Did you know that OpenRoads Designer (ORD) uses the tried-and-trusted OpenFlows technology for its hydrology and hydraulics calculations?

The OpenFlows products are a comprehensive suite of standalone software focused on hydraulic modeling of water systems including stormwater and wastewater, and have been used and trusted by engineers since the 1990’s.

Using OpenRoads Designer Drainage and Utilities (ORD-DU) makes the workflow more efficient because hydraulic analysis can be done in the same DGN environment as your 3D design. There’s no need to export or import drainage files, which saves time and avoids data loss. Keeping everything in one model also helps maintain coordination between drainage and the overall design, reducing rework and speeding up iterations. OpenRoads Designer includes a 100 inlet license of OpenFlows StormCAD’s GVF-Rational solver, for peak flow pipe and inlet design. If needed, you can activate existing licenses for OpenFlows Storm or Sewer to use more advanced solvers.

If you are concerned about results and capabilities matching other established standards such as HY-8 or FHWA Toolbox, rest assured that the OpenFlows technology has robust support for HEC-22 inlet calculations, HDS-5 culvert calculations (and more) which civil engineers have relied on for decades. Below you will find details and links to articles on some key nuances of the calculations.

Important notes:

• If content (such as a knowledgebase article) is labeled as being applicable to an OpenFlows product (such a OpenFlows Storm, StormCAD, CivilStorm and SewerGEMS), it is also applicable to OpenRoads Designer.
• There are many “gray areas” in the HEC-22 inlet standards where its documented set of formulas are not fully defined for how specific edge case situations should be calculated. So, the inlet capture calculations make accommodations for these, typically with conservative assumptions. This can however lead to differences in results compared to other software or hand calculations. The links below provide more details.

Webinar Recording: Understanding Drainage Calculations

The following webinar recording demonstrates how to avoid some common issues related to drainage calculations in OpenRoads Designer, such as culvert, inlets and uniform flow vs. gradually varied flow / backwater.

See: Answer Hour: OpenRoads Designer - Understanding Drainage Calculations

 

Understanding Important Drainage Calculation Concepts

Most hydraulics-related articles are in the OpenFlows Knowledgebase, with some information also found in the OpenRoads Knowledgebase. We also offer help within the software.

Culverts (HDS-5)

• Modeling Reference – Headwalls
• How to match culvert results with HY-8

Inlet capture (HEC-22)

• Why is it that no matter how large the inlet on grade is the gutter spread always remains the same?
• Where is the Gutter Depth measured from?
• How is the clear opening area of a grate inlet determined?
• Depth and spread calculations for grate inlet in sag
• How does the clogging factor work with catalog inlets?
• How do catalog inlets handle clogging at low depths?
• Calculation of Side Flow factor with grate width less than gutter width
• Unexpected spread and depth results for a curb inlet in sag with local depression
• Modeling gutter capture for an area inlet
• Modeling a Drainage Ditch
• Modeling Sweeper Inlets
• Modeling a curb cut
• Depth and spread calculations for "Full Capture" or "Percent Capture" Inlet Type
• Finding curb length needed to capture 100% of gutter flow in a curb inlet with depressed gutter
• Purpose of "Neglect side flow?" and "Neglect Gutter Cross Slope for Side Flow?" options
• Modeling Custom Inlets Using Inlet Capture Curves

Gradually Varied Flow (GVF) Profile Calculations

• Understanding Gradually Varied Flow Calculations in OpenRoads Designer
• StormCAD and SewerCAD (GVF Solvers) Flow Profile Calculations
• Backwater Analysis vs Capacity Analysis flow profile methods
• Why does the profile for the system appear to be at odds with the results for the capacity?
• Hydraulic grade discontinuity at steep pipes or across nodes (frontwater analysis)
• Why is the HGL reset to rim elevation for flooded structures? (StormCAD and SewerCAD solvers)
• What Happens When the Water Level Exceeds the Top Elevation of an Open Channel? - Communities
• Rational Method (Q=CIA) hand calculations different from model results

Structure Losses

• Structure Loss methods supported by each solver
• HEC-22 2nd edition energy loss calculations with the Implicit solver
• How is bend angle used in calculating losses?

Constraint-based design

• Order of constraint based design priorities for StormCAD (GVF-Rational) and SewerCAD (GVF-Convex)
• Troubleshooting Constraint Based Design Results

What’s new in OpenRoads Designer

• Visit the help document for OpenRoads Designer and click What’s New. There is a section related to Drainage and Utility enhancements.
• Review our YouTube playlists for more What’s New in the latest release.

Example Project

• OpenRoads Drainage Example – Culvert and Inlet