Pre 2014 Blogs

All Posts (522)

Calculate runoff depth of a subbasin

Hi all,

I am trying to calculate runoff depth for a subbasin from the subbasin peak flow ( collected from SWMM model)by inverting the manning's equation ( as SWMM uses manning's equation for the calculation of peak flow) . In that case, what should be the slope value? For example if the slope of that subbasin is 5%, should I give 5 in the manning's equation or 0.05? Thanks.

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SWMM 5 Water Quality Example Files

SWMM 5 Water Quality Example Files

File Name Description
RUNOFF20_SW5.INP Runoff Example # 20 - PCSWMM 3.2 EXERCISE 5
RUNOFF23_SW5.INP A wide parabolic channel between 301 and 401
RUNOFF31_SW5.INP PCSWMM 3.2 EXERCISE 5 - Runoff example 31
RUNOFF41_SW5.INP Runoff example 41 - Input of constant groundwater quality
RUNOFF42_SW5.INP Precipitation quality only

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Modeling "Leaf" Gates

I am trying to determine the best way to represent "leaf" gates in SWMM5.  The gate consists of two panels that overlap each other.  The top gate serves as an overflow weir and drops as the upstream water level rises.  If the top gate is fully lowered and the upstream water level is still rising, then both gates would be lifted up to create an underflow outlet.  This would then eliminate the overflow aspect.


My thought is to model two separate gates.  The overflow gate would need some kind of timeseries to control (lower) the crest elevation of the overflow gates until the upstream water surface elevation exceeds level X.  At that time, the overflow gate would close and flow goes to zero.


A separate underflow gate would open to full capacity if the upstream water surface elevation exceeds level X.


I welcome your suggestions on how best to tackle this issue.  Thanks.

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Diversion Sturctures and SSO events in SWMM 5

I'm a new user to SWMM and i'm currently trying to model SSO events at a waste water treatment plant. I've been using dynamic routing and I've been having trouble modeling the diversion structure. Currently I have a storage node acting as a wet well that feeds a type 3 pump. The pump is connected to an orifice which regulates the the pump to 4.0 MGD (anything over that would risk washing out the plant). Also coming out of the wet well i have a weir that is offset from the invert elevation of the storage tank. After some adjusting of that elevation I am able to match the volume of diverted flow for specific events. The problem comes in that very small adjustments of that height (as little as 0.5%) has a major impact of the simulated volume (around 50%) which makes the model impossible to calibrate and useless for a design event. Does anyone have any suggestions on how better model the diversion structure? Any help would be appreciated.

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Innovyze Press Release

 Insider BlogLinkedInTwitterYouTubeYouTube

Innovyze Launches Educational Product Webinar Series

Beginning in September Innovyze is offering free educational webinars.  The 14 part technical series runs through March 2014.  Users and prospective users of Innovyze software can register for one or all of the events.
Each webinar will last approximately one hour and is hosted live by an Innovyze engineer and will include:
  • Technical Overview
  • Product Features and Benefits
  • Live Product Demonstration
  • Questions and Answers

Webinar Schedule:

