SWMM4 Conversion Notes

This topic discusses how InfoWorks ICM converts existing SWMM4 network components into an InfoWorks ICM network and InfoWorks ICM network objects. Some data is not imported at all, or is only partially imported. Some SWMM4 objects are imported as more complex InfoWorks ICM objects, and additional data will be required to completely define these InfoWorks ICM objects.

The importer supports the following:

RUNOFF and EXTRAN blocks in the SWMM4 data files
Asset data only. Event data (e.g. rainfall, inflow hydrographs, etc.) is not imported.
SWMM4 EPA release v4.31
SWMM4 v4.4h (partial support only)

SWMM4 RUNOFF BLOCK

The RUNOFF block generates surface and subsurface runoff based on rainfall hyetographs.

The importer supports asset data only. Event data is not imported.

The following data groups are not supported by the conversion process:

B0, B1, B3: Simulation and Printing Parameters
C1 - C5: Snowmelt data - InfoWorks ICM runoff model does not have an equivalent to SWMM4 snowmelt
D1, E1 - E3: Rainfall data - Event Data
F1: Evaporation data - Event Data
G1, G2: Channel/pipe data - The importer assumes that the user will define the conduit network in the EXTRAN block.
H2 - H4: Groundwater subcatchment data - InfoWorks ICM groundwater model is not directly equivalent to the SWMM4 groundwater model.
I1 - I3: Snowmelt data - InfoWorks ICM runoff model does not have an equivalent to SWMM4 snowmelt
J1 - J4, K1, L1: Washoff data - InfoWorks ICM washoff model is not directly equivalent to the SWMM4 washoff model
M1 - M3: Print control data - Event Data

The following sections describe the SWMM4 variables that are read by the importer and the InfoWorks ICM fields the data is imported into. Details of any conversions or defaults assumed are also listed.

Data Group A1 - Run Identification

The Run Identification typically describes the system and storm being simulated.

The importer adds the Run Identification text to the Description Page of the Network Properties Dialog.

Data Group B2, B4 - Run Control

Data Group B2

The importer reads the following fields:

SWMM4	Description
METRIC	Units Information 0 = US Customary Units 1 = Metric
INFILM	Runoff Volume Model Type 0 = Horton Equation 1 = Green-Ampt Equation

SWMM4

Description

METRIC

Units Information

0 = US Customary Units

1 = Metric

INFILM

Runoff Volume Model Type

0 = Horton Equation

1 = Green-Ampt Equation

Data Group B4

This is an optional data group. The importer reads the following fields:

SWMM4	Description
PCTZER	Percentage of impervious area with no depression storage Default value = 25 Used to calculate Subcatchment Surface Areas.
REGEN	Determines regeneration rate for Horton infiltration Default value = 0.01

SWMM4

Description

PCTZER

Percentage of impervious area with no depression storage

Default value = 25

Used to calculate Subcatchment Surface Areas.

REGEN

Determines regeneration rate for Horton infiltration

Default value = 0.01

The SWMM4 REGEN variable is used to calculate the InfoWorks ICM Horton Decay value.

Horton Recovery = REGEN x Horton Decay

Where:

REGEN = regeneration rate for Horton Infiltration (SWMM4 Data Group H1)

Horton Decay = WW(11) variable (SWMM4 Data Group H1)

Data Group H1 - Subcatchments

Data in Data Group H1 is imported into the Subcatchments table.

Each subcatchment has three surfaces to represent it:

Impervious surface with depression storage
Impervious surface with no depression storage
Pervious surface

The importer creates a Runoff Surface for each unique set of runoff characteristics. A Land Use is created for each unique set of runoff surfaces.

All surfaces use Routing Model type SWMM.

Impervious surfaces use Runoff Volume Type Fixed with Fixed Runoff Coefficient of 1.0.

