Appendix L SWMM GeoPackage Format

This appendix contains the layers and attributes used in the SWMM GeoPackage format which can be converted to and from EPA SWMM inp files, as discussed in Section 6.3.1.

L.1 SWMM GeoPackage Layer List

Table L.1: SWMM Input layers

Category	Input	Description	Geometry	Table
BC	Inflows	Specifies external hydrographs and pollutographs that enter the drainage system at specific nodes.	Point	Table L.2
Curves	Curves	Describes a relationship between two variables in tabular format.	No Geometry	Table L.3
Curves	Timeseries	Describes how a quantity varies over time.	No Geometry	Table L.4
Groundwater	Aquifers	Supplies parameters for each unconfined groundwater aquifer in the study area. Aquifers consist of two zones – a lower saturated zone and an upper unsaturated zone with a moving boundary between the two.	No Geometry	Table L.5
Groundwater	Groundwater	Supplies parameters that determine the rate of groundwater flow between the aquifer underneath a subcatchment and a node of the conveyance system.	Region	Table L.6
Groundwater	GWF	Defines custom groundwater flow equations for specific subcatchments.	Region	Table L.7
Hydrology	Adjustments	Specifies optional monthly adjustments to be made to temperature, evaporation rate, rainfall intensity and hydraulic conductivity in each time period of a simulation.	No Geometry	Table L.8
Hydrology	Evaporation	Specifies how daily potential evaporation rates vary with time for the study area.	No Geometry	Table L.9
Hydrology	Hydrographs	Specifies the shapes of the triangular unit hydrographs that determine the amount of rainfall-dependent infiltration/inflow (RDII) entering the drainage system.	No Geometry	Table L.10
Hydrology	Patterns	Specifies time patterns of dry weather flow or quality in the form of adjustment factors applied as multipliers to baseline values.	No Geometry	Table L.11
Hydrology	Raingages	Identifies each rain gage that provides rainfall data for the study area.	No Geometry	Table L.12
Hydrology	RDII	Specifies the parameters that describe rainfall-dependent infiltration/inflow (RDII) entering the drainage system at specific nodes.	Point	Table L.13
Hydrology	Snowpacks	Specifies parameters that govern how snowfall accumulates and melts on the plowable, impervious and pervious surfaces of subcatchments.	No Geometry	Table L.14
Hydrology	Temperature	Specifies daily air temperatures, monthly wind speed, and various snowmelt parameters for the study area. Required only when snowmelt is being modeled or when evaporation rates are computed from daily temperatures or are read from an external climate file.	No Geometry	Table L.15
Inlets	Inlet Usage	Assigns inlet structures to specific street and open channel conduits.	Point	Table L.16
Inlets	Inlets	Defines inlet structure designs used to capture street and channel flow that are sent to below ground sewers.	No Geometry	Table L.17
LID	Lid_controls	Defines scale-independent LID controls that can be deployed within subcatchments.	No Geometry	Table L.18
LID	Lid_usage	Deploys LID controls within specific subcatchment areas.	Region	Table L.19
Links	Conduits	Identifies each conduit link of the drainage system. Conduits are pipes or channels that convey water from one node to another.	Line	Table L.20
Links	Controls	Determines how pumps and regulators will be adjusted based on simulation time or conditions at specific nodes and links.	No Geometry	Table L.21
Links	Losses	Specifies minor head loss coefficients, flap gates, and seepage rates for conduits.	Line	Contained within Table L.20
Links	Orifices	Identifies each orifice link of the drainage system. An orifice link serves to limit the flow exiting a node and is often used to model flow diversions and storage node outlets.	Line	Table L.22
Links	Outlets	Identifies each outlet flow control device of the drainage system. These are devices used to model outflows from storage units or flow diversions that have a user-defined relationship between flow rate and water depth.	Line	Table L.23
Links	Pumps	Identifies each pump link of the drainage system.	Line	Table L.24
Links	Streets	Describes the cross-section geometry of conduits that represent streets.	No Geometry	Table L.25
Links	Transects	Describes the cross-section geometry of natural channels or conduits with irregular shapes following the HEC-2 data format.	No Geometry	Table L.26 and Table L.27
Links	Weirs	Identifies each weir link of the drainage system. Weirs are used to model flow diversions and storage node outlets.	Line	Table L.28
Links	Xsections	Provides cross-section geometric data for conduit and regulator links of the drainage system.	Line	Contained within Table L.20, Table L.22 and Table L.28.
Nodes	Dividers	Identifies each flow divider node of the drainage system. Flow dividers are junctions with exactly two outflow conduits where the total outflow is divided between the two in a prescribed manner.	Point	Table L.29
Nodes	DWF	Specifies dry weather flow and its quality entering the drainage system at specific nodes.	No Geometry	Table L.30
Nodes	Junctions	Identifies each junction node of the drainage system. Junctions are points in space where channels and pipes connect together. For sewer systems they can be either connection fittings or manholes.	Point	Table L.31
Nodes	Outfalls	Identifies each outfall node (i.e., final downstream boundary) of the drainage system and the corresponding water stage elevation. Only one link can be incident on an outfall node.	Point	Table L.32
Nodes	Storage	Identifies each storage node of the drainage system. Storage nodes can have any shape as specified by a surface area versus water depth relation.	Point	Table L.33
Project	Files	Identifies optional interface files used or saved by a run.	No Geometry	Table L.34
Project	Options	Provides values for various analysis options.	No Geometry	Table L.35
Project	Report	Describes the contents of the report file that SWMM produces.	No Geometry	Table L.36
Project	Title	Attaches a descriptive title to the project being analyzed.	No Geometry	Table L.37
Hydrology	Infiltration	Supplies infiltration parameters for each subcatchment. Rainfall lost to infiltration only occurs over the pervious subarea of a subcatchment.	Region	Contained within Table L.38
Hydrology	Subareas	Supplies information about pervious and impervious areas for each subcatchment. Each subcatchment can consist of a pervious subarea, an impervious subarea with depression storage, and an impervious subarea without depression storage.	Region	Contained within Table L.38
Hydrology	Subcatchments	Identifies each subcatchment within the study area. Subcatchments are land area units that generate runoff from rainfall.	Region	Table L.38
WQ	Buildup	Specifies the rate that pollutants build up over different land uses between rain events.	No Geometry	Table L.39
WQ	Coverages	Specifies the percentage of a subcatchment’s area that is covered by each category of land use.	Region	Table L.40
WQ	Landuses	Identifies the various categories of land uses within the drainage area. Each subcatchment area can be assigned a different mix of land uses. Each land use can be subjected to a different street sweeping schedule. Land uses are only used in conjunction with pollutant buildup and wash off.	No Geometry	Table L.41
WQ	Loadings	Specifies the pollutant buildup that exists on each subcatchment at the start of a simulation.	Region	Table L.42
WQ	Pollutants	Identifies the pollutants being analyzed.	No Geometry	Table L.43
WQ	Treatment	Specifies the degree of treatment received by pollutants at specific nodes of the drainage system.	Point	Table L.44
WQ	Washoff	Specifies the rate at which pollutants are washed off from different land uses during rain events.	No Geometry	Table L.45

