Conduits are pipes or channels that move water from one node to another in the conveyance system. Their cross-sectional shapes can be selected from a variety of standard open and closed geometries. Irregular natural cross-section shapes are also supported, as are user-defined closed shapes.
The input parameters for a Conduit are listed in the table below:
| Field | Description |
| Name | User-assigned conduit name. |
| Inlet Node | Name of node on the inlet end of the conduit (which is normally the end at higher elevation). |
| Outlet Node | Name of node on the outlet end of the conduit (which is normally the end at lower elevation). |
| Shape | Click the x-Section Attributes tab to edit the geometric properties of the conduit's cross section. |
| Max. Depth | Maximum depth of the conduit's cross section (feet or meters). |
| Length | Conduit length (feet or meters). |
| Roughness | Manning's roughness coefficient. |
| Inlet Offset | Depth or elevation of the conduit invert above the node invert at the inlet end of the conduit (feet or meters). |
| Outlet Offset | Depth or elevation of the conduit invert above the node invert at the outlet end of the conduit (feet or meters). |
| Initial Flow | Initial flow in the conduit at the start of the simulation (flow units). |
| Maximum Flow | Maximum flow allowed in the conduit (flow units) - use 0 or leave blank if not applicable. |
| Entry Loss Coeff. | Head loss coefficient associated with energy losses at the entrance of the conduit. For culverts, refer to Culvert Inlet Loss Coefficients table. |
| Exit Loss Coeff. . | Head loss coefficient associated with energy losses at the exit of the conduit. For culverts, use a value of 1.0. |
| Avg. Loss Coeff. | Head loss coefficient associated with energy losses along the length of the conduit. |
| Seepage Loss Rate | Rate of Seepage loss into surrounding Soil (in/hr) or (mm/hr) |
| Flap Gate | YES if a flap gate exists that prevents backflow through the conduit, or NO if no flap gate exists. |
| Culvert Code | Code number of inlet geometry if conduit is a culvert subject to possible inlet flow control -- leave blank otherwise. Refer to the table below for Culvert Code Numbers. |
Culvert Code Numbers
Circular Concrete
1 Square edge with headwall
2 Groove end with headwall
3 Groove end projecting
Circular Corrugated Metal Pipe
4 Headwall
5 Mitered to slope
6 Projecting
Circular Pipe, Beveled Ring Entrance
7 45 deg. bevels
8 33.7 deg. bevels
Rectangular Box; Flared Wingwalls
9 30-75 deg. wingwall flares
10 90 or 15 deg. wingwall flares
11 0 deg. wingwall flares (straight sides)
Rectangular Box;Flared Wingwalls and Top Edge Bevel:
12 45 deg flare; 0.43D top edge bevel
13 18-33.7 deg. flare; 0.083D top edge bevel
Rectangular Box, 90-deg Headwall, Chamfered / Beveled Inlet Edges
14 chamfered 3/4-in.
15 beveled 1/2-in/ft at 45 deg (1:1)
16 beveled 1-in/ft at 33.7 deg (1:1.5)
Rectangular Box, Skewed Headwall, Chamfered / Beveled Inlet Edges
17 3/4" chamfered edge, 45 deg skewed headwall
18 3/4" chamfered edge, 30 deg skewed headwall
19 3/4" chamfered edge, 15 deg skewed headwall
20 45 deg beveled edge, 10-45 deg skewed headwall
Rectangular Box, Non-offset Flared Wingwalls, 3/4" Chamfer at Top of Inlet
21 45 deg (1:1) wingwall flare
22 8.4 deg (3:1) wingwall flare
23 18.4 deg (3:1) wingwall flare, 30 deg inlet skew
Rectangular Box, Offset Flared Wingwalls, Beveled Edge at Inlet Top
24 45 deg (1:1) flare, 0.042D top edge bevel
25 33.7 deg (1.5:1) flare, 0.083D top edge bevel
26 18.4 deg (3:1) flare, 0.083D top edge bevel
Corrugated Metal Box
27 90 deg headwall
28 Thick wall projecting
29 Thin wall projecting
Horizontal Ellipse Concrete
30 Square edge with headwall
31 Grooved end with headwall
32 Grooved end projecting
Vertical Ellipse Concrete
33 Square edge with headwall
34 Grooved end with headwall
35 Grooved end projecting
Pipe Arch, 18" Corner Radius, Corrugated Metal
36 90 deg headwall
37 Mitered to slope
38 Projecting
Pipe Arch, 18" Corner Radius, Corrugated Metal
39 Projecting
40 No bevels
41 33.7 deg bevels
Pipe Arch, 31" Corner Radius,Corrugated Metal
42 Projecting
43 No bevels
44 33.7 deg. bevels
Arch, Corrugated Metal
45 90 deg headwall
46 Mitered to slope
47 Thin wall projecting
Circular Culvert
48 Smooth tapered inlet throat
49 Rough tapered inlet throat
Elliptical Inlet Face
50 Tapered inlet, beveled edges
51 Tapered inlet, square edges
52 Tapered inlet, thin edge projecting
Rectangular
53 Tapered inlet throat
Rectangular Concrete
54 Side tapered, less favorable edges
55 Side tapered, more favorable edges
56 Slope tapered, less favorable edges
57 Slope tapered, more favorable edges