Category: Force Mains

Water is good; it benefits all things and does not compete with them.(Lao-tzu)

I saw this website on LinkedIn and was interested in the use of Chinese and Japanese characters for water.

“The present research is supported by the Japan Society for the Promotion of Sciences (JSPS). The project began its research activities on November 2014. The logo selected is quite simple but meaningful. It consists on the map of Bolivia and inside the map it is the kanji for the word Shuǐ (Chinese) or Mizu (Japanese) that means water. The kanji looks like a drop water. It was decided to use the symbol of water, as everything relates somehow to water. Water is the most vital element for life, but it can also become the most destructive force.”
“Water is good; it benefits all things and does not compete with them.” (Lao-tzu)

How to Make a Break Node in SWMM5 and InfoSWMM for Force Mains

The key problem discussed here is to keep the Force Mains full or d/D equal to 1 when the pumps turn on, it is sometimes difficult to get it to work like ICM or IWCS due to the fact that there is only one Q in the link of the SWMM 5 solution compared to the 4 or more flow points in the IWCS solution. I have suggested in past that the user add a break node in the force main at the end so that the downstream end of the Force Main is full – however does not always work if there is a gravity main at the end of the rising force main. The gravity main takes all of the flow coming down the long force main and the downstream node depth stays small so the Force Main is never full – this annoys the customers. My suggestion is to increase the gravity main roughness to simulate the effect of the force main transitioning to the gravity main – this keeps the depth higher and the force main full most of the time and full when the pump turns on.

Runoff from One Watershed for a 100 Year Simulation with SWMM 5 Statistics for Peak, Mean and Total Runoff

Introduction:  This set of blogs uses the 1000 year rainfall/runoff/hydraulics model that you can download at to show the inner workings of SWMM 5 and by extension InfoSWMM and H2oMap SWMM […]

How to use the Report Feature of the HGL Plot in InfoSWMM

Subject:   How to use the Report Feature of the HGL Plot in InfoSWMM   The report feature of the HGL plot helps you understand in more detail the pump flows, forcemain flows and node heads.   Step 1. Load the Domain in the HGL Plot using Report Manager     Step 2. Click on the Report Command to Show […]

The Non Linear Term in the Saint Venant Equation of SWMM 5

Subject: Non Linear Term in the Saint Venant Equation of SWMM 5 The flow equation has six components that have to be in balance at each time step: 1. The unsteady flow term or dQ/dt 2. The friction loss term (normally based on Manning's equation except for full force mains), 3. The bed slope term or dz/dx […]

How is the St Venant Equation Solved for in the Dynamic Wave Solution of SWMM 5?

Subject:   How is the St Venant Equation Solved for in the Dynamic Wave Solution of SWMM 5?   An explanation of the four St. Venant Terms in SWMM 5 and how they change for Gravity Mains and Force Mains. The HGL is the water surface elevation in the upstream and […]

Output Statstics Manager to find negative flows in InfoSWMM

ubject:  Output Statstics Manager to find negative flows in InfoSWMM   Output Statstics Manager to find negative flows with these parameters:   1.       Pipe Features 2.       Use a Domain with your force mains 3.       Select Flow 4.       Event Dependent 5.       Total – NOT Mean or Peak to  find the negative and positive flows 6.       Large NEGATIVE Flow Threshold 7.       Large NEGATIVE Volume Threshold 8.       Zero […]

Comparison of the H2OMAP SWMM5 Hazen Williams Force Main Solution to a HW Solution

Note:  Comparison of the H2OMAP SWMM Hazen Williams Force Main Solution to a HW Solution   In this example, we compare the force main head loss in four links in H20Map SWMM to the head loss in a steady state HazenWilliams solution for the same length pipe, diameter and flow (Figure 1).  The H2OMap SWMM model has a […]

Innovyze Releases QualWatch, Next Generation of Early Warning Network Monitoring and Water Quality Event Detection

Press Room | Products | News | Events | The Company   Innovyze Releases QualWatch, Next Generation of Early Warning Network Monitoring and Water Quality Event Detection Breakthrough Release with Vanguard Predictive Analytics Delivers 24/7/365 Distribution System Water Quality Surveillance, […]