Risk-based Prioritization of Sewer Rehabilitation with InfoMaster Sewer
September 9, 2013
With InfoMaster Sewer, wastewater utilities and their consultants can leverage both their existing CCTV information and GIS data to create an optimized prioritized renewal/rehabilitation plan. Users can choose whether to weight their plan towards current conditions or towards a calculated risk (probability and consequence of asset failure and business risk exposure). NASSCO PACP, MACP and LACP V6.0 certified,InfoMaster Sewer also includes the ability to custom-built a multi-step decision tree of rehabilitation techniques based on current pipe condition and hydraulic capacity. The software provides a sound foundation to budgeting for proactive infrastructure renewal/rehabilitation work and responding to public inquiries about renewal schedules and priorities. Available exclusively for the Esri ArcGIS 10.x platform, InfoMaster Sewer includes components to run on desktop, web, tablet, and smartphone environments.
Real Time Water Distribution Forecasting and Modeling with IWLive
September 23, 2013
IWLive is the first product of its kind to combine hydraulic modeling, weather predictions, and current SCADA information to give water system operators a clear picture of how their system will behave in the future. IWLivecan be used to propose fixes to operational problems before they occur; common examples include: water main breaks, peak demand periods, real time fire flow evaluation.
Real Time Analysis of System Demands with DemandWatch and Demand Analyst
October 14, 2013
Short-term water demand pattern forecast is essential for cost-effective operation of distribution systems. A revolutionary short-term demand forecasting software, DemandWatch changes the way water utilities around the world leverage historical demand data to estimate future water demands for real-time, near-optimal control and management of their water distribution systems. Its primary strength lies in its adaptive demand forecasting process, which can continually update and refine estimated demand values in real time. Armed with this power, water utilities can better plan, operate and manage their water distribution systems, improve conservation measures, minimize energy consumption, meet regulatory compliance, and enhance customer service.
Using BalanceNet for Real Time Optimization and Energy Savings of Water Distribution Systems
November 4, 2013
Energy costs can constitute a largest expenditure for nearly all water utilities — consuming as much as 65 percent of an annual operating budget. BalanceNet is designed expressly to assist water distribution system operators and train new operators in managing their energy consumption more effectively by equipping control rooms with the real-time ability to develop sound, cost-effective pump scheduling policies that reduce operational costs. Designed for online applications with existing SCADA systems, BalanceNet reads real-time field data, instantly updates the network model and determines the pump and treatment plant operation schedules that will yield the lowest operating cost while satisfying the system’s hydraulic and water quality requirements. It uniquely combines an optimized mass balance model with an advanced network solver to quickly produce a set of near-optimal solutions for improving system operations.
Real-Time Surveillance of Water Distribution Systems with PressureWatch: Identifying and Managing Leaks and Breaks
November 18, 2013
PressureWatch provides water utilities the unprecedented ability to continuously monitor and assess their network hydraulic performance so that problems can be resolved quickly or avoided altogether. The software provides for rapid identification and warning of network performance problems, leaks, breaks, loss of system integrity, and other operational inefficiencies, and helps minimize their impact through early detection and location. It allows utilities to manage their water networks in a more effective and highly proactive way.
Real-Time Water Quality Monitoring and Compliance with QualWatch
Dec 2, 2013
QualWatch provides water utilities continuous real-time monitoring of water quality dynamics in their water distribution networks to help them quickly detect potential contamination and prevent security breaches. It enables water utility operators to instantly compare water quality data against regulatory requirements such as maximum contaminant levels and pinpoint any violations; recognize abnormal water quality changes caused by contamination; detect unanticipated normal events such as main breaks, backflows and sensor malfunctions; and spot the onset of anomalous incidents they can evaluate and act on. The result is proactive network water quality management that ensures safety and security for all consumers. QualWatch can analyze any standard water quality data — total chlorine, free chlorine, chloride, pH, electrical conductivity, total organic carbon, turbidity, total dissolved solids, nitrate, chlorophyll, oxidation reduction potential and other parameters — and help detect a wide variety of contaminants including pathogens, metals and pesticides.
Risk-based Prioritization of Water Main Replacement featuring InfoMaster Water
December 16, 2013
As the rapid deterioration of underground infrastructures progresses, many water utilities are struggling to develop a rehabilitation and replacement program that addresses the most critical pipes in the system. Many capital improvement programs spend millions of dollars annually on projects that do little to lower total system risk. You'll learn how InfoMaster Water lets utilities leverage GIS, hydraulic modeling, work order management and other enterprise data to analyze the likelihood and consequence of pipe failure in a water network — and use this information to develop optimized risk-based infrastructure improvement plans. Available exclusively for the Esri ArcGIS 10.x platform, InfoMaster Water includes components to run on desktop, web, tablet, and smartphone environments.
Modeling and Eliminating Transients in Water Distribution Systems with InfoSurge
January 6, 2014Transients in water distribution systems are a major concern for pipeline analysis, design and operation as they have the potential to wreck or damage pipeline systems and equipment, reduce system efficiency, induce adverse water quality conditions, and threaten the integrity and quality of supply as well as public safety. Learn how to use InfoSurge to affectively diagnose and solve distribution system transient issues.
Advanced Integrated Catchment Modeling with InfoWorks ICM
January 21, 2014
Explore InfoWorks ICM, the first software in the world to successfully combine 1D simulation of flows in sewers with 2D simulation of surface flooding. It can be effectively used to accurately simulate the flow of stormwater and wastewater; predict flood risks; support cost-effective drainage design and management; develop online urban flooding forecasts; conceive and evaluate sound and reliable urban catchment strategies such as storm sewer separation, active real-time control and provision of adequate additional storage; and improve the operation of any drainage system.
Real-Time Modeling and Operational Forecasting of Sewers with ICMLive
February 3, 2014
ICMLive provides sewer system operators and engineers with ability to continuously monitor and effectively control the flow of stormwater and wastewater in their collection systems. A powerful risk assessment and real-time decision making tool, ICMLive combines the comprehensive integrated catchment modeling capabilities ofInfoWorks ICM with sophisticated real-time operational forecasting, early warning, and emergency management. It enables managers and operators to consider the influence of a full range of catchment factors in the management of flooding and the reduction of unregulated discharges; the optimization of storage and existing infrastructure, leading to savings on capital works; and the optimization of pumps to lower energy costs and reduce CO2 emissions.
Modeling and Control of Surface Flooding with InfoSWMM 2D
February 17, 2014
Two-dimensional (2D) simulation is better suited than one-dimensional simulation (1D) for modeling flows through complex geometries. These include urban streets and buildings, road intersections and other transport infrastructure, and open ground, where either the source or direction of flow is problematic to assume. In this seminar, you'll learn how to use InfoSWMM 2D to perform a 2D overland flow analysis to better manage flooding and improve drainage and water quality. The software can be effectively used for many types of optimization studies like Green and Grey infrastructure including conveyance, storage and treatment as well as for sewer rehabilitation, conveyance, storage and treatment.
Designing and Implementing an Effective Unidirectional Flushing Program in Record time with InfoWater UDF
March 3, 2014
Unidirectional flushing (UDF) is the most effective way of cleaning water mains and maintaining water quality and system capacity. It also requires the least amount of water of any cleaning method. Valves are closed and hydrants opened to create a one-way flow that accelerates the speed of water in the mains, maximizing shear velocity near the pipe wall and producing a scouring action that effectively removes sediment deposits and biofilm. Learn how the automated design tools in InfoWater UDF, allow engineers to create these flushing sequences in record time.
Real-Time SWMM-based Modeling and Operational Forecasting of Sewers with SWMMLive
March 17, 2014
SWMMLive provides sewer system operators and engineers with ability to continuously monitor and effectively control the flow of stormwater and wastewater in their collection systems using the USEPA SWMM engine. A powerful risk assessment and real-time decision making tool, SWMMLive combines the modeling capabilities ofInfoSWMM with sophisticated real-time operational forecasting, early warning, and emergency management. It enables managers and operators to consider the influence of a full range of catchment factors in the management of flooding and the reduction of unregulated discharges; the optimization of storage and existing infrastructure, leading to savings on capital works; and the optimization of pumps to lower energy costs and reduce CO2 emissions.
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Running SWMM5 Using .bat files