L.2 SWMM GeoPackage Layer Descriptions

Table L.2: Inflows

No.	Default GIS Attribute Name	Description	Type
1	Node	Name of the node where external inflow enters.	Char
2	Type	FLOW or <name of a pollutant>.	Char
3	Tseries	Name of a time series in the TIMESERIES section describing how external flow or pollutant loading varies with time.	Char
4	PollutType	<name of a pollutant>: CONCEN: if pollutant inflow is described as a concentration (default). MASS: if it is described as a mass flow rate. FLOW: Not Used.	Char
5	Mfactor	The factor that converts the inflow’s mass flow rate units into the project’s mass units per second, where the project’s mass units are those specified for the pollutant in the POLLUTANTS section (default is 1.0).	Float
6	SeriesType	CONCEN if pollutant is described as a concentration, MASS if it is described as a mass flow rate (default is CONCEN)	Char
7	Factor1	Generally 1 for FLOW; Mfactor for Pollutant - the factor that converts the inflow’s mass flow rate units into the project’s mass units per second, where the project’s mass units are those specified for the pollutant in the [POLLUTANTS] section (default is 1.0)	Float
8	Sfactor	A scaling factor that multiplies the recorded time series values (default is 1.0).	Float
9	Base	A constant baseline value added to the time series value (default is 0.0).	Float
10	Pat	Name of an optional time pattern in the PATTERNS section used to adjust the baseline value on a periodic basis.	Char

Table L.3: Curves

No.	Default GIS Attribute Name	Description	Type
1	Name	Name assigned to the curve.	Char
2	Type	The type of curve being defined: STORAGE / SHAPE / DIVERSION / TIDAL / PUMP1 / PUMP2 / PUMP3 / PUMP4 / PUMP5 / RATING / CONTROL / WEIR.	Char
3	xval	An X (independent variable) value.	Float
4	yval	The Y (dependent variable) value corresponding to X.	Float

Table L.4: Timeseries

No.	Default GIS Attribute Name	Description	Type
1	Name	Name assigned to the time series.	Char
2	Frame	The name of a file in which the time series data are stored.	Char
3	Date	Date in Month/Day/Year format (e.g., June 15, 2001 would be 6/15/2001).	Char
4	Time	Hours since the start of the simulation, expressed as a decimal number or as hours:minutes (where hours can be greater than 24).	Char
5	Value	A value corresponding to the specified date and time.	Float

Table L.5: Aquifers

No.	Default GIS Attribute Name	Description	Type
1	Name	Name assigned to aquifer.	Char
2	Por	Soil porosity (pore space volume / total volume).	Float
3	WP	Soil wilting point (moisture content of a fully dried soil).	Float
4	FC	Soil field capacity (moisture content of a fully drained soil).	Float
5	Ksat	Saturated hydraulic conductivity (in/hr or mm/hr).	Float
6	Kslope	Slope of the logarithm of hydraulic conductivity versus moisture deficit (porosity minus moisture content) curve (dimensionless).	Float
7	Tslope	Slope of soil tension versus moisture content curve (inches or mm).	Float
8	ETu	Fraction of total evaporation available for evapotranspiration in the upper unsaturated zone.	Float
9	ETs	Maximum depth into the lower saturated zone over which evapotranspiration can occur (ft or m).	Float
10	Seep	Seepage rate from saturated zone to deep groundwater when water table is at ground surface (in/hr or mm/hr).	Float
11	Ebot	Elevation of the bottom of the aquifer (ft or m). Local values can be assigned to specific subcatchments in the GROUNDWATER section.	Float
12	Egw	Groundwater table elevation at start of simulation (ft or m). Local values can be assigned to specific subcatchments in the GROUNDWATER section.	Float
13	Umc	Unsaturated zone moisture content at start of simulation (volumetric fraction). Local values can be assigned to specific subcatchments in the GROUNDWATER section.	Float
14	ETupat	Name of optional monthly time pattern used to adjust the upper zone evaporation fraction for different months of the year.	Float

