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Area of each unit - Modelling rain barrels in SWMM 5

Does the 'area of each unit' when modelling rain barrels in SWMM represent the area of the impervious area contributing run-off into the rain barrel (for example the roof area) or the cross sectional area of the rain barrel itself? SWMM user manual a

Pollutant accumulation plot

Is it possible to create a plot or a result table containing the current load of pollutants on the catchment for long series simulation?

External Input File for SWMM

I have 8 subcatchments in a watershed and all these 8 subcatchments have 8 different curve number values(infiltration model).I want to vary the curve number values and look at the change in the associated hydrograph. Can you kindly suggest me in whic

Excessive Continuity Errors in node (SWMM5)

Hi, I am trying to model an infiltration pond in SWMM and get excessive (90%+) continuity errors for the pond node.  The overall flow routing continuity error is zero for the site.  The pond is set up to have a high flow bypass for a continuous model

How to Calibrate EPA-SWMM Model with PEST?

Can anyone help me providing a sample SWMM model calibration tutorial set that uses PEST. I have a storm network model and I need to calibrate the model using PEST. 

Any relevant suggestion, tutorial or reference is appreciated in advance.

SWMM rain-garden - accounting for exfiltration

Hi there users,

Having some trouble modelling rain-gardens in SWMM. I have a few rain-gardens draining impervious surfaces in an urban catchment. 

In checking the detailed rain-garden flux files, it would appear that there is no exfiltration and the so

Problems with SSA version of SWMM computing peak inlet flows

I am using Autodesk SSA version of SWMM.  I am getting unreasonable results that are too high when the inlet is completely submerged by a flow that is say 5 times the inlet capacity.  The program appears to calculate the flow in the upstream link bas

Baseline/sanitary flow variation outside of typical parameters

Hello!

I am working on a SWMM 5 continuous model.  I have a sanitary DWF that varies every three days due to an industrial discharge, so none of the pre-set flow variation patterns (hourly, daily, monthly)  will vary the flow appropriately.  Is there

LID area and impervious runoff calculations

Hi users,

Just a query regarding LID's in SWMM. Let's say that impervious sub-catchmant A has a total area of 100 m2. 

Let's say that I deploy a LID into sub-catchment A (a rain barrel) and set its surface area as 10 m2 (thus it occupies 10% of sub

Storage Unit, No Volume Change

Pollutant removal (treatment) - Setting a constant concentration as the result of the treatment expression

Hello there,

I am trying to set a constant outflow concentration as the result for a treatment-equation, i.e. BOD: C=50.
Unfortunately, setting a constant value for the concentration does not work, the result of the effluent concentration would be just

Having issues with a storage basin drain down simulation

Hi,

I'm having issues with an  attenuation feature. I've simulated the rainfall event (24 hours) and now I'm looking to see how long it will take to drain down using outlets with Head/flow relationships (simulated vortex controls e.g hydrobrake). Prob

Accuracy of EPA SWMM to model pressure flow?

I would like to model a distribution network of drinking water with EPA SWMM. Therefore, the flows will be pressurized. Is it valid to theoretically model such flows EPASWMM instead of using EPANET?

Pump Curve Behavior

I am new to trying to model VFD Pumps. I have a single pump running on a single type 3 curve without controls besides on-off levels. Looking at the pump operation curve, the purple diamond indicates that the pump is operating on the curve most of the

Ave head loss in links(pipes)

i have been using SWMM 5.1 for stormwater catchment modelling. i am wondering whether f L/D  should be inputted to include head loss in pipe length as a average head loss.where f is the friction factor depending on pipe relative roughness and Reynold

Pond design in SWMM

Dear Bob

I am trying to design a pond in SWMM where I want to maintain atleast 1m depth of water before allowing the discharge from the pond. For this I have given 1m initial depth of water in the pond and kept its height as 2.5 m, but while simulatin

Antecedent dry days for a single event and in a continuous simulation

Hi, i hope someone can help me about this misunderstanding:  considering a single precipitation event, i can not undestrand if i have to insert, as imput, the "initial build up" or the "antecedent dry days", or both of them. I guess i have to set onl

Which Computer power (CPU) is adequater for long term modelling?

If a distributed SWMM model is used to model a decade(s) long timeseries including water quality on a Windows 7 OS, which computer power is necessary? 2.7 GHz?, 3.4 GHz? How many cores? CPU or GPU? Please share your experiences? Especially if Monteca

Piezometric Head of the Nodes in SWMM 5.

How do I get the piezometric head ( pressure + elevation head) of the nodes in the result of SWMM 5? Is there options for this or something has to be implemented in the source code of SWMM5 ?  Please throw some light in this regard.

Pressurized nodes in EPA SWMM

Hello everybody!

I'll like to know if is it possible to prevent flooding in nodes (no storage nodes). The problem happens when I close R-1 and R-2 completely, because C-11 reaches its maximum capacity and then N-1 begins to flood. I would like that th