 45
Refuge.
2-3 Savannah National Wildlife 46
Refuge within Study Area.
3-1 Without Project Conditions.... 53
4-1 Lower Savannah River Basin
Environmental Restoration
Study, Study Area............ 66
4-2 Bend Channel Configurations... 69
4-3 Increased Flow to Mouth of 73
Bear Creek.
4-4 Relocate Mouth of Bear Creek.. 74
4-5 Potential Upland Confined 82
Disposal Site.
4-6 Disposal Area in Navigation 83
Cut #4.
4-7 Full Closure Structure........ 84
4-8 Partial Closure Structure..... 86
4-9 Navigation Channel through 89
Bends.
4-10 Mill Creek Restoration........ 91
5-1 Preliminary Restoration 97
Alternatives, Channel Cross-
Sections.
5-2 Bear Creek Flow Options....... 100
6-1 Preliminary Restoration
Alternatives, Incremental
Benefits and Costs........... 122
7-1 Restored Flows with 140
Alternative #22.
7-2 Restored Flows with 141
Alternative #36.
8-1 Final Restoration Plan #22.... 146
9-1 Recommended Environmental 179
Restoration Plan, Alternative
#22.
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LIST OF PHOTOGRAPHS
No.
ES-1 Cut and Bend #3 Looking East.. 12
ES-2 Cut and Bend #4 Looking West.. 13
ES-3 Bend #3 Looking Downstream.... 14
ES-4 Bend #3 Looking Downstream 15
Lower Portion of Bend.
ES-5 Entrance to Bend #4........... 16
ES-6 East Side to Bend #3.......... 17
ES-7 Mill Creek.................... 18