Table L.6: Groundwater

No.	Default GIS Attribute Name	Description	Type
1	Subcatchment	Subcatchment name.	Char
2	Aquifer	Name of groundwater aquifer underneath the subcatchment.	Char
3	Node	Name of a node in the conveyance system exchanging groundwater with the aquifer.	Char
4	Esurf	Surface elevation of the subcatchment (ft or m).	Float
5	A1	Groundwater flow coefficient (see Equation (L.1) below).	Float
6	B1	Groundwater flow exponent (see Equation (L.1) below).	Float
7	A2	Surface water flow coefficient (see Equation (L.1) below).	Float
8	B2	Surface water flow exponent (see Equation (L.1) below).	Float
9	A3	Surface water – groundwater interaction coefficient (see Equation (L.1) below).	Float
10	Dsw	Fixed depth of surface water at the receiving node (ft or m) (set to zero if surface water depth will vary as computed by flow routing).	Float
11	Egwt	Threshold groundwater table elevation which must be reached before any flow occurs (ft or m). Leave blank (or enter *) to use the elevation of the receiving node’s invert.	Float
12	Ebot	Optional. Elevation of the bottom of the aquifer (ft or m). Can be used to override the values supplied for the subcatchment’s aquifer.	Float
13	Wgr	Optional. Groundwater table elevation at the start of the simulation (ft or m). Can be used to override the values supplied for the subcatchment’s aquifer.	Float
14	Umc	Optional. Unsaturated zone moisture content at start of simulation (volumetric fraction). Can be used to override the values supplied for the subcatchment’s aquifer.	Float

The flow coefficients are used in the following equation that determines the lateral groundwater flow rate based on groundwater and surface water elevations:

\[\begin{equation} Q_{L} = A1 (H_{gw} – H_{cb})^{B1} – A2 (H_{sw} – H_{cb})^{B2} + A3 H_{gw} H_{sw} \tag{L.1} \end{equation}\]

Where:

• \(Q_{L}\) = lateral groundwater flow (cfs per acre or cms per hectare),
• \(H_{gw}\) = height of saturated zone above the bottom of the aquifer (ft or m),
• \(H_{sw}\) = height of surface water at the receiving node above the aquifer bottom (ft or m),
• \(H_{cb}\) = height of the channel bottom above the aquifer bottom (ft or m).

Table L.7: GWF

No.	Default GIS Attribute Name	Description	Type
1	Subcatchment	Subcatchment name.	Char
2	Type	Lateral: to designate an expression for Lateral groundwater flow (to a node of the conveyance network). Deep: for vertical loss to Deep groundwater	Char
3	Expr	A math formula expressing the rate of groundwater flow (in cfs per acre for lateral flow or in/hr for deep flow (cms per hectare and mm/hr if using metric units) as a function of the following variables: Hgw: for height of the groundwater table Hsw: for height of the surface water Hcb: for height of the channel bottom Hgs: for height of ground surface Where all heights are relative to the aquifer bottom and have units of either feet or meters (if using metric units): Ks: for saturated hydraulic conductivity in in/hr or mm/hr K: for unsaturated hydraulic conductivity in in/hr or mm/hr Theta: for moisture content of the unsaturated zone Phi: for aquifer soil porosity Fi: for infiltration rate from the ground surface in in/hr or mm/hr Fu: for percolation rate from the upper unsaturated zone in in/hr or mm/hr A: for subcatchment area in acres or hectares	Char

Table L.8: Adjustments

No.	Default GIS Attribute Name	Description	Type
1	Format	Temperature: t1..t12 Evaporation: e1..e12 Rainfall: r1..r12 Conductivity: c1..c12	Char
2	Month1	t1: adjustments to temperature in January, as plus or minus degrees F (degrees C if using metric units). e1: adjustments to evaporation rate in January, as plus or minus in/day (mm/day if using metric units). r1: multipliers applied to precipitation rate in January. c1: multipliers applied to soil hydraulic conductivity in January used in either Horton or Green-Ampt infiltration.	Float
3	Month2	As above, for February.	Float
4	Month3	As above, for March.	Float
5	Month4	As above, for April.	Float
6	Month5	As above, for May.	Float
7	Month6	As above, for June.	Float
8	Month7	As above, for July.	Float
9	Month8	As above, for August.	Float
10	Month9	As above, for September.	Float
11	Month10	As above, for October.	Float
12	Month11	As above, for November.	Float
13	Month12	As above, for December.	Float

Table L.9: Evaporation

No.	Default GIS Attribute Name	Description	Type
1	Format	CONSTANT: applies a constant evaporation rate. MONTHLY: applies a constant evaporation rate per month. TIMESERIES: applies the specified timeseries. TEMPERATURE: indicates that evaporation rates will be computed from the daily air temperatures contained in an external climate file whose name is provided in the TEMPERATURE section. This method also uses the site’s latitude, which can also be specified in the TEMPERATURE section. FILE: indicates that evaporation data will be read directly from the same external climate file used for air temperatures as specified in the TEMPERATURE section. Supplying monthly pan coefficients for these data is optional. RECOVERY: identifies an optional monthly time pattern of multipliers used to modify infiltration recovery rates during dry periods. For example, if the normal infiltration recovery rate was 1% during a specific time period and a pattern factor of 0.8 applied to this period, then the actual recovery rate would be 0.8%. DRY_ONLY: determines if evaporation only occurs during periods with no precipitation. The default is NO. Note: The evaporation rates provided in this section are potential rates. The actual amount of water evaporated will depend on the amount available as a simulation progresses.	Char
2	Evap	CONSTANT: constant evaporation rate (in/day or mm/day).	Float
3	e1	MONTHLY: evaporation rate in January (in/day or mm/day).	Float
4	e2	MONTHLY: evaporation rate in February (in/day or mm/day).	Float
5	e3	MONTHLY: evaporation rate in March (in/day or mm/day).	Float
6	e4	MONTHLY: evaporation rate in April (in/day or mm/day).	Float
7	e5	MONTHLY: evaporation rate in May (in/day or mm/day).	Float
8	e6	MONTHLY: evaporation rate in June (in/day or mm/day).	Float
9	e7	MONTHLY: evaporation rate in July (in/day or mm/day).	Float
10	e8	MONTHLY: evaporation rate in August (in/day or mm/day).	Float
11	e9	MONTHLY: evaporation rate in September (in/day or mm/day).	Float
12	e10	MONTHLY: evaporation rate in October (in/day or mm/day if using metric units).	Float
13	e11	MONTHLY: evaporation rate in November (in/day or mm/day if using metric units).	Float
14	e12	MONTHLY: evaporation rate in December (in/day or mm/day if using metric units).	Float
15	Tseries	TIMESERIES: name of a time series in the TIMESERIES section with evaporation data.	Char
16	p1	FILE: pan coefficient for January.	Float
17	p2	FILE: pan coefficient for February.	Float
18	p3	FILE: pan coefficient for March.	Float
19	p4	FILE: pan coefficient for April.	Float
20	p5	FILE: pan coefficient for May.	Float
21	p6	FILE: pan coefficient for June.	Float
22	p7	FILE: pan coefficient for July.	Float
23	p8	FILE: pan coefficient for August.	Float
24	p9	FILE: pan coefficient for September.	Float
25	p10	FILE: pan coefficient for October.	Float
26	p11	FILE: pan coefficient for November.	Float
27	p12	FILE: pan coefficient for December.	Float
28	patternID	RECOVERY: Name of a monthly time pattern.	Char
29	Value	DRY_ONLY: Yes or No. Determines if evaporation only occurs during periods with no precipitation. The Default is No.	Char