SWMM4

Description

InfoWorks ICM Data Field

Hyetograph Number

Rainfall Profile

NAMEW

NAMEW	Description
>0	Sucatchment number
-1	Ratio Option
-2	Default Option

NAMEW	Description
>0	Subcatchment ID
-1	See Ratio Option below
-2	See Default Option below

NGTO

Channel/pipe or inlet (manhole) number for drainage

Node ID

WW(1)

Subcatchment Width

Dimension

WW(2)

Subcatchment Area

Total Area

WW(3)

Percentage of impervious area

WW(3) is used to calculate the Runoff Surface Areas

See Subcatchment Surface Areas below

WW(4)

Ground Slope

Slope

WW(5)

Impervious area Manning's roughness

Runoff Routing Value

(Surface Type = Impervious

Runoff Volume Type = Abs)

WW(6)

Pervious area Manning's roughness

Runoff Routing Value

(Surface Type = Pervious

Runoff Volume Type = Abs)

WW(7)

Impervious area depression storage

Initial Loss Value (metres)

(Surface Type = Impervious

Initial Loss Type = Abs)

WW(8)

Pervious area depression storage

Initial Loss Value (meters)

(Surface Type = Pervious

Initial Loss Type = Abs)

WW(9)

Parameter depends on runoff volume model being used (specified in Data Group B2)

Equation	SWMM4 Variable Description
Horton	Maximum initial infiltration rate
Green-Ampt	Average capillary suction of water

InfoWorks ICM Data Field in Runoff Surface table depends on runoff volume model being used

Runoff Volume Type	InfoWorks ICM Data Field
Horton	Initial infiltration
GreenAmpt	Green Ampt Suction

WW(10)

Parameter depends on runoff volume model being used (specified in Data Group B2)

Equation	SWMM4 Variable Description
Horton	Minimum infiltration rate
Green-Ampt	Saturated hydraulic conductivity of soil

InfoWorks ICM Data Field in Runoff Surface table depends on runoff volume model being used

Runoff Volume Type	InfoWorks ICM Data Field
Horton	Limiting infiltration
GreenAmpt	Green Ampt Conductivity

WW(11)

Parameter depends on runoff volume model being used (specified in Data Group B2)

Equation	SWMM4 Variable Description
Horton	Decay rate of infiltration
Green-Ampt	Initial moisture deficit for soil, volume air/volume voids ratio

InfoWorks ICM Data Field in Runoff Surface table depends on runoff volume model being used

Runoff Volume Type	InfoWorks ICM Data Field
Horton	Decay factor (converted from l/s to l/hr)
GreenAmpt	Green Ampt Deficit

Subcatchment Surface Areas

Each subcatchment is represented by three surfaces. The areas of these surfaces are calculated as follows:

Runoff Area 1 = WW(3) x (100 - PCTZER)/100

(1)

Runoff Area 2 = WW(3) x PCTZER/100

(2)

Runoff Area 3 = 100 - WW(3)

(3)

Where:

WW(3) = Percentage of impervious area (Data Group H1)

PCTZER = Percentage of impervious area that has no depression storage (optional Data Group B4)

If Data Group B4 has not been included in the data file, a default value of 25 is assumed for PCTZER.

Ratio Option

Ratio values for subcatchment parameters can be set in Data Group H1. If NAMEW (Subcatchment ID) is equal to -1, the non-zero subcatchment parameter values on this line will become multiplying factors for entries of subsequent subcatchment parameters. The ratio values will apply until they are redefined.

Default Option

Default values for subcatchment parameters can be set in Data Group H1. If NAMEW (Subcatchment ID) is equal to -2, the non-zero subcatchment parameter values on this line will become the default values for entries of subsequent subcatchment parameters. The default values will apply until they are redefined.

SWMM4 EXTRAN Block

The EXTRAN block routes flow through the drainage system.

The importer supports asset data only. Event data is not imported.

The following data groups contain event data and are therefore not supported by the conversion process:

B0 - B1, B3 - B8: Simulation and printing parameters
F2: Time varying orifice setting data
J1 - J4: Boundary conditions
K1 - K3: Hydrograph data

The following sections describe how InfoWorks ICM converts SWMM4 data in the EXTRAN block into InfoWorks ICM network objects.

Data Group A1 - Run Identification

The Run Identification typically describes the system and storm being simulated.

The importer adds the Run Identification text to the Description Page of the Network Properties Dialog.

Data Group B2, BA, BB - Run Control

Data Group B2

The importer reads the following fields:

SWMM4	Description
METRIC	Units Information 0 = US Customary Units 1 = Metric
AMEN	Default plan area for all manholes 0 = default manhole diameter of 4ft (1.22m)

SWMM4

Description

METRIC

Units Information

0 = US Customary Units

1 = Metric

AMEN

Default plan area for all manholes

0 = default manhole diameter of 4ft (1.22m)

Data Group BA

The importer reads one variable from Data Group BA:

SWMM4

Description

IWLEN

Irregular section conduit lengths are entered at two locations in the SWMM4 file: at the C1 and C3 lines.

