Title 210 – National Engineering Handbook Part 650 Engineering Field Handbook National Engineering Handbook Chapter 3 Hydraulics (210-650-H, 2nd Edition, Feb 2021) Title 210 – National Engineering Handbook Issued February 2021 In accordance with Federal civil rights law and U.S. Department of Agriculture (USDA) civil rights regulations and policies, the USDA, its Agencies, offices, and employees, and institutions participating in or administering USDA programs are prohibited from discriminating based on race, color, national origin, religion, sex, gender identity (including gender expression), sexual orientation, disability, age, marital status, family/parental status, income derived from a public assistance program, political beliefs, or reprisal or retaliation for prior civil rights activity, in any program or activity conducted or funded by USDA (not all bases apply to all programs). Remedies and complaint filing deadlines vary by program or incident. 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(210-650-H, 2nd Ed., Feb 2021) 630-3.i Title 210 – National Engineering Handbook Chapter 3 Hydraulics Table of Contents 650.0300 Introduction ....................................................................................................................... 3.1 650.0301 Unit Conversion ................................................................................................................ 3.1 650.0302 Hydrostatics ...................................................................................................................... 3.2 650.0303 Hydrokinetics .................................................................................................................. 3.12 650.0304 Pipe Flow ........................................................................................................................ 3.15 650.0305 Open-channel Flow ......................................................................................................... 3.34 650.0306 Weir Flow ....................................................................................................................... 3.46 650.0307 Orifice Flow .................................................................................................................... 3.56 650.0308 Flow Measurement .......................................................................................................... 3.59 650.0309 References ....................................................................................................................... 3.65 650.0310 Acknowledgements ......................................................................................................... 3.66 650.0311 Exhibits ........................................................................................................................... 3.68 Table of Figures Figure 3-1: Relationship of Pressure and Head ......................................................................... 3.3 Figure 3-2: Piezometer Tube in Pipeline ................................................................................... 3.4 Figure 3-3: Piezometer Data Plots to Determine Equipotential Lines ....................................... 3.5 Figure 3-4: Pressure on Submerged Surfaces ............................................................................ 3.6 Figure 3-5: Flashboards Pressure Diagram ................................................................................ 3.6 Figure 3-6: Headgate Pressure Diagram .................................................................................... 3.7 Figure 3-7: Material, % volume of structure, and unit weight ................................................... 3.8 Figure 3-8: Net weight of materials per cubic yard when unsubmerged, submerged and unsaturated, and submerged and saturated ............................................................................ 3.9 Figure 3-9: Box-Inlet Drop Spillway for Highway Culvert ..................................................... 3.10 Figure 3-10: Spread Footing for Box Culvert .......................................................................... 3.11 Figure 3-11: Tapered Pipe ....................................................................................................... 3.13 Figure 3-12: Energy Forms in Pipe Flow and Open-Channel Flow ......................................... 3.14 Figure 3-13: Values of Manning’s n for pipe flow .................................................................. 3.17 Figure 3-14: Values of Hazen-Williams C .............................................................................. 3.18 Figure 3-15: Pipe Flow Energy Relationships ......................................................................... 3.19 Figure 3-16. Drop Inlet Spillway through Earthen Embankment ............................................. 3.20 (210-650-H, 2nd Ed., Feb 2021) 630-3.ii Title 210 – National Engineering Handbook Figure 3-17. Corrugated Metal Pipe with Hooded Inlet through a Wetland Dike .................... 3.21 Figure 3-18: Field Diversion Discharging Below the Water Surface of a Stream ................... 3.22 Figure 3-19: Steep Pipeline Connecting Two Irrigation Reservoirs ........................................ 3.23 Figure 3-20: Sum of the loss coefficients ................................................................................ 3.23 Figure 3-21: Typical Road Culvert in Virginia ........................................................................ 3.24 Figure 3-22: Types of Culvert Inlets ....................................................................................... 3.25 Figure 3-23: Culvert inlet with angled wingwall (Photo courtesy of USDA-NRCS) .............. 3.26 Figure 3-24: Culvert flow conditions ...................................................................................... 3.27 Figure 3-25: Corrugated Metal Culvert Through Steam Crossing Embankment ..................... 3.28 Figure 3-26: Summary of Trial Solutions ................................................................................ 3.29 Figure 3-27: Elements of Culvert Flow ................................................................................... 3.30 Figure 3-28: Access Road Stream Crossing with Concrete Culvert ........................................ 3.32 Figure 3-29: Entrance loss coefficients for pipe culverts ......................................................... 3.33 Figure 3-30: Open-channel Flow in Maryland Stream ............................................................ 3.35 Figure 3-31: Open-channel Flow in New Mexico Irrigation Canal ......................................... 3.35 Figure 3-32: Types of Open-channel Flow .............................................................................. 3.37 Figure 3-33: n-Value Factors for streamflow .......................................................................... 3.39 Figure 3-34: Channel Energy Relationships ............................................................................ 3.40 Figure 3-35: Specific Energy Schematic ................................................................................. 3.42 Figure 3-36: Critical Flow Condition Definitions .................................................................... 3.42 Figure 3-37: Trapezoidal channel section ................................................................................ 3.43 Figure 3-38: Parabolic Section ................................................................................................ 3.44 Figure 3-39: Trapezoidal Section ............................................................................................ 3.45 Figure 3-40: Determination of discharge for a range of flow depths in a trapezoidal channel . 3.46 Figure 3-41: Weir in New Mexico Irrigation Ditch ................................................................. 3.46 Figure 3-42: Sharp-crested Weir ............................................................................................. 3.46 Figure 3-43: Broad-crested Weir ............................................................................................. 3.47 Figure 3-44: Ogee Weir ........................................................................................................... 3.47 Figure 3-45: Submerged Weir Schematic ................................................................................ 3.47 Figure 3-46: Contracted and Suppressed Weirs ......................................................................