Table L.10: Hydrographs

No.	Default GIS Attribute Name	Description	Type
1	Name	Name assigned to a unit hydrograph group.	Char
2	RaingageOrMonth	Name of the rain gage used by the unit hydrograph group or month of the year (e.g., JAN, FEB, etc. or ALL for all months).	Char
3	Term	Three separate unit hydrographs, that represent the short-term, medium-term, and long-term RDII responses, can be defined for each month (or all months taken together). Use either SHORT, MEDIUM, or LONG.	Char
4	R	Response ratio for the unit hydrograph. The response ratio (R) is the fraction of a unit of rainfall depth that becomes RDII. The sum of the ratios for a set of three hydrographs does not have to equal 1.0.	Float
5	T	Time to peak (hours) for the unit hydrograph.	Float
6	K	Recession limb ratio for the unit hydrograph. The recession limb ratio (K) is the ratio of the duration of the hydrograph’s recession limb to the time to peak (T) making the hydrograph time base equal to T*(1+K) hours. The area under each unit hydrograph is 1 inch (or mm if using metric units).	Float
7	Dmax	Optional. Maximum initial abstraction depth available (in rain depth units). If not supplied then the default is no initial abstraction.	Float
8	Drec	Optional. Initial abstraction recovery rate (in rain depth units per day). If not supplied then the default is no initial abstraction.	Float
9	D0	Optional. Initial abstraction depth already filled at the start of the simulation (in rain depth units). If not supplied then the default is no initial abstraction.	Float

Table L.11: Patterns

No.	Default GIS Attribute Name	Description	Type
1	Name	Name used to identify the pattern.	Char
2	Interval	MONTHLY: Used to set monthly pattern factors for dry weather flow constituents. DAILY: Used to set dry weather pattern factors for each day of the week, where Sunday is day 1. HOURLY: Used to set dry weather factors for each hour of the day starting from midnight. WEEKEND: If these factors are different for weekend days than for weekday days then the WEEKEND format can be used to specify hourly adjustment factors just for weekends. More than one line can be used to enter a pattern’s factors by repeating the pattern’s name (but not the pattern type) at the beginning of each additional line. The pattern factors are applied as multipliers to any baseline dry weather flows or quality concentrations supplied in the DWF section.	Char
3	Factor1	MONTHLY: factor for January DAILY: factor for Sunday HOURLY: factor for 0:00AM.	Float
4	Factor2	MONTHLY: factor for February DAILY: factor for Monday HOURLY: factor for 1:00AM.	Float
5	Factor3	MONTHLY: factor for March DAILY: factor for Tuesday HOURLY: factor for 2:00AM.	Float
6	Factor4	MONTHLY: factor for April DAILY: factor for Wednesday HOURLY: factor for 3:00AM.	Float
7	Factor5	MONTHLY: factor for May DAILY: factor for Thursday HOURLY: factor for 4:00AM.	Float
8	Factor6	MONTHLY: factor for June DAILY: factor for Friday HOURLY: factor for 5:00AM.	Float
9	Factor7	MONTHLY: factor for July DAILY: factor for Saturday HOURLY: factor for 6:00AM.	Float
10	Factor8	MONTHLY: factor for August DAILY: not used. HOURLY: factor for 7:00AM.	Float
11	Factor9	MONTHLY: factor for September DAILY: not used. HOURLY: factor for 8:00AM.	Float
12	Factor10	MONTHLY: factor for October DAILY: not used. HOURLY: factor for 9:00AM.	Float
13	Factor11	MONTHLY: factor for November DAILY: not used. HOURLY: factor for 10:00AM.	Float
14	Factor12	MONTHLY: factor for December DAILY: not used. HOURLY: factor for 11:00AM.	Float
15	Factor13	MONTHLY and DAILY: not used. HOURLY: factor for 12:00PM.	Float
16	Factor14	MONTHLY and DAILY: not used. HOURLY: factor for 13:00PM.	Float
17	Factor15	MONTHLY and DAILY: not used. HOURLY: factor for 14:00PM.	Float
18	Factor16	MONTHLY and DAILY: not used. HOURLY: factor for 15:00PM.	Float
19	Factor17	MONTHLY and DAILY: not used. HOURLY: factor for 16:00PM.	Float
20	Factor18	MONTHLY and DAILY: not used. HOURLY: factor for 17:00PM.	Float
21	Factor19	MONTHLY and DAILY: not used. HOURLY: factor for 18:00PM.	Float
22	Factor20	MONTHLY and DAILY: not used. HOURLY: factor for 19:00PM.	Float
23	Factor21	MONTHLY and DAILY: not used. HOURLY: factor for 20:00PM.	Float
24	Factor22	MONTHLY and DAILY: not used. HOURLY: factor for 21:00PM.	Float
25	Factor23	MONTHLY and DAILY: not used. HOURLY: factor for 22:00PM.	Float
26	Factor24	MONTHLY and DAILY: not used. HOURLY: factor for 23:00PM.	Float

