---
title: "Pavement Crossfalls"
canonical: "https://help.innovyze.com/space/xps/19663612/Pavement%20Crossfalls"
format: markdown
---
When runoff exceeds [inlet capacity](https://help-innovyze.atlassian.net/wiki/spaces/xps/pages/19662566/Hydraulics+Node+Data#HydraulicsNodeData-InletCapacity)**,** the spread, depth and velocity of ponded water may be calculated from the geometry and hydraulic properties of the cross section.

In an XPSWMM/XPStorm<span style="color: #333333"> </span>model, Pavement Crossfalls may be stored in the Global Database. A Pavement Crossfall record is assigned to a hydraulics inlet node using the [Inlet Capacity](https://help-innovyze.atlassian.net/wiki/spaces/xps/pages/19662566/Hydraulics+Node+Data#HydraulicsNodeData-InletCapacity) dialog.

![image](media://47da1602-b464-4e47-ac20-1b9c712691b8)

As shown in the above diagram, the Pavement Crossfalls are defined as a section extending from the boundary line (representing the edge of the drainage) to the pavement centerline. It consists of three regions:

1. **Verge** (Shoulder) region between the boundary and the gutter
2. **Gutter** channel draining to drainage inlet, lowest point designated as invert
3. **Pavement** roadway surface extending from the lip to the centerline (or highpoint)


The terms in the dialog are defined as: 

**A** Verge (Shoulder) Distance (Boundary to Back of Curb) (ft, m)

**B** Verge (Shoulder) Slope (Boundary to Back of Curb) (%)

**n-verge** Verge (Shoulder) Roughness (Manning's n)

**C** Width of Top of Back of Curb (ft, m)

**D** Distance from Face of Curb to Nominal Curb Line

**E** Distance from Nominal Curb Line to Gutter Invert (ft, m)

**F** Distance from Gutter Invert to Curb Lip (ft, m)

**G** Depth from Back of Curb to Gutter Invert (ft, m)

**H** Depth from Back of Curb to Gutter/Pavement Lip (ft, m)

**n-gutter** Gutter Roughness n

**I** Pavement Width (Lip to Road Centerline) (ft, m)

**J** Pavement Crossfall (Lip to Road Centerline) (%)

**n-pave** Pavement Roughness n