The variable IWLEN controls which of these two lengths should be used.

IWLEN

Conduit length

Length specified on C1 line and C3 line must be equal or error occurs.

(Length specified on C3 line will be imported into InfoWorks ICM)

Length specified on C3 line

Length specified on C1 line

Data Group BB

Data Group BB is optional.

The importer reads the following fields:

SWMM4

Description

JELEV

The value of JELEV determines the interpretation of depths.

The table below lists the parameters interpreted as absolute elevations for values of JELEV.

JELEV	Variables interpreted as absolute elevations
0	None (Default Value)
1	Conduit ZP values (C1)
2	Conduit ZP values (C1) Junction Initial Depth (D1)
3	Conduit ZP values (C1) Junction Initial Depth (D1) Surface area/elevation data (E2)
4	Absolute elevations used throughout including: Conduit ZP values (C1) Junction Initial Depth (D1) Surface area/elevation (E2) Orifice ZP (F1) Weir YCREST and YTOP (G1) Pump Station control depths (H1)

IPRATE

The value of IPRATE determines the manner in which pump curves are handled.

IPRATE	Pump curve Handling
1	Default. Uses three PRATE/VRATE pairs for pump inputs
2	Uses number of PRATE/VRATE pairs

See Data Group H1 for more details on pumps.

Data Group C1 Conduit Data

The importer reads the following fields:

SWMM4

Description

InfoWorks ICM Data Field

NCOND

Conduit ID

Asset ID

NJUNC(1)

Upstream Junction ID

US Node ID

NJUNC(2)

Downstream Junction ID

DS Node ID

Initial Flow Values

User Number 1

(Initial flow does not need to be set as InfoWorks ICM automatically carries out initialisation)

NKLASS

Conduit Shape

ID	Shape
1	Circular
2	Rectangular
3	Horseshoe
4	Egg
5	Baskethandle
6	Trapezoidal Channel
7	Parabolic/Power Function Channel
8	Irregular (natural) channel

A negative NKLASS creates a flap gate that will only let water move from the downstream node to the upstream node. See Flap Gate Conversion below.

Shape ID

For detailed information see Shape (NKLASS) Conversionbelow

AFULL

Cross Sectional Area of conduit

DEEP

Vertical depth of conduit (diameter of circular conduit)

Height

WIDE

Maximum width of conduit

Bottom width of trapezoid

Top width for parabolic

Not required for conduit type NKLASS =1 or 8

Width

LEN

Conduit Length

A negative LEN creates a flap gate that will only let water move from the upstream to the downstream node. See Flap Gate Conversionbelow.

Length

ZP1

Distance of upstream conduit invert above junction invert.

If optional Data Group BB is included in the SWMM4 data file, the interpretation of ZP1 is dependent on the value of JELEV.

JELEV	Description
0	Distance of upstream conduit invert above junction invert
>0	Absolute elevation of upstream conduit invert

US Invert Level = ZP1 + Z

Where Z is node invert elevation (from Data Group D1)

If optional Data Group BB is included in the SWMM4 datafile:

JELEV	Upstream Invert Level
0	ZP1 + Z
>0	ZP1

ZP2

Distance of downstream conduit invert above junction invert.

If optional Data Group BB is included in the SWMM4 data file, the interpretation of ZP2 is dependent on the value of JELEV.

JELEV	Description
0	Distance of downstream conduit invert above junction invert
>0	Absolute elevation of downstream conduit invert

DS Invert Level = ZP2 + Z

Where Z is node invert elevation (from Data Group D1)

If optional Data Group BB is included in the SWMM4 datafile:

JELEV	Downstream Invert Level
0	ZP2 + Z
>0	ZP2

ROUGH

Manning Coefficient (not required for NKLASS type 8)

Roughness

STHETA

NKLASS	Parameter
6	Slope of left hand side of trapezoid (Horizontal/Vertical)
7	Channel exponent
8	Cross Section ID

See Shape (NKLASS) Conversion below

SPHI

NKLASS	Parameter
6	Slope of right hand side of trapezoid (Horizontal/Vertical)

See Shape (NKLASS) Conversion below

Shape (NKLASS) Conversion

SWMM4 NKLASS

Conduit Shape

InfoWorks ICM Shape ID

Conversion Notes

Circular

CIRC

Rectangular

RECT

Horseshoe

HORSESHOE

User defined shape

Egg

SWMMEGG

User defined shape

Baskethandle

BASKETHANDLE

User defined shape

Trapezoidal Channel

Channel Section created to represent trapezoidal section with following (X, Z) co-ordinates:

Co-ordinates	Conversion
(X1, Z1)	-(WIDE/2)+(DEEP x STHETA), DEEP
(X2, Z2)	-(WIDE/2),0
(X3, Z3)	WIDE/2,0
(X4, Z4)	(WIDE/2)+(DEEP X SPHI), DEEP

Parabolic / Power Function Channel

NCOND

User-defined symmetric shape created with 15 equally spaced points between Z = 0 and Z = DEEP.