Table L.12: Raingages

No.	Default GIS Attribute Name	Description	Type
1	Name	Name assigned to rain gage.	Char
2	Form	Form of recorded rainfall, either INTENSITY, VOLUME or CUMULATIVE.	Char
3	Intvl	Time interval between gage readings in decimal hours or hours:minutes format (e.g., 0:15 for 15-minute readings).	Char
4	SnowCatchDeficiency	Snow catch deficiency correction factor (use 1.0 for no adjustment).	Float
5	Format	Either TIMESERIES or FILE.	Char
6	Tseries	TIMESERIES: Name of a time series in the TIMESERIES section with rainfall data.	Char
7	Fname	FILE: Name of an external file with rainfall data. Enclose the external file name in double quotes if it contains spaces and include its full path if it resides in a different directory than the SWMM input file.	Char
8	Sta	FILE: Name of the recording station in a user-prepared formatted rain file. Only required when using a user-prepared formatted rainfall file.	Char
9	Units	FILE: Rain depth units for the data in a user-prepared formatted rain file, either inches or millimeters if using metric units. Only required when using a user-prepared formatted rainfall file.	Char

Table L.13: RDII

No.	Default GIS Attribute Name	Description	Type
1	Node	Name of a node receiving RDII flow.	Char
2	UHgroup	Name of an RDII unit hydrograph group appearing in the HYDROGRAPHS section.	Char
3	SewerArea	Area of the sewershed that contributes RDII to the node (acres or hectares if using metric units).	Float

Table L.14: Snowpacks

No.	Default GIS Attribute Name	Description	Type
1	Name	Name assigned to snowpack parameter set .	Char
2	Type	PLOWABLE: contains parameters for the impervious area of a subcatchment that is subject to snow removal by plowing but not to areal depletion. This area is the fraction SNN0 of the total impervious area. IMPERVIOUS: contains parameter values for the remaining impervious area. PERVIOUS: contains parameter values for the entire pervious area. REMOVAL: describes how snow removed from the plowable area is transferred onto other areas. The various transfer fractions should sum to no more than 1.0. If the line is omitted then no snow removal takes place.	Char
3	Cmin	PLOWABLE, IMPERVIOUS and PERVIOUS: Minimum melt coefficient (in/hr-deg F or mm/hr-deg C if using metric units). REMOVAL: Not Used.	Float
4	Cmax	PLOWABLE, IMPERVIOUS and PERVIOUS: Maximum melt coefficient (in/hr-deg F or mm/hr-deg C if using metric units). REMOVAL: Not Used.	Float
5	Tbase	PLOWABLE, IMPERVIOUS and PERVIOUS: Snow melt base temperature (deg F or deg C if using metric units). REMOVAL: Not Used.	Float
6	FWF	PLOWABLE, IMPERVIOUS and PERVIOUS: Ratio of free water holding capacity to snow depth (fraction). REMOVAL: Not Used.	Float
7	SD0	PLOWABLE, IMPERVIOUS and PERVIOUS: Initial snow depth (water equivalent in or mm if using metric units). REMOVAL: Not Used.	Float
8	FW0	PLOWABLE, IMPERVIOUS and PERVIOUS: Initial free water in pack (in or mm if using metric units). REMOVAL: Not Used.	Float
9	SNN0	PLOWABLE: Fraction of impervious area that can be plowed. IMPERVIOUS, PERVIOUS and REMOVAL: Not Used.	Float
10	SD100	IMPERVIOUS and PERVIOUS: Snow depth above which there is 100% cover (water equivalent in or mm if using metric units). PLOWABLE and REMOVAL: Not Used.	Float
11	Dplow	REMOVAL: Depth of snow on plowable areas at which snow removal begins (in or mm if using metric units). PLOWABLE, IMPERVIOUS and PERVIOUS: Not Used.	Char
12	Fout	REMOVAL: Fraction of snow on plowable area transferred out of watershed. PLOWABLE, IMPERVIOUS and PERVIOUS: Not Used.	Float
13	Fimp	REMOVAL: Fraction of snow on plowable area transferred to impervious area by plowing. PLOWABLE, IMPERVIOUS and PERVIOUS: Not Used.	Float
14	Fperv	REMOVAL: Fraction of snow on plowable area transferred to pervious area by plowing. PLOWABLE, IMPERVIOUS and PERVIOUS: Not Used.	Float
15	Fimelt	REMOVAL: Fraction of snow on plowable area converted into immediate melt. PLOWABLE, IMPERVIOUS and PERVIOUS: Not Used.	Float
16	Fsub	REMOVAL: Fraction of snow on plowable area transferred to pervious area in another subcatchment. PLOWABLE, IMPERVIOUS and PERVIOUS: Not Used.	Float
17	Scatch	REMOVAL: Name of subcatchment receiving the Fsub fraction of transferred snow. PLOWABLE, IMPERVIOUS and PERVIOUS: Not Used.	Char

Table L.15: Temperature

No.	Default GIS Attribute Name	Description	Type
1	Option	Available options: FILE WINDSPEED MONTHLY SNOWMELT ADC IMPERVIOUS ADC PERVIOUS	Char
2	Value	Name of file or relevent value. Add additional value columns when required.	Char

