WinTR-55 Modeling Multiple Sub-area Watersheds WinTR-55 Development Team

Sub-Area and Reach Concepts

Sub-area/Reach Concepts D C B E Watershed - system of sub-areas and reaches Sub-areas - watersheds that generate runoff Reaches - represent watershed flow paths (stream channels) or structures Reach 1c Reach 2e 12/6/2018 TR-55 Tutorial

Sub-area/Reach Concepts Watershed - system of sub-areas and reaches Sub-areas - generate runoff feed into the upstream end of reaches Reaches or Routing Elements- represent watershed stream flow paths or structures Channel Routing elements - Stream Reaches Structure Routing elements - Reservoir/Structure Reaches Watershed Outlet - downstream end of the watershed (required for all watersheds) 12/6/2018 TR-55 Tutorial

Reach 1a (storage routing) Schematics Sub-area A Reach 1a (storage routing) Sub-area B Sub-area C Reach 2c (Reach Routing) Legend: Storage Area Sub-Area Inflow Points Outlet 12/6/2018 TR-55 Tutorial

Data Requirements Identification Data - User, State, and County Dimensionless Unit Hydrograph Storm Data – for specific County/State Sub-area Data - Name, flows to reach/outlet, area, runoff curve number, & time of concentration Reach Data -Name, receiving reach/outlet, reach length, Manning’s “n”, friction slope, bottom width, average side slopes 12/6/2018 TR-55 Tutorial

Adding Sub-areas

Adding Sub-areas 12/6/2018 TR-55 Tutorial

Adding Stream Reaches and Developing Stream Reach Data

Adding Stream Reaches WinTR-55 Main Window Reach Data Window Reach Flow Path Window 12/6/2018 TR-55 Tutorial

Watershed Schematic 12/6/2018 TR-55 Tutorial Upper Main County Road Upper West Upper East Middle Main Lower West Lower East MainStem1 WestReach EastReach Lower Main MainStem2 Outlet 12/6/2018 TR-55 Tutorial

WinTR-55 Main Window 12/6/2018 TR-55 Tutorial

Adding Stream Reaches WinTR-55 Main Window Reach Data Window Reach Flow Path Window 12/6/2018 TR-55 Tutorial

Stream Reach Data Data compiled prior to input: Reach Name Name of receiving (or downstream) reach (could be Outlet) Cross-section data: Manning’s “n” Friction slope Bottom Width Average side slopes 12/6/2018 TR-55 Tutorial

Reach Data Window 12/6/2018 TR-55 Tutorial

Reach Data Window 12/6/2018 TR-55 Tutorial

Plotted Channel Rating 12/6/2018 TR-55 Tutorial

Computing Stream Reach Ratings Manning’s Equation for Channel Flow: Q = discharge (cu ft/s) r = hydraulic radius = A/pw A = cross-sectional flow area (sq ft) pw = wetted perimeter (ft) s = slope of hydraulic grade line (channel slope, ft/ft) n = Manning’s roughness coefficient for open channel flow 12/6/2018 TR-55 Tutorial

Trapezoidal Cross-Section 1 z BW TW D 12/6/2018 TR-55 Tutorial

Reach Data Window 12/6/2018 TR-55 Tutorial

Adding Stream Reaches WinTR-55 Main Window Reach Data Window Reach Flow Path Window 12/6/2018 TR-55 Tutorial

Reach Flow Path Window 12/6/2018 TR-55 Tutorial

Capabilities & Limitations Number of sub-areas 1 - 10 Number of reaches 0-10 Types of reaches Channel or Structure Channel Reach Routing Procedure Muskingum-Cunge 12/6/2018 TR-55 Tutorial

Sub-area and Reach Concepts Modeling Watersheds with Structures Sub-area and Reach Concepts

Sub-area / Reach Concepts Watershed - system of sub-areas and reaches Sub-areas - watersheds that generate runoff Reaches - represent watershed flow paths (stream channels) or structures Sub-area A N Stream Reach 2c Stream Reach 1b Outlet Structure Reach Pond Sub-area B Sub-area C 12/6/2018 TR-55 Tutorial

Sub-area/Reach Concepts Watershed - system of sub-areas and reaches Sub-areas - generate runoff feed into the upstream end of reaches Reaches or Routing Elements- represent watershed stream flow paths or structures Channel Routing elements - Stream Reaches Structure Routing elements - Reservoir/Structure Reaches Watershed Outlet - downstream end of the watershed (required for all watersheds) 12/6/2018 TR-55 Tutorial

Reach 1a (storage routing) Schematics Sub-area A Reach 1a (storage routing) Sub-area B Sub-area C Reach 2c (Reach Routing) Legend: Storage Area Sub-Area Inflow Points Outlet 12/6/2018 TR-55 Tutorial

Adding Structure Reaches and Developing Structure Data

Adding Structure Reaches WinTR-55 Main Window Reach Data Window Structure Data Window Reach Flow Path Window 12/6/2018 TR-55 Tutorial

WinTR-55 Main Window 12/6/2018 TR-55 Tutorial

Adding Structure Reaches WinTR-55 Main Window Reach Data Window Structure Data Window Reach Flow Path Window Next, proceed to the Reach Data Window where you will specify the name of the structure reach and the name of the structure itself. 12/6/2018 TR-55 Tutorial

