Reservoir sedimentation handbook : design and management of dams, reservoirs, and watersheds for sustainable use

Proven strategies for controlling reservoir sediment All the state-of-the-art tools you need to extend water reservoir life by controlling sediment are packed into this hands-on resource. It helps you plan, design and manage both existing and proposed reservoirs and their associates watersheds. You'll learn to manage sediment for sustainable development. . .analyze suspended and deposited sediment. . .and estimate and measure erosion rates. Packed with clear illustrations and how-to examples, the book give you the know-how to: master sediment transport processes in reservoirs apply mathematical and physical models to analyze sediment processes route inflowing sediment through or around reservoir storage pools use turbid density currents to control sedimentation empty and scour sediments from a reservoir by means of hydraulic flushing and much more COVER PAGES......Page 1 Preface 1.04......Page 0 1.1 Need For Sediment Management......Page 11 1.2 ELEMENTS OF SEDIMENT MANAGEMENT......Page 14 1.3 HANDBOOK APPROACH......Page 15 2.1.1 Global Water Resources......Page 16 2.1.2 Water Scarcity......Page 17 2.2 IMPORTANCE OF RESERVOIRS......Page 20 2.3.1 Upstream Consequences......Page 23 2.3.2 Downstream Consequences......Page 25 2.4 CONCEPTS OF RESERVOIR LIFE......Page 28 2.5 GEOMORPHIC STAGES OF RESERVOIR LIFE......Page 29 2.6 RATE OF STORAGE LOSS......Page 31 2.7 CONCEPTS OF SUSTAINABLE DEVELOPMENT......Page 32 2.8 RESERVOIRS AS NONRENEWABLE RESOURCES......Page 35 2.9 ECONOMICS AND SUSTAINABILITY......Page 37 2.10 CRITERIA-BASED APPROACH TO SUSTAINABILITY......Page 38 2.11.1 Sedimentation Assessment......Page 39 2.11.4 Screening of Sediment Management Alternatives......Page 40 2.11.6 Design, Implementation, and Monitoring of ControlMeasures......Page 41 2.12 POPULATION AND FOOD SUSTAINABILITY......Page 42 3.1.1 Dams in Antiquity......Page 44 3.1.2. Modern Dam Construction......Page 46 3.2.2 Embankment Dams......Page 47 3.2.3 Concrete Dams......Page 48 3.3.1 Reservoir Size......Page 49 3.3.2 Pool Geometry......Page 50 3.3.4 Stage-Storage Relationships......Page 51 3.3.5 Types of Reservoir Operation......Page 52 3.4 OUTLETS AND GATES......Page 54 3.5.2 Types of Hydraulic Turbines......Page 55 3.5.4 Sediment Impact on Tailwater......Page 57 3.6.2 Abrasion of Concrete Structures......Page 59 3.6.3 Cavitation......Page 60 3.8 RESERVOIR YIELD......Page 62 3.8.2 Gould's Gamma Method for Estimating Yield......Page 63 3.8.4 Hydrologic Time Series......Page 65 3.8.5 Sedimentation Effect on Yield......Page 66 4.1.2 Hydrologic Size and Loading Rate......Page 68 4.1.4 Geometry and Longitudinal Gradients......Page 70 4.2.1 Stratification......Page 71 4.2.2 Seasonality of Stratification......Page 72 4.2.3 Density of Water......Page 73 4.3.1 Horizontal Focusing......Page 74 4.3.2 Vertical Focusing......Page 75 4.4 SELECTIVE WITHDRAWAL......Page 76 4.5 LIGHT AND TRANSPARENCY......Page 78 4.6.2 Diurnal Variations in Dissolved Oxygen......Page 79 4.6.3 Productivity......Page 80 4.6.5 Trophic Status......Page 81 4.7.1 The Concept of Limiting Nutrients......Page 83 4.7.2 Phosphorus......Page 84 4.7.3 Nitrogen......Page 86 4.8 GRADIENTS, SEDIMENTATION, AND BIOLOGICAL PROCESSES......Page 87 4.9 CLOSURE......Page 89 5.1.1. Size of Sediment Grains......Page 90 5.1.2. Particle Shape and