Table L.16: Inlet Usage

No.	Default GIS Attribute Name	Description	Type
1	Conduit	Name of a street or open channel conduit containing the inlet.	Char
2	Inlet	Name of an inlet structure (from the INLETS section) to use.	Char
3	Node	Name of the sewer node receiving flow captured by the inlet.	Char
4	Number	Optional. Number of replicate inlets placed on each side of the street. Default is 1 (for each side of a two-sided street).	Integer
5	PctClogged	Optional. Degree to which inlet capacity is reduced due to clogging (%). Default is 0.	Float
6	Qmax	Optional. Maximum flow that the inlet can capture (flow units). A Qmax value of 0 indicates that the inlet has no flow restriction. Default is 0.	Float
7	aLocal	Optional. Height of local gutter depression (in or mm). Default is 0. The local gutter depression applies only over the length of the inlet unlike the continuous depression for a STREET cross section which exists over the full curb length.	Float
8	wLocal	Optional. Width of local gutter depression (ft or m). Default is 0. The local gutter depression applies only over the length of the inlet unlike the continuous depression for a STREET cross section which exists over the full curb length.	Float
9	Placement	Optional. AUTOMATIC, ON_GRADE, or ON_SAG. The default inlet placement is AUTOMATIC, meaning that the program uses the network topography to determine whether an inlet operates on-grade or on-sag. On-grade means the inlet is located on a continuous grade. On-sag means the inlet is located at a sag or sump point where all adjacent conduits slope towards the inlet leaving no place for water to flow except into the inlet.	Char

Table L.17: Inlets

No.	Default GIS Attribute Name	Description	Type
1	Name	Name assigned to the inlet structure.	Char
2	Type	Set either GRATE, DROP_GRATE, CURB, DROP_CURB, SLOTTED or CUSTOM.	Char
3	Grate_Length	GRATE: length of the inlet parallel to the street curb (ft or m).	Float
4	Grate_Width	GRATE: width of a GRATE inlet (ft or m).	Float
5	Grate_Type	GRATE: type of GRATE used, options availabe: P_BAR-50: Parallel bar grate with bar spacing 1-7/8-in on center. P_BAR-50X100: Parallel bar grate with bar spacing 1-7/8-in on center and 3/8-in diameter lateral rods spaced at 4-in on center. P_BAR-30: Parallel bar grate with 1-1/8-in on center bar spacing. CURVED_VANE: Curved vane grate with 3-1/4-in longitudinal bar and 4-1/4-in transverse bar spacing on center. TILT_BAR-45: 45 degree tilt bar grate with 2-1/4-in longitudinal bar and 4-in transverse bar spacing on center. TILT_BAR-30: 30 degree tilt bar grate with 3-1/4-in and 4-in on center longitudinal and lateral bar spacing respectively. RETICULINE: “Honeycomb” pattern of lateral bars and longitudinal bearing bars. GENERIC: A generic grate design.	Char
6	Grate_Aopen	GRATE: if type is GENERIC, fraction of grate’s area that is open.	Float
7	Grate_vsplash	GRATE: if type is GENERIC, splash over velocity (ft/s or m/s if using metric units).	Float
8	Curb_Length	CURB: length of the inlet parallel to the street curb (ft or m if using metric units).	Float
9	Curb_Height	CURB: height of a opening inlet (ft or m if using metric units).	Float
10	Curb_Throat	CURB: the throat angle of a CURB opening inlet (HORIZONTAL, INCLINED or VERTICAL).	Char
11	Slotted_Length	SLOTTED: length of a SLOTTED inlet (ft or m if using metric units).	Float
12	Slotted_Width	SLOTTED: width of a SLOTTED inlet (ft or m if using metric units).	Float
13	Custom_Curve	CUSTOM: name of a Rating-type curve (captured flow v. water depth).	Char

