---
title: "HEC-12 and HEC-22"
canonical: "https://help.innovyze.com/space/xps/19663628/HEC-12%20and%20HEC-22"
format: markdown
---
**A separate addendum** consisting of the complete FHWA documentation for HEC-12 "Design of Highway Pavements" is provided as part of the documentation for user training courses. Contact your account representative for additional information.

![image](media://09a91e1e-e285-4f88-b0e5-6fa0bbef812c)

This implementation of HEC-12 supports:

- **[Grated Inlets](https://help-innovyze.atlassian.net/wiki/spaces/xps/pages/19662566/Hydraulics+Node+Data#HydraulicsNodeData-HEC12GratedInlet)**
- **[Curb Inlets](https://help-innovyze.atlassian.net/wiki/spaces/xps/pages/19662566/Hydraulics+Node+Data#HydraulicsNodeData-HEC12CurbInlet)**
- **[Slotted Inlets](https://help-innovyze.atlassian.net/wiki/spaces/xps/pages/19662566/Hydraulics+Node+Data#HydraulicsNodeData-HEC12SlottedInlet)**
- **[Combinations of grate and curb inlets](https://help-innovyze.atlassian.net/wiki/spaces/xps/pages/19662566/Hydraulics+Node+Data#HydraulicsNodeData-HEC12CombinationGrateandCurb)**

### **Gutter Depression**

The capture efficiency of an inlet can be increased by having a locally depressed gutter section (inches, mm).

The inlets may be located on either continuous grades or in sumps.