Width = 2.a.y1/STHETA

where a is such that width=WIDE at y=DEEP

Irregular (natural) channel

Channel Section created using data from C2-C4 Data Groups

Flap Gate Conversion

The importer creates a user defined headloss curve named FLAP. The curve is defined with a very high headloss coefficient at negative velocities and zero headloss at zero velocity and at positive velocities. The curve is applied to the conduit long section as follows:

NKLASS < 0 represents a flap gate that only allows water to move from the downstream node to the upstream node. The importer sets the downstream headloss type of the conduit to FLAP and the downstream headloss coefficient to 1.0.
LEN < 0 represents a flap gate that only allows water to move from the upstream node to the downstream node. The importer sets the upstream headloss type of the conduit to FLAP and the upstream headloss coefficient to 1.0.

Data Group C2, C3, C4 - Irregular Channel Data

The importer creates channel shapes for conduits of type NKLASS=8 (irregular) channels. The data required to create the channel cross-section are in Data Groups C2 - C4.

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Data Group C2 - Channel Roughness

SWMM4	Description	InfoWorks ICM Data Field
XNL	Manning's n for left overbank	Rough. (up to left panel marker)
XNR	Manning's n for right overbank	Rough. (from right panel marker)
XNCH	Manning's n for channel	Rough. (between left and right panel markers)

Data Group C3 - Cross Section Data

SWMM4	Description	Conversion Notes
SECNO	Cross Section ID	Used as a cross reference to conduit data in Data Group C1
NUMST	Number of stations on the cross section	Number of entries in Cross-Section Shape grid
STCHL	Station of left bank of channel	Position of left bank panel marker
STCHR	Station of right bank of channel	Position of right bank panel marker
XLOBL	Not Required. Enter 0.0	Not Used
XLOBR	Not Required. Enter 0.0	Not Used
LEN(N)	Length of channel reach represented by cross section	Length of section
PXSECR	Multiplication Factor to modify horizontal dimensions of cross section	Multiplies X Co-ordinates by PXSECR value
PSXECE	Constant to be added to cross section elevation data	Not used

Data Group C4 - Cross-Section Profile

SWMM4	Description	InfoWorks ICM Data Field
EL(i)	Cross Section elevation at Station (i).	Depth
STA(i)	Position of Station number (i)	X Coord.

Data Group D1 - Junction Data

Nodes are set to node type "Manhole" by default, unless the node is defined as a Storage Junction (Data Group E1/E2), or an outfall (Data Group I1/I2)

Chamber and shaft areas are set to a default of AMEN (Data Group B2), unless the node is a Storage Junction (Data Group E1).

SWMM4	Description	InfoWorks ICM Data Field
JUN	Junction ID	Node ID
GRELEV	Ground elevation	Ground Level
Z	Invert elevation	Chamber Floor Level
QINST	Net constant flow into junction	User Number 1 Not converted. Create a subcatchment to apply constant inflow.
Y0	Initial depth above junction invert elevation	User Number 2 (Initial depth does not need to be set as InfoWorks ICM automatically initialises levels)
XLOC	X coordinate	X
YLOC	Y coordinate	Y

Data Group E1, E2 - Storage Junctions

Storage nodes are imported with entries in the Level/Plan Area grid populated from SWMM4 stage/storage area points, or from values generated by using a power function.