Hi Robert,

I have a folder with many inp files representing different urbanization scenarios for a watershed in VA. I would like to automate the processing of this files because it is something I'll most probably will have to do again. From my research it looks like something that can be done through .bat files but I have no idea how it would work. maybe there is a reference you can share or you have addressed this issue in previous blogs.

Thank you for all your help!


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Large data output extraction in SWMM


I have developed a model with 33 subcatchments using 1 year hourly  rainfall data. The problem is when I try to get the runoff for all the subcatchments it says '' too many objects to display".

It would be really helpful If you could tell me how can I get the runoff from all the 33 subcatchments together?


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i have every 1h of total 12h rainfall time series data and run for 12h . so i got total precipitation in status report is 108 mm but when i sum up total time series is 112mm which is grater then report.

moreover when i use design strom for every 10 minute of 2h this value is shown 11.38mm but the sum up of time series data is 86mm.

i am really confuse, please any one help me for how to calculate total precipitation in status report.

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thanks bob for your reply, can you tell me another issues like total precipitation in status report how it is calculated? i am using time series rainfall for 10 minute interval as intensity. total precipitation value and depth in status are not clear to me.

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flood Volume in canal system

hi, how to calculate the volume spilled from
the Khals in SWMM 5.0?
can anyone help on this issue?
In Status report of SWMM, final storage volume is shown after simulation. is this value  my required value? please help on this issues.

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Dear All,

I am trying to update an I&I report done by a consultancy using SWMM5 modelling.  

The sewer flow gauged seems to be difficult to be used in SWMM model, because we only gauge flow data including upstream flows. In SWMM, we could only assign junctions with net ADWF for any subcatchments,  I was trying to lag upstream and downstream flows and get net inflow from subtraction of two series of data. However, there is no proper lag time as sewer travel time changes with flow and my flow data for downstream have so many minus value.