Table L.18: LID Controls

No.	Default GIS Attribute Name	Description	Type
1	Name	Name assigned to LID process.	Char
2	Type	BC for bio-retention cell RG for rain garden GR for green roof IT for infiltration trench PP for permeable pavement RB for rain barrel RD for rooftop disconnection VS for vegetative swale	Char
3	surface_StorHt	BC, RG, GR, IT, PP, RD, VS: When confining walls or berms are present this is the maximum depth to which water can pond above the surface of the unit before overflow occurs (in inches or mm). For LIDs that experience overland flow it is the height of any surface depression storage. For swales, it is the height of its trapezoidal cross-section. All other types: Not Used.	Float
4	surface_VegFrac	BC, RG, GR, IT, PP, RD, VS: Fraction of the surface storage volume that is filled with vegetation. All other types: Not Used.	Float
5	surface_Rough	BC, RG, GR, IT, PP, RD, VS: Manning’s coefficient (n) for overland flow over surface soil cover, pavement, roof surface or a vegetative swale. Use 0 for other types of LIDs. If value is 0 then any ponded water that exceeds the surface storage depth is assumed to completely overflow the LID control within a single time step. All other types: Not Used.	Float
6	surface_Slope	BC, RG, GR, IT, PP, RD, VS: slope of a roof surface, pavement surface or vegetative swale (percent). Use 0 for other types of LIDs. If value is 0 then any ponded water that exceeds the surface storage depth is assumed to completely overflow the LID control within a single time step. All other types: Not Used.	Float
7	surface_Xslope	BC, RG, GR, IT, PP, RD, VS: slope (run over rise) of the side walls of a vegetative swale’s cross-section. Use 0 for other types of LIDs. All other types: Not Used.	Float
8	soil_Thick	BC, RG, GR, PP: Thickness of the soil layer (inches or mm if using metric units). Optional for PP. All other types: Not Used.	Float
9	soil_Por	BC, RG, GR, PP: Soil porosity (pore space volume / total volume). Optional for PP. All other types: Not Used.	Float
10	soil_FC	BC, RG, GR, PP: Soil field capacity (moisture content of a fully drained soil). Optional for PP. All other types: Not Used.	Float
11	soil_WP	BC, RG, GR, PP: Soil wilting point (moisture content of a fully dried soil). Optional for PP. All other types: Not Used.	Float
12	soil_Ksat	BC, RG, GR, PP: Soil’s saturated hydraulic conductivity (in/hr or mm/hr if using metric units). Optional for PP. All other types: Not Used.	Float
13	soil_Kcoeff	BC, RG, GR, PP: Slope of the curve of log (conductivity) versus soil moisture deficit (porosity minus soil moisture) (dimensionless). Optional for PP. All other types: Not Used.	Float
14	soil_Suct	BC, RG, GR, PP: Soil capillary suction (in or mm if using metric units). Optional for PP. All other types: Not Used.	Float
15	pavement_Thick	PP: Thickness of the pavement layer (inches or mm if using metric units). All other types: Not Used.	Float
16	pavement_Vratio	PP: Void ratio (volume of void space relative to the volume of solids in the pavement for continuous systems or for the fill material used in modular systems). Note that porosity = void ratio / (1 + void ratio). All other types: Not Used.	Float
17	pavement_FracImp	PP: Ratio of impervious paver material to total area for modular systems; 0 for continuous porous pavement systems. All other types: Not Used.	Float
18	pavement_Perm	PP: Permeability of the concrete or asphalt used in continuous systems or hydraulic conductivity of the fill material (gravel or sand) used in modular systems (in/hr or mm/hr). All other types: Not Used.	Float
19	pavement_Vclog	PP: the number of pavement layer void volumes of runoff treated it takes to completely clog the pavement. Use a value of 0 to ignore clogging. All other types: Not Used.	Float
20	pavement_Treg	PP: The number of days that the pavement layer is allowed to clog before its permeability is restored, typically by vacuuming its surface. A value of 0 (the default) indicates that no permeability regeneration occurs. All other types: Not Used.	Float
21	pavement_Freg	PP: The fractional degree to which the pavement’s permeability is restored when a regeneration interval is reached. The default is 0 (no restoration) while a value of 1 indicates complete restoration to the original permeability value. Once regeneration occurs the pavement begins to clog once again at a rate determined by Vclog. All other types: Not Used.	Float
22	storage_Height	BC, IT, PP, RB: Thickness of the storage layer or height of a rain barrel (inches or mm if using metric units). All other types: Not Used.	Float
23	storage_Vratio	BC, IT, PP, RB: void ratio (volume of void space relative to the volume of solids in the layer). Note that porosity = void ratio / (1 + void ratio). All other types: Not Used.	Float
24	storage_Seepage	BC, IT, PP, RB: The rate at which water seeps from the layer into the underlying native soil when first constructed (in/hr or mm/hr if using metric units). If there is an impermeable floor or liner below the layer then use a value of 0. All other types: Not Used.	Float
25	storage_Vclog	BC, IT, PP, RB: Number of storage layer void volumes of runoff treated it takes to completely clog the layer. Use a value of 0 to ignore clogging.	Float
26	storage_Covrd	BC, IT, PP, RB: YES (the default) if a rain barrel is covered, NO if it is not. All other types: Not Used.	Char
27	drain_Coeff	RB, RD, BC, IT, PP: Coefficient C that determines the rate of flow through the drain as a function of height of stored water above the drain bottom. For Rooftop Disconnection it is the maximum flow rate (in inches/hour or mm/hour if using metric units) that the roof’s gutters and downspouts can handle before overflowing. Optional for BC, IT, PP. All other types: Not Used.	Float
28	drain_Expon	RB, RD, BC, IT, PP: Exponent n that determines the rate of flow through the drain as a function of height of stored water above the drain outlet. Optional for BC, IT, PP. All other types: Not Used.	Float
29	drain_Offset	RB, RD, BC, IT, PP: Height of the drain line above the bottom of the storage layer or rain barrel (inches or mm if using metric units). Optional for BC, IT, PP. All other types: Not Used.	Float
30	drain_Delay	RB, RD, BC, IT, PP: Number of dry weather hours that must elapse before the drain line in a rain barrel is opened (the line is assumed to be closed once rainfall begins). A value of 0 signifies that the barrel’s drain line is always open and drains continuously.  This parameter is ignored for other types of LIDs. All other types: Not Used.	Float
31	drain_Hopen	RB, RD, BC, IT, PP: The height of water  (in inches or mm) in the drain’s Storage Layer that causes the drain to automatically open. Use 0 to disable this feature. Optional for BC, IT, PP. All other types: Not Used.	Float
32	drain_Hclose	RB, RD, BC, IT, PP: The height of water (in inches or mm) in the drain’s Storage Layer that causes the drain to automatically close. Use 0 to disable this feature. Optional for BC, IT, PP. All other types: Not Used.	Float
33	drain_Qcrv	RB, RD, BC, IT, PP: The name of an optional Control Curve that adjusts the computed drain flow as a function of the head of water above the drain. Leave blank if not applicable. Optional for BC, IT, PP. All other types: Not Used.	Char
34	drainmat_Thick	GR: Thickness of the drainage mat (inches or mm if using metric units). All other types: Not Used.	Float
35	drainmat_Vratio	GR: Ratio of void volume to total volume in the mat. All other types: Not Used.	Char
36	drainmat_Rough	GR: Manning’s coefficient (n) used to compute the horizontal flow rate of drained water through the mat. All other types: Not Used.	Char