SWMM4	Description	InfoWorks ICM Data Field
JSTORE	Junction ID (used as a cross reference to node data in Data Group D1)	Node ID
ZTOP	Elevation of junction crown	Chamber Roof Level
ASTORE	Constant surface area ASTORE < 0 indicates a variable area storage junction	Chamber cross-sectional area (shaft area set to zero) If ASTORE <0 node type is changed to "STORAGE"
NUMST	Number of stage/storage area points (only required if ASTORE < 0) If NUMST = -2, stage/storage area points are generated using a power function	Number of entries in Storage Array data field of Node. If NUMST = -2 entries in the Storage Array field are generated using a power function

Variable Area Storage Junctions NUMST > -2

SWMM4

Description

InfoWorks ICM Data Field

QCURVE(1,(i))

Surface area of storage junction at depth point (i)

Area in Storage Array data field of Node

QCURVE(2,(i))

Depth above junction invert at point (i)

If optional Data Group BB is included in the SWMM4 data file, the interpretation of QCURVE(2,(i)) is dependent on the value of JELEV.

JELEV	Description
<3	Depth above junction invert
>=3	Absolute elevation above junction invert

Level in Storage Array data fields of Node:

Level = QCURVE(2,(i)) + Z

Where Z is node invert elevation (from Data Group D1)

If optional Data Group BB is included in the SWMM4 datafile:

JELEV	Upstream Invert Level
<3	ZP1 + Z
>=3	ZP1

Variable Area Storage Junctions NUMST = -2

SWMM4	Description	Conversion
QCURVE(1,1)	Coefficient of the power function	The importer creates a stage-area table with 15 values at regular values between Z and ZTOP using power function: A=QCURVE(1,1) x DepthQCURVE(2,1) The importer adds AMEN (default plan area for all manholes specified in Data Group B2) to each area.
QCURVE(2,1)	Exponent of the power function	See QCURVE(1,1)

SWMM4

Description

Conversion

QCURVE(1,1)

Coefficient of the power function

The importer creates a stage-area table with 15 values at regular values between Z and ZTOP using power function:

A=QCURVE(1,1) x DepthQCURVE(2,1)

The importer adds AMEN (default plan area for all manholes specified in Data Group B2) to each area.

QCURVE(2,1)

Exponent of the power function

See QCURVE(1,1)

Data Group F1 - Orifice Data

Orifice links are set to type "ORIFIC".

SWMM4

Description

InfoWorks ICM Data Field

NJUNC(1)

Junction ID of junction containing orifice

US Node ID

NJUNC(2)

Junction ID of junction to which orifice discharges to

DS Node ID

NKLASS

Type of orifice

NKLASS	Orifice
1	side outlet
2	bottom outlet
3	time history side outlet
4	time history bottom outlet

NKLASS = 1 or 3, Side Outlet created

NKLASS = 2 or 4, Bottom Outlet created

AORIF

Orifice Area

Diameter calculated as:

CORIF

Orifice Discharge Coefficient

Discharge Coefficient calculated as:

Distance of orifice invert above junction floor (for side outlet orifices only)

If optional Data Group BB is included in the SWMM4 data file, the interpretation of ZP is dependent on the value of JELEV.

JELEV	Description
<4	Distance of orifice invert above junction invert
4	Absolute elevation of orifice invert

Side outlet (NKLASS = 1 or 3):

Invert Level = ZP + Z

Where Z is upstream node chamber floor (from Data Group D1)

If optional Data Group BB is included in the SWMM4 datafile:

JELEV	Invert Level
< 4	ZP + Z
4	ZP

Bottom outlet (NKLASS = 2 or 4):

Invert Level = Z - (0.96 x Dia.)

Where Z is upstream node chamber floor (from Data Group D1)

Dia. = Orifice Diameter

The converter resets the upstream chamber invert level to prevent validation errors.

Data Group G1 - Weir Data

SWMM4

Description

InfoWorks ICM Data Field

NJUNC(1)

Junction ID at which weir is located

US Node ID

NJUNC(2)

Junction ID to which weir discharges

DS Node ID

KWEIR

Type of weir

YCREST

Height of weir crest above invert

If optional Data Group BB is included in the SWMM4 data file, the interpretation of YCREST is dependent on the value of JELEV.

JELEV	Description
<4	Distance of weir crest above us node invert
4	Absolute elevation of weir crest

Crest = YCREST + Z

Where Z is us node invert elevation (from Data Group D1)

If optional Data Group BB is included in the SWMM4 datafile:

JELEV	Crest
<4	YCREST + Z
4	YCREST

YTOP

Height to top of weir opening above invert

If optional Data Group BB is included in the SWMM4 data file, the interpretation of YTOP is dependent on the value of JELEV.