Roundness......Page 91 5.1.3. Grain Size Distribution......Page 93 5.1.4. Classification by Mode of Transport......Page 94 5.2.3 Clay and Clay Flocculation......Page 96 5.3.1 Sediment Density and Weight......Page 98 5.3.3 Angle of Repose......Page 100 5.4.1 Void Space......Page 101 5.4.2 Sediment Concentration......Page 102 5.5.1 Fluid Viscosity......Page 103 5.5.2 Reynolds Number......Page 104 5.5.5 Simplified Equations for Fall Velocity......Page 105 5.5.7 Sweep Flocculation and Hindered Settling......Page 107 5.6.1 Filtration Method......Page 110 5.6.4 Sediment Volume......Page 111 5.7 LABORATORY ANALYSIS OF SEDIMENT SIZE......Page 112 5.7.1 Use of Deflocculants......Page 113 5.7.4 Dry Sieving......Page 114 5.7.6 Direct Measurement of Nominal Diameter......Page 115 5.7.10 Hydrometer......Page 116 6.1 CONCEPTS AND DEFINITIONS......Page 118 6.2.2 Off-Site Impacts......Page 123 6.3 EROSION RATE......Page 124 6.4.1 Interrill Erosion......Page 125 6.4.2 Rainfall......Page 126 6.4.3 Rill Erosion......Page 127 6.4.4 Size of Eroded Particles......Page 128 6.5.1 Gully Erosion Process......Page 129 6.5.2 Quantification of Gully Erosion......Page 131 6.6.1 Processes......Page 132 6.6.2 Quantifying Channel Erosion......Page 133 6.7 SLOPE FAILURE......Page 134 6.8 FIELD MEASUREMENT OF EROSION......Page 135 6.8.3 Experimental Watersheds......Page 136 6.8.4 Measurement Equipment......Page 137 6.8.5 Simulated Rainfall......Page 138 6.8.6 Other Methods......Page 139 6.9 EROSION MODELING WITH USLE AND RUSLE......Page 140 6.10 EROSION MODELING USING WEPP......Page 142 6.11.1 Basic Delivery Ratio Concepts......Page 143 6.11.2 Causes of Reduced Sediment Delivery......Page 144 6.11.4 Variation in Delivery Ratio......Page 146 6.11.5 Estimating Sediment Delivery Ratio......Page 148 6.11.6 Sediment Sorting and Enrichment......Page 150 6.12 CLOSURE......Page 153 7.1 SPATIAL VARIABILITY IN SEDIMENT YIELD......Page 154 7.2.2 Within-Storm Variation in Suspended Load......Page 158 7.2.5 Long-Term Changes in Sediment Yield Due to Disturbances......Page 163 7.2.6 Changes in Long-Term Yield Due to Geomorphic Factors......Page 168 7.3.1 Reservoir Resurvey......Page 171 7.3.2 Fluvial Monitoring......Page 173 7.3.3 Uncertainty in Sediment Yield......Page 174 7.3.4 Quantifying Interannual Variability in Sediment Load......Page 175 7.4 SEDIMENT RATING CURVES......Page 176 7.4.1 Fitting Sediment Rating Curves......Page 177 7.4.3 Mathematical Curve Fitting......Page 178 7.4.4 Rating Curve Example......Page 180 7.5.1 Time-Series Sediment Rating Curve Technique......Page 181 7.5.4 Estimating Bed Load......Page 182 7.6.1 Regional Rate of Storage Loss......Page 183 7.6.2 Regional Regression Relationship......Page 184 7.6.3 PSIAC Method......Page 185 7.6.4 Sediment Yield Maps......Page 188 7.6.5 Erosion Modeling......Page 189 7.7 GIS AND EROSION PREDICTION......Page 190 7.8.2 Direct Measurement......Page 192 7.8.4 Sediment Fingerprinting......Page 193 7.9 CLOSURE......Page 196 8.1.1 Stream Order......Page 198 8.1.3 Stream Patterns......Page 199 8.1.4 Meandering and Stream Migration......Page 200 8.1.5 Lane's Balance......Page 202 8.1.6 Differences between Sand and Gravel Bed Streams......Page 203 8.1.7 Armoring......Page 204 8.2 SUSPENDED-SEDIMENT SAMPLING......Page 205 8.2.2 Isokinetic Sampling......Page 206 8.2.3 Sampling Location......Page 207 8.2.5 Depth-Integrating Sampler......Page 208 8.2.6 Point-Integrating Sampler......Page 