Reach Data Window 12/6/2018 TR-55 Tutorial

Reach and Structure could be the same Name. Naming Reaches Reach and Structure could be the same Name. 12/6/2018 TR-55 Tutorial

Adding Structure Reaches WinTR-55 Main Window Reach Data Window Structure Data Window Reach Flow Path Window 12/6/2018 TR-55 Tutorial

Structure Data Window 12/6/2018 TR-55 Tutorial

Spillway Types Pipe Weir

Pipe Spillway To specify a pipe spillway, click the radio button  for Pipe under Spillway Type. The pipe spillway is the default, so when you open the Structure Data Window it will open to a pipe spillway configuration.  When specifying a pipe spillway, you may enter up to three different pipe diameters to test. The program will make as many runs through the data as pipe trial sizes are indicated. If you enter three pipe diameters the program will use the Trial #1 pipe diameter for the first run through, the Trial #2 pipe diameter for the second run, and the Trial #3 pipe diameter for the third run. This will be done for each storm event indicated, however the program will make no more than 3 runs for each storm even if multiple structures are included. In the event there are 2 or more structures in the watershed, all the Trial #1’s are run together, then all the Trial #2’s and then all the Trial #3’s.  You must also specify a Height from the pipe invert at the outlet end of the pipe to the spillway. You’ll see more clearly in the next illustrations how that is defined. One thing to keep in mind though is that this height must be at least ½ times the pipe diameter or greater. So, in the example of a 48” pipe diameter, a height from pipe invert at outlet to spillway crest elevation of no less than 2 feet could be specified. This is because of the way the program does the pipe flow computations we’ll look at in a moment. One thing to notice here is that the pipe diameter is specified in inches, while the height from the pipe invert at outlet to the principal spillway crest is in feet. In the case of SI units, the values are in units of millimeters and meters, respectively.  Once sufficient data is entered for the pipe diameter and height from the pipe invert at outlet to the spillway crest, WinTR-55 automatically computes a pipe flow rating for the structure. Pay attention to the note in red that says “Orifice Flow Assumed.” We’ll talk about that in just a moment. 12/6/2018 TR-55 Tutorial

Straight Pipe 12/6/2018 TR-55 Tutorial

Drop Inlet Pipe 12/6/2018 TR-55 Tutorial

Pipe Flow Equations where: g = gravity cd =0.6 Height, feet Headpipe,feet Stage, feet Dpipe ,inches Apipe,square feet Flowpipe,cfs 12/6/2018 TR-55 Tutorial

Pipe Flow Assumptions Short-tube approximation – assumes orifice flow through the pipe at all stages Reasonable for drop inlet configuration May be unreasonable for large straight pipes If not appropriate, use other routing models SITES WinTR-20 12/6/2018 TR-55 Tutorial

Pipe Flow Assumptions 12/6/2018 TR-55 Tutorial

Spillway Types Pipe Weir

Weir Spillway 12/6/2018 TR-55 Tutorial

Weir Configuration 12/6/2018 TR-55 Tutorial

Weir Flow Equations Stage, feet Flowweir, cfs where: Lweir = weir length, feet Stage, feet Flowweir, cfs 12/6/2018 TR-55 Tutorial

Weir Flow Assumptions Entry of a zero weir length indicates a 90° v-notch weir Other entry for weir length indicates a rectangular – having vertical sides - broad-crested weir 12/6/2018 TR-55 Tutorial

Plotting Structure Ratings 12/6/2018 TR-55 Tutorial

Structure Reach Routing

Storage-Indication Routing Method Estimates how the hydrograph changes as it flows through a structure DStorage = (inflow - outflow) * Dt 12/6/2018 TR-55 Tutorial

Structure Reach Routing 12/6/2018 TR-55 Tutorial

Structure Routing Plot 12/6/2018 TR-55 Tutorial

Adding Structure Reaches WinTR-55 Main Window Reach Data Window Structure Data Window Reach Flow Path Window 12/6/2018 TR-55 Tutorial

Reach Flow Path 12/6/2018 TR-55 Tutorial

Capabilities & Limitations Structure Routing Storage-Indication Structure Types Pipe or Weir Structure Trial Sizes 1-3 12/6/2018 TR-55 Tutorial

WinTR-55 Web Site Download latest WinTR-55 version Update notes http://wsi.nrcs.usda.gov/products/W2Q/H&H/Tools_Models/WinTR55.html Update notes WinTR-55 User Manual WinTR-55 Support Team e-mail address ug-orportlan-4-TR55 12/6/2018 TR-55 Tutorial

Development Team Claudia Hoeft NRCS, Washington DC Laurel Foreman NRCS, Iowa William Merkel NRCS-WNTSC, Maryland Helen Fox Moody NRCS-WNTSC, Maryland Quan D. Quan NRCS-WNTSC, Maryland Ralph Roberts ARS, Maryland John McClung NRCS-NWMC, Arkansas Al McNeill NRCS, South Carolina Jolyne Lee NRCS-NWCC, Oregon Don Woodward NRCS-retired Jon Werner NRCS-retired Roger Cronshey NRCS-retired 12/6/2018 TR-55 Tutorial