Suppose you know the characteristics of a gravity sewer, but you’d like to know the percent full and Froude number when it carries 20 L/s. You can dig out your old hydraulics book, look up the Manning equation, figure out how to iteratively solve it for depth, and write a little program to solve it, and after an hour or so, you may have the answer (if you didn’t make a mistake).

It’s much easier to open Bentley’s OpenFlows FlowMaster, and after about a minute, you’ll have the answer plus a lot more information.

FlowMaster 1

Now suppose you want to develop a rating curve for that pipe for a range of flows and pipe roughness. You can build an Excel spreadsheet and set up a graph, or in one minute, you can let FlowMaster do it.

FlowMaster Rating Curve

This is the kind of use case where FlowMaster can pay for itself in no time. Fast solutions with an intuitive interface are the trademark of FlowMaster.

But FlowMaster is not restricted to calculating normal depth in sewers. It can solve a wide variety of hydraulic problems. This includes a range of conduits and channels, including circular, box and elliptical pipes, and rectangular, triangular, parabolic, gutter, and most importantly, irregular channels. Think of the steps to solve for normal depth in an irregular channel. It’s only a few minutes work in FlowMaster.

FlowMaster Cross Section

And it’s not limited to uniform flow but can also perform gradually varied flow calculations.

FlowMaster GVF

Interested in other hydraulic structures like weirs, orifices, or various stormwater inlets such as grate, slotted, or curb, whether in sag or on grade. Need a rating curve for a broad crested weir? No problem. Enter the characteristics, and see the results.

FlowMaster Worksheet FlowMaster Rating Curve 2


FlowMaster is not a pipe network model for complete water and sewer networks. For those cases, you’ll need something like WaterGEMS or SewerGEMS. FlowMaster is oriented toward simple single conduits or structures. But there are a lot of them in the world.

Yes, FlowMaster is so easy to use that even your boss can use it. So, be careful, you don’t want to let your boss start using FlowMaster. It’s so much fun to use, they may not let you work on any of these kinds of problems.

Learn More About FlowMaster