209 8.2.7 Sampling in Transverse Direction......Page 210 8.3.1 Equipment Description......Page 211 8.3.2 Sampler Intake Placement......Page 212 8.3.3 Sampling Depth......Page 213 8.3.4 Nozzle Orientation......Page 214 8.4.1 Application......Page 215 8.4.3 Relationship between Turbidity and Suspended Solids......Page 216 8.4.4 Limitations of Turbidity Data......Page 218 8.5.1 Statistically Based Strategies for Pumped Samplers......Page 219 8.5.2 Sampling Strategies for Turbidimeters......Page 220 8.7.1 Bed Load Transport......Page 221 8.7.2 Bed Load Sampling......Page 222 8.7.3 Continuous Bed Load Measurement......Page 223 8.8.2 The Sampling Problem in Gravel-Bed Streams......Page 224 8.8.3 Selection of Sampling Areas......Page 225 8.8.4 Selection of Sampled Stones......Page 226 8.8.6 Frequency by Size Class......Page 227 8.8.9 Truncated Samples......Page 228 8.9 BED MATERIAL GRAIN SIZE CONVERSION FACTORS......Page 229 8.9.1 Areal Count to Bulk Sieve Conversion......Page 231 8.10.1 Sampling Precision and Accuracy......Page 232 8.10.2 Sampling Equipment......Page 233 8.10.3 Number of Sampling Points......Page 234 8.10.5 Rating Curves......Page 236 8.11CLOSURE......Page 237 HYDRAULICS OF SEDIMENT TRANSPORT......Page 239 9.1 DEFINITIONS AND UNITS......Page 240 9.2.2 Manning Equation......Page 242 9.3.1 Grain Roughness......Page 243 9.3.2 Estimating Total Roughness......Page 244 9.3.3 Cowan's Method......Page 246 9.3.4 Effect of Vegetation on Flow Resistance......Page 251 9.5.1 Reynolds Number......Page 253 9.5.4 Vertical Velocity Distribution......Page 256 9.6 VERTICAL DISTRIBUTION OF SEDIMENT CONCENTRATION......Page 258 9.7 INITIATION OF MOTION......Page 259 9.7.1 Bed Shear or Tractive Force......Page 260 9.7.4 Shields Diagram......Page 261 9.7.5 Velocity Criteria......Page 264 9.7.6 Annandale's Erodibility Index Method......Page 265 9.7.7 Example 9.1......Page 268 9.7.8 Example 9.2......Page 269 9.8.1 Shear Stress Distribution......Page 270 9.8.2 Slope Stability......Page 271 9.9.1 Ackers and White......Page 272 9.9.3 Yang's Equation for Sand Transport......Page 274 9.9.5 Yang's Modification for Water-Sediment Mixtures......Page 276 9.10 HYPERCONCENTRATED FLOW......Page 277 9.11.1 Importance of Cohesive Sediments......Page 278 9.11.2 Settling and Compaction of Cohesive Sediment......Page 280 9.11.3 Rheology of Cohesive Sediment Mixtures......Page 282 9.11.4 Laboratory Testing of Cohesive Sediment......Page 283 9.11.5 Erosion Thresholds for Cohesive Sediment......Page 285 9.11.7 Deposition Rate of Cohesive Sediment......Page 287 9.11.8 Angle of Repose......Page 288 9.11.9 Settling of Individual Coarse Particles......Page 289 9.12 CLOSURE......Page 290 10.2 GENERALIZED DEPOSITION PATTERNS......Page 292 10.2.2 Longitudinal Deposit Geometry......Page 293 10.2.3 Lateral Deposition Patterns......Page 294 10.2.5 Influence of Regulation Regime......Page 296 10.3.1 Delta Deposition Patterns......Page 297 10.3.2 Slope of Delta Deposits......Page 302 10.4.2 Horizon Tracing Using 137Cesium......Page 304 10.4.4 Spud Surveys......Page 305 10.4.5 Sedimentation Plates......Page 306 10.5.2 Survey Intervals......Page 307 10.5.4 Survey Errors......Page 308 10.6.1 Contour Survey Methods......Page 309 10.7.1 Location of Ranges......Page 311 10.7.4 Average End Area......Page 313 5.1.1. Constant Factor Method......Page 314 EFFICIENCY......Page 315 10.8.1 Brune Curve......Page 317 10.8.2 Churchill