Table L.19: LID Usage

No.	Default GIS Attribute Name	Description	Type
1	Subcatchment	Name of the subcatchment using the LID process.	Char
2	LID	Name of a LID process defined in the LID_CONTROLS section.	Char
3	Number	Number of replicate LID units deployed.	Integer
4	Area	Area of each replicate unit (ft2 or m2 if using metric units)	Float
5	Width	Width of the outflow face of each identical LID unit (in ft or m if using metric units). This parameter applies to roofs, pavement, trenches, and swales that use overland flow to convey surface runoff off of the unit. It can be set to 0 for other LID processes, such as bio-retention cells, rain gardens, and rain barrels that simply spill any excess captured runoff over their berms.	Float
6	InitSat	The percent to which the LID’s soil, storage, and drain mat zones are initially filled with water. For soil zones 0 % saturation corresponds to the wilting point moisture content while 100 % saturation has the moisture content equal to the porosity.	Float
7	FromImp	The percent of the impervious portion of the subcatchment’s non-LID area whose runoff is treated by the LID practice. (E.g., if rain barrels are used to capture roof runoff and roofs represent 60% of the impervious area, then the impervious area treated is 60%). If the LID unit treats only direct rainfall, such as with a green roof, then this value should be 0. If the LID takes up the entire subcatchment then this field is ignored.	Float
8	ToPerv	A value of 1 indicates that the surface and drain flow from the LID unit should be routed back onto the pervious area of the subcatchment that contains it. This would be a common choice to make for rain barrels, rooftop disconnection, and possibly green roofs. The default value is 0.	Float
9	RptFile	Optional name of a file to which detailed time series results for the LID will be written. Enclose the name in double quotes if it contains spaces and include its full path if it resides in a different directory than the SWMM input file. Use ’*’ if not applicable and an entry for DrainTo or FromPerv follows	Char
10	DrainTo	Optional name of subcatchment or node that receives flow from the unit’s drain line, if different from the outlet of the subcatchment that the LID is placed in. Use ’*’ if not applicable and an entry for FromPerv follows.	Char
11	FromPerv	Optional percent of the pervious portion of the subcatchment’s non-LID area whose runoff is treated by the LID practice. The default value is 0.	Float

Table L.20: Conduits

No.	Default GIS Attribute Name	Description	Type
1	Name	Name assigned to conduit link.	Char
2	From Node	Name of the conduit’s upstream node.	Char
3	To Node	Name of the conduit’s downstream node.	Char
4	Length	Conduit length (ft or m if using metric units).	Float
5	Roughness	Manning’s roughness coefficient (n).	Float
6	InOffset	Offset of the conduit’s upstream end above the invert of its upstream node (ft or m if using metric units).	Float
7	OutOffset	Offset of the conduit’s downstream end above the invert of its downstream node (ft or m if using metric units).	Float
8	InitFlow	Flow in the conduit at the start of the simulation (flow units) (default is 0).	Float
9	MaxFlow	Maximum flow allowed in the conduit (flow units) (default is no limit).	Float
10	xsec_XsecType	A cross-section shape, the available shapes include: Circular, Force_main, Filled_circular2, Rect_closed, Rect_open, Trapezoidal, Triangular, Horiz_ellipse, Vert_ellipse, Arch, Parabolic, Power, Rect_triangular, Rect_round, Modbaskethandle, Egg, Horseshoe, Gothic, Catenary, Semielliptical, Baskethandle, Semicircular, Custom.	Char
11	xsec_Geom1	Circular, Force_main, Filled_circular2: Diameter (ft or m if using metric units) All other shapes: Full height of the cross-section (ft or m if using metric units)	Float
12	xsec_Geom2	Modbaskethandle and Trapezoidal: Base Width Arch, Horiz_ellipse and Vert_ellipse: Max. Width Force_main: Roughness Filled_circular2: Sediment depth Custom: Shape curve Parabolic, Power, Rect_closed, Rect_open, Rect_round, Rect_triangular, Triangular: Top width All other shapes: Not used	Float
13	xsec_Geom3	Rect_Round: Bottom Radius Power: Exponent Trapezoidal: Left Slope Vert_ellipse and Horiz_ellipse: Size Code Arch: Size Code ModBasketHandle: Top Radius Rect_Triangular: Triangle Height All other shapes: Not used	Float
14	xsec_Geom4	Trapezoidal: Right slope All other shapes: Not used	Float
15	xsec_Barrels	Number of barrels (i.e., number of parallel pipes of equal size, slope, and roughness) associated with a conduit (default is 1).	Integer
16	xsec_Culvert	Code number from Table A.10 for the conduit’s inlet geometry if it is a culvert subject to possible inlet flow control (leave blank otherwise).	Char
17	xsec_Curve	Name of a Shape Curve in the CURVES section that defines how cross-section width varies with depth.	Char
18	xsec_Tsect	Name of an entry in the TRANSECTS section that describes the cross-section geometry of an irregular channel.	Char
19	xsec_Street	Name of an entry in the STREETS section that describes the cross-section geometry of a street.	Char
20	losses_Kentry	Minor head loss coefficient at the conduit’s entrance.	Float
21	losses_Kexit	Minor head loss coefficient at the conduit’s exit.	Float
22	losses_Kavg	Average minor head loss coefficient across the length of the conduit.	Float
23	losses_Flap	YES if the conduit has a flap valve that prevents back flow, NO otherwise. (Default is NO).	Char
24	losses_Seepage	Rate of seepage loss into the surrounding soil (in/hr or mm/hr if using metric units). (Default is 0.)	Float

Table L.21: Controls

No.	Default GIS Attribute Name	Description	Type
1	Text	Determines how pumps and regulators will be adjusted based on simulation time or conditions at specific nodes and links.	Char

Table L.22: Orifices

No.	Default GIS Attribute Name	Description	Type
1	Name	Name assigned to orifice link.	Char
2	From Node	Name of the orifice’s inlet node.	Char
3	To Node	Name of the orifice’s outlet node.	Char
4	Type	The type of orifice - either SIDE if oriented in a vertical plane or BOTTOM if oriented in a horizontal plane.	Char
5	Offset	Amount that a Side Orifice’s bottom or the position of a Bottom Orifice is offset above the invert of inlet node (ft or m, expressed as either a depth or as an elevation, depending on the LINK_OFFSETS option setting).	Float
6	Qcoeff	Discharge coefficient (unitless).	Float
7	Gated	YES if a flap gate prevents reverse flow, NO if not (default is NO).	Char
8	CloseTime	Time in decimal hours to open a fully closed orifice (or close a fully open one). Use 0 if the orifice can open/close instantaneously.	Float
9	xsec_XsecType	The only allowable shapes are CIRCULAR and RECT_CLOSED (closed rectangular).	Char
10	xsec_Geom1	Circular: Diameter (ft or m) Rect_Closed: Full height of the cross-section (