JELEV	Description
<4	Distance of top of weir opening above us node invert
4	Absolute elevation of top of weir opening

Roof Height = YTOP - YCREST

WLEN

Weir length

Width

COEF

Coefficient of discharge

Discharge Coefficient

Weir equations differ between SWMM and InfoWorks ICM and it may be necessary to calculate and apply an appropriate conversion factor.

Data Group H1 - Pump Data

SWMM4

Description

InfoWorks ICM Data Field

IPTYP

Pump Type

IPTYP

Pump Type

Off-line pump with wet well

Rate of pumping depends upon wet well volume

In-line lift pump

Rate of pumping depends upon level of water surface

Three-point head-discharge pump curve

Rate of pumping depends on head difference over pump

Link Type

IPTYP	Link Type
1	FIXPMP
2	FIXPMP
3	ROTPMP

For pumps of IPTYP3 where PRATE(1) does not equal 0, an additional pump of type FIXPMP with discharge PRATE(1) will be added. PRATE(1) will be subtracted from all flow entries in the head-discharge table of the rotodynamic pump.

NJUNC(1)

Junction ID of junction being pumped

US Node ID

NJUNC(2)

Junction ID of junction being pumped to

DS Node ID

NRATES

Number of PRATE/VRATE Pairs

This parameter is only entered if optional parameter IPRATE in Data Group BB = 1

By default, three PRATE/VRATE pairs are used

Number of pump curve entries

PRATE(1)

Lower pumping rate

See Pump Conversion section below

PRATE(2)

Mid pumping rate

See Pump Conversion section below

PRATE(3)

High pumping rate

See Pump Conversion section below

VRATE(1)

IPTYP	Description
1	Wet well volume for mid rate pumps to start
2	Junction depth for mid rate pumps to start
3	Head difference associated with lowest pumping rate

See Pump Conversion section below

VRATE(2)

IPTYP	Description
1	Wet well volume for high rate pumps to start
2	Junction depth for high rate pumps to start
3	Head difference associated with mid pumping rate

See Pump Conversion section below

VRATE(3)

IPTYP	Description
1	Wet well capacity
2	-
3	Head difference associated with highest pumping rate

See Pump Conversion section below

VWELL

Initial wet well volume/Initial depth in pump inflow junction

Not used

PON

Pump inflow junction depth to turn pump ON

If optional Data Group BB is included in the SWMM4 data file, the interpretation of PON is dependent on the value of JELEV.

JELEV	Description
<4	Depth at pump inflow junction for Pump Switch On value
4	Absolute elevation of Pump Switch On value

Switch On Level = PON + Z

Where Z is us node invert elevation (from Data Group D1)

If optional Data Group BB is included in the SWMM4 datafile:

JELEV	Switch On Level
<4	PON + Z
4	PON

POFF

Pump inflow junction depth to turn pump OFF

If optional Data Group BB is included in the SWMM4 data file, the interpretation of POFF is dependent on the value of JELEV.

JELEV	Description
<4	Depth at pump inflow junction for Pump Switch Off value
4	Absolute elevation of Pump Switch Off value

Switch Off Level = POFF + Z

Where Z is us node invert elevation (from Data Group D1)

If optional Data Group BB is included in the SWMM4 datafile:

JELEV	Switch Off Level
<4	POFF + Z
4	POFF

Pump Conversion

If IPTYP =1 the importer uses the node geometry to convert volumes in VRATE to levels.

For IPTYP = 1 and 2 the importer creates a fixed pump for each distinct discharge value in PRATE. The first pump has discharge PRATE(1), the second PRATE(2) and the third PRATE(3). The first pump has discharge PRATE(1) and switch on = switch off = Chamber floor level. Subsequent pumps have switch on = switch off = level where discharge changes.

For IPTYP = 3, the importer creates a rotodynamic head-discharge relationship from PRATE and VRATE pairs. If PRATE(1) is greater than zero, the importer adds a fixed discharge pump with discharge PRATE(1). PRATE(1) is then subtracted from all flow entries in the head-discharge table of the rotodynamic pump.

Data Group I1 - Outfalls without Tide Gates

The importer searches for a node with Node IDequal to SWMM4 variable JFREE and changes the node type to Outfall.

Data Group I2 - Outfalls with Tide Gates

The importer searches for a node with Node IDequal to SWMM4 variable JGATE.

The converter creates an outfall node and creates a flap valve between JGATE node and the new outfall.

The diameter of the flap valve is set to the smaller of the height or width of the conduit connected to JGATE.

Importing SWMM4 Network Data