Method......Page 318 10.9.1 Compaction Processes......Page 319 10.9.3 Lara-Pemberton Method for Initial Bulk Density......Page 320 10.9.4 Sediment Compaction......Page 322 10.10.2 Area-increment and Empirical Area Reduction Methods......Page 323 10.11 SAMPLING SEDIMENT DEPOSITS......Page 330 10.11.2 Sampling for Chemical Contaminants......Page 331 10.11.4 Gravity Corers......Page 332 10.12 CLOSURE......Page 333 11.2 MODELING PROTOCOL......Page 334 11.3 CONCEPTUAL MODELING......Page 337 11.4 NUMERICAL MODELING......Page 339 11.5.1 Hydrology......Page 340 11.5.3 Selection of Transport Equation......Page 341 11.5.4 Calibration......Page 344 11.6.1 HEC-6......Page 347 11.6.2 GSTARS......Page 349 11.6.3 FLUVIAL......Page 350 11.6.5 SSIIM......Page 351 11.7 PHYSICAL MODELING......Page 352 11.7.1 Applicability of Physical Models......Page 354 11.9 EXAMPLES OF PHYSICAL MODEL SCALING AND OPERATION......Page 355 11.9.1 Problem Identification......Page 357 11.9.2 Model Type and Scales......Page 358 11.9.5 Calibration......Page 359 11.9.8 Validation......Page 360 11.10 CLOSURE......Page 361 12.1.1 Applicability......Page 362 12.1.2 Limitations......Page 363 12.1.3 Additional Sources of Information......Page 364 12.2.1 Technical Strategies for Erosion Control......Page 365 12.2.3 Types of Sediment Trapping Structures......Page 368 12.2.5 Sediment Trapping versus Erosion Control......Page 369 12.3.1 What Causes Erosion?......Page 370 12.3.2 Identifying and Prioritizing Sediment Sources......Page 371 12.3.3 Identification of Partners......Page 372 12.3.4 Economic Costs, Benefits, and Erosion Control Strategies......Page 373 12.4 EROSION CONTROL MEASURES ON FARMS......Page 374 12.4.4 Conservation Tillage......Page 375 12.4.5 Grassed Waterways......Page 376 12.4.7 Contour-Grassed Hedges......Page 377 12.5.2 Criteria for Successful Erosion Control......Page 380 12.6 EROSION CONTROL ON MECHANIZED FARMS......Page 382 12.7 EROSION CONTROL ON SUBSISTENCE FARMS......Page 383 12.7.2 Terracing......Page 384 12.7.4 The World Neighbors Program in Honduras......Page 385 12.7.5 Implementation in Ecuador......Page 386 12.8.1 Definitions......Page 387 12.8.3 Yarding Methods......Page 388 12.8.5 Riparian Buffer Strips......Page 390 12.8.6 Logging Roads......Page 391 12.9 RESERVOIR SHORELINE EROSION......Page 392 12.10.2 Basic Strategy for Gully Control......Page 393 12.10.3 Check Dams......Page 394 12.10.4 Vegetative Control of Gullying......Page 396 12.11 EROSION CONTROL STRATEGIES FOR RANGELAND......Page 397 12.12 EROSION CONTROL STRATEGIES IN URBANIZING AREAS......Page 399 12.13.1 Design Philosophy......Page 400 12.13.2 Detention Basin Geometry......Page 402 12.13.3 Design Computations for Plug Flow......Page 404 12.13.5 Dewatering Orifice......Page 409 12.13.6 Weir Discharge......Page 410 12.14.1 Debris Basin Configurations......Page 411 12.14.2 Sediment Trapping by Debris Basins......Page 412 12.14.3 Debris Basin Cleanout......Page 414 12.15 CLOSURE......Page 415 8B13.1.2 Classification of Techniques......Page 417 9B13.1.3 Advantages and Disadvantages......Page 418 12B13.2.3 Partial Drawdown at Three Gorges Project......Page 419 13B13.2.4 Seasonal Emptying of Reservoir......Page 422 14B13.3.1 Technique......Page 423 15B13.3.2 Sediment Balance by Flood Routing......Page 424 16B13.3.3 Sediment Adjustments under Routing......Page 425 18B13.4.3 Operational Sequence......Page 426 20B13.4.5 Hydrograph