If you have any suggestion on this NET inflow thing, please help.

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Groundwater Calculations in SWMM

Hello Robert !

I am trying to incorporate groundwater in my model. Right now it is showing high negative groundwater error. Is the groundwater error calculated same as the continuity error ?

The Percent Error = 100.0 * (1.0 - totalOutflow / totalInflow)

What are the components and corresponding equations for inflow and outflow for groundwater ?I think the outflow is calculated as

QGW = A1(HGW - H*)B1 - A2(HSW - H*)B2 + A3(HGW HSW)

But how is the inflow calculated ? There are quite a few parameters used in aquifer data editor and groundwater data editor ( i.e. Conductivity slope, tension slope etc) I want to learn them in details. Can you suggest me any documentation for them?

I am following some of the regional modeling attempts for parameters who used XP-SWMM. And they used a lot of parameters like

' Fraction of evapo-transpiration assigned to upper zone, Maximum depth of significant
lower zone storage, Curve fitting parameter, Initial upper zone moisture , Coefficient for unquantified losses
Average slope of the tension versus soil moisture curve. '

It would be very helpful if I could  use this data in my SWMM model. Are they  denoted differently in SWMM? Please help.



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Time series Stage input

I have some confusions in using stage time series. Please help.


There is an option of using time series data for outfall stage. Should I include elevation of water or depth of water in this case.


For example,

invert EI =-5 ft

Outlet offset= 0

depth of conduit = 12 ft

depth of water ( stage)  =7 ft


Now, should I  input  stage at outlet = 7ft

or I should input with reference to Invert EI= 7-5= 2ft


I have the same confusion for initial depth of water in junctions. Is it just depth (7ft) or the elevation (2ft)




Thanking you  in anticipation.




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I am modeling a natural channel with gated spillway. There are two gates as shown in the following figure.

I want to use two different time series for the two gates. How do I model the two gates in SWMM and use time series control rules simultaneously? If I use two different orifice for two gates then wont they superpose on one another? I want to model them to act parallel as shown in the figure and add two different time series for the two gates.

Please help.

Kindest regards,


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I am trying to model the interaction between stormwater and surface water using SWMM. Flow in the canal I am dealing with is maintained by gated spillways. The canal has very irregular and even  adverse slope i.e. slope against the direction of the flow as shown in the following figure.

If I provide the SWMM model with this exact canal profile against the direction of flow, will it be able to reflect the head loss due to friction and change in conveyance due to adverse slope? ( I am providing the gated spillway upstream to input the necessary head)

What alternative can I use to represent the effect of this adverse slope in a simplified way?

This is stressing the scope of SWMM I understand, but if I can do this,  this will be something very interesting .

I appreciate your help as always. Thanking you in anticipation.



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I am modelling a natural channel with a gated spillway. I am using the rectangular orifice option to install the gate .

In SWMM, orifice is added as a link between two nodes and according to the manual "located either at the bottom or along the side of the upstream node."

My question is does SWMM use the geometry ( depth + width) of the orifice to consider it as an usual  conduit for the flow from upstream node to downstram node as it is connected between two junctions  just like the conduis?

or Its just a gate acting at the upstream node though added as a link?

Thanking you in anticipation.


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Transect data processing in SWMM


My model includes a canal and I am using a transect to represent the canal. One of the typical sections is shown in the  figure. I uses the actual elevation data for the transect cross section and hence some coordinate values are negative.

1. The profile view does not show the negative portion. Is there any way I can see the full depth profile view? will there be any problem in SWMM internal calculation if I use negative value ( as shown in the figure).

2. From the transect sections, does SWMM automatically calculate the slope ( using the lowest coordinates) or it uses the section only to calculate area and wetted perimeter. I am asking this because if it considers lowest coordinates than there will be problem from double counting if I input slope through offsets.

3. I will use stage data at outfall. what is the datum SWMM considers for stage data depths given?

Thank you in anticipation.



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Modeling bridge with obstruction.

I am modeling a natural channel which has a bridge with two piers in it obstructing the flow. The upstream section  is shown in the image below.

Since I have the coordinates I can add the cross section as a transect in SWMM as I have tried below

I have also added the appropriate conduit code.

1. Will this work?

2. What alternative do I have?

As an alternative I am adding this three sections as three separate links. ( repost from the comment as the images in comment are not clear enough). Please let me know if this is what you suggested.

Kindest regards,


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