Prediction......Page 428 22B13.5.2 Operational Example......Page 429 24B13.6.2 Application......Page 431 25B13.7.1 Technique......Page 432 26B13.7.2 Application......Page 433 27B13.7.3 Computation of Reservoir Yield and Sediment Exclusion......Page 434 4B13.8 SUBSURFACE RESERVOIR......Page 436 5B13.9 SEDIMENT EXCLUSION......Page 437 30B13.9.3 Gravel Sluice......Page 438 31B13.9.4 Intakes at Large Dams......Page 439 34B13.10.2 Reservoirs in Series......Page 440 7B13.11 CLOSURE......Page 441 14.1 INTRODUCTION......Page 442 14.2.1 Variation in Density......Page 444 14.2.3 Plunging Flow......Page 445 14.2.5 Turbidity Current Forward Motion......Page 447 14.2.6 Turbidity Current Behavior at a Bend......Page 448 14.2.7 Submerged Muddy Lake......Page 449 14.3.2 Muddy Lake Deposits......Page 450 14.5.1 Blockage of Low-Level Outlets......Page 454 14.5.2 Turbidity Currents at a Confluence......Page 455 14.6 VERTICAL STRUCTURE OF TURBIDITY CURRENTS......Page 457 14.7.3 Timing and Duration of Releases......Page 459 14.7.4 Discharge......Page 460 14.7.5 Height of Aspiration......Page 462 14.8.1 Computational Strategy......Page 464 14.8.3 Grain Size That Can Be Transported......Page 465 14.9 MONITORING DENSITY CURRENT MOVEMENT......Page 466 14.10 CLOSURE......Page 467 15.1.2 Classification of Techniques......Page 469 15.1.3 Applications......Page 470 15.1.4 Limitations......Page 471 15.2.2 Accumulation of Coarse Sediment Deposits during Flushing......Page 472 15.2.3 Channel Formation and Maintenance......Page 474 15.2.4 Flushing Procedures......Page 476 15.3.1 Empty Flushing during Flood Season......Page 477 15.4.1 Pressure Flushing......Page 478 15.4.2 Flushing with High-Level Outlet......Page 481 15.5.1 Slumping at the Dam......Page 483 15.5.2 Slope Failure......Page 485 15.5.3 Retrogressive Erosion......Page 486 15.6 VARIATION IN EROSION RATE AND SEDIMENT RELEASE......Page 487 15.6.2 Between-Event Variability......Page 488 15.6.3 Effect of Discharge on Erosion Rate......Page 489 5.1.1. 15.7.1 Definition......Page 490 15.7.2 Flushing Efficiency with Partial Drawdown......Page 491 15.7.3 Flushing Efficiency with Emptying......Page 492 15.8.1 Lateral Erosion......Page 493 15.8.2 Longitudinal Erosion......Page 494 15.8.3 Flow Diversion......Page 495 15.9 STORAGE HISTORY CURVES......Page 496 15.10 SCOUR CONE GEOMETRY......Page 497 15.11 COMPARTMENTED AND MULTIPLE RESERVOIRS......Page 498 15.12 PLANNING AND IMPLEMENTATION......Page 499 15.12.2 Scheduling of Flushing......Page 500 15.12.4 Sediment Release and Concentration......Page 501 15.13 LONG-TERM STORAGE CAPACITY......Page 504 15.14 CLOSURE......Page 506 16.1 INTRODUCTION......Page 507 16.2 DRY EXCAVATION......Page 508 16.2.2 Cogswell Reservoir......Page 509 16.3.1 Hydraulic Suction Dredges......Page 511 16.3.2 Siphon Dredge......Page 514 16.3.4 Cable-Suspended Dredge Pumps......Page 515 16.3.6 Sediment Removal by Explosives......Page 516 16.4 CONSIDERATIONS FOR RESERVOIR DREDGING......Page 517 16.4.2 Dredging Equipment......Page 518 16.4.3 Pipeline System......Page 520 16.4.4 Disposal Site......Page 521 16.4.5 Long-Term Use and Sustainable Dredging......Page 523 16.4.6 Dredging Contracts......Page 524 16.4.7 Permit Requirements......Page 526 16.5.1 Lake Springfield, Illinois......Page 527 16.5.2 Valdesia Reservoir, Dominican Republic......Page 528 16.5.3 Bai-Ho Reservoir, Taiwan......Page 530 16.6.1 Volume for Initial Storage......Page 531 16.6.2 General Containment Area Considerations......Page 532 16.7 COLUMN SETTLING TESTS......Page 533 16.7.1 Column Test Procedure......Page 534 16.7.2 Zone Settling Test......Page 536 16.7.3 Compression Settling Test......Page 537 16.7.4 Achievement of Strict Effluent Standards......Page 538 16.7.5 Hydraulic Efficiency......Page 539 16.7.6 Weir Length......Page 540 16.8.1 Flow Regimes......Page 541 16.9 PIPELINE HEAD LOSS......Page 544 16.9.1 Friction Losses by Slurry Density Approach......Page 545 16.9.3 Turner's Friction Loss Graph......Page 546 16.10 CLOSURE......Page 548 17.1 INTRODUCTION......Page 549 17.2 DAM REMOVAL OPTIONS......Page 550 17.2.3 Complete Dam Removal......Page 551 17.2.4 Staged Breaching......Page 552 17.3 SEDIMENT MANAGEMENT OPTIONS......Page 553 17.3.1 Leave Sediment in Place......Page 554 17.3.2 Natural Erosion......Page 555 17.3.3 Channeling and Stabilization......Page 556 17.4.1 Water and Sediment Quality......Page 558 17.4.2 Fluvial Morphology......Page 560 17.4.4 Flood Management......Page 561 17.4.8 Cost......Page 562 17.5.2 Stronach Dam......Page 563 17.5.3 North Avenue Dam, Milwaukee, Wisconsin......Page 564 17.5.4 Glines Canyon and Elwha Hydroelectric Dams, Washington State......Page 567 17.6 CLOSURE......Page 573 18.1 INTRODUCTION......Page 574 18.2.1 Dams and Environmental Impacts......Page 575 18.2.2 Economic Quantification of Environmental Impacts......Page 576 18.2.3 Hydroperiod Modification......Page 578 18.2.4 Environmental Consequences of Sediment and Its Management......Page 580 18.2.5 Morphologic Impact Downstream of Dams......Page 582 18.3 ENVIRONMENTAL IMPACTS OF SEDIMENT ROUTING......Page 587 18.3.3 Seasonally Empty Reservoir......Page 589 18.3.4 Sediment Routing on Isar River......Page 590 18.4.1 Water Quality during Reservoir Emptying......Page 592 18.4.2 Fisheries Impacts......Page 593 18.4.3 Predicting Downstream Water Quality......Page 594 18.4.4 Reservoir Ecosystem......Page 595 18.4.6 Timing, Coordination, and Public Relations......Page 596 18.4.7 Water Quality Mitigation Measures for Flushing......Page 598 18.4.8 Monitoring......Page 599 18.4.9 Flushing at Spencer Dam, Nebraska......Page 600 18.5.2 Grain Feeding in the Rhine River......Page 602 18.6.1 Importance of Gravel Flushing......Page 604 18.6.3 Planning Flushing Flows......Page 606 18.6.4 Analytical Flushing Flow Computations for Gravel Cleansing......Page 607 18.6.5 Gravel Flushing in Trinity River, California......Page 608 18.7 CLOSURE......Page 609 19.1.1 Project Description......Page 610 19.2.1 Operational Procedures......Page 613 19.2.2 Sedimentation Studies at the Reservoir......Page 617 19.3.1 Rating Curve Analysis......Page 618 19.3.2 Analysis of Computational Increment......Page 620 19.3.5 Critical Discharge Classes......Page 621 19.3.6 Turbidity Measurement......Page 622 19.3.7 Interpretation of Turbidity Data......Page 625 19.4 SEDIMENT DEPOSITION AND EROSION......Page 628 19.4.3 Grain Size Analysis......Page 629 19.4.5 Side-Scan Sonar......Page 630 19.4.6 Subbottom Profiler......Page 631 19.5.1 Erosion Processes Observed during Flushing......Page 632 19.5.2 Sediment Release during Flushing......Page 633 19.6 SEDIMENT BUDGET......Page 636 19.7 CLOSURE......Page 637 20.1 PROJECT HISTORY......Page 638 20.2 HYDROLOGY......Page 641 20.3.1 Sediment Yield......Page 642 20.3.2 Sediment Deposits......Page 644 20.3.4 Rate of Storage Loss......Page 648 20.3.5 Trends in Sediment Yield......Page 652 20.4.4 Venting Turbid Density Currents......Page 653 20.5 MODELING OF SEDIMENT ROUTING......Page 654 20.5.3 Model Calibration......Page 655 20.5.4 Modeling Results......Page 656 20.6.1 Operational Constraints......Page 657 20.6.2 Model Development......Page 658 2.6.5 Model Operation......Page 659 20.7.1 Dredging Volume......Page 660 20.7.3 Sediment Sampling......Page 661 20.9 CLOSURE......Page 662 21.1 INTRODUCTION......Page 663 21.2 ALTERNATIVES CONSIDERED......Page 664 21.3 CONFIGURATION OF LOW-LEVEL OUTLET......Page 665 21.4 FLUSHING OPERATIONS......Page 666 21.5 DOWNSTREAM IMPACTS......Page 670 22.1 INTRODUCTION......Page 673 22.2.1 Site Description......Page 674 22.2.2 Geomorphology......Page 676 22.2.3 Sediment Management History......Page 677 22.3.2 Erosion History......Page 678 22.3.4 Coordinated Resources Management Group......Page 680 22.4.1 Red Clover Creek Demonstration Project......Page 682 22.4.2 Big Flat Meadow Restoration Project......Page 686 22.5 COST AND BENEFIT OF WATERSHED RESTORATION......Page 687 22.5.1 Overview of Project Costs......Page 688 22.5.2 PG&E Economic Justification for Watershed Protection Activities......Page 689 22.7 RESERVOIR DREDGING......Page 691 22.8 SEDIMENT ROUTING......Page 693 22.8.2 Physical Modeling......Page 694 22.8.3 Numerical Modeling......Page 695 22.8.4 Selected Project Configuration......Page 697 22.9 SEDIMENT PROBLEMS AT POE DAM......Page 698 23.2.1 Dam and Reservoir......Page 700 23.2.2 Water and Sediment Inflow......Page 701 23.2.3 Sediment Deposits......Page 704 23.2.4 Turbid Density Currents......Page 705 23.3.1 Hydraulic Dredging......Page 706 23.3.4 Venting Turbid Density Currents......Page 707 23.3.6 Emptying and Flushing......Page 708 23.4.1 Reservoir Operation......Page 709 23.4.2 Sheet Erosion......Page 712 23.4.5 Outflow Sediment Concentration......Page 713 23.5 LATERAL EROSION BY PIPING......Page 716 23.6 DIVERSION CHANNEL TECHNIQUE......Page 717 23.6.1 Components of the System......Page 718 23.6.4 Operational Results......Page 719 23.6.5 Prediction of Channel Width......Page 723 23.7 ECONOMIC ANALYSIS......Page 724 23.8 CLOSURE......Page 726 24.1 INTRODUCTION......Page 727 24.2 HYDROLOGIC SETTING......Page 728 24.3 SUMMARY OF SEDIMENT CONTROL MEASURES......Page 730 24.4.1 Deposition and Flushing......Page 736 24.5 DELTA DEPOSITION AND EROSION......Page 737 24.6 TURBIDITY CURRENTS......Page 739 24.7 DEPOSITION ALONG WEI RIVER......Page 740 24.7.1 Backwater Deposition......Page 741 24.7.2 Local Deposition from Luo River......Page 742 24.8 RETROGRESSIVE EROSION......Page 743 24.9 SEDIMENT DISCHARGE DOWNSTREAM......Page 744 24.10 CLOSURE......Page 747 25.2 SITE DESCRIPTION......Page 748 25.3 SEDIMENT MANAGEMENT STRATEGIES......Page 752 25.4 WARPING......Page 753 25.5 DEPOSITION PATTERNS......Page 754 25.6.2 Detention Flushing......Page 755 25.7 TURBIDITY CURRENT VENTING......Page 758 25.8 LATERAL EROSION......Page 759 25.9 VARIATION IN SEDIMENT RELEASE EFFICIENCY......Page 762 25.9.2 Flood Detention Flushing......Page 764 25.10 CLOSURE......Page 767 REFERENCES......Page 768 A. PROPERTIES OF WATER, INTERNATIONAL UNITS......Page 799 D. UNIT PREFIXES......Page 800 F. INTERNATIONAL AND DERIVED UNITS OF MEASURE......Page 801 G. UNITS OF MEASURE IN BRITISH OR U.S. CONVENTIONAL UNITS (FPS SYSTEM)......Page 802 H. TABLE OF UNIT CONVERSION FACTORS......Page 803 J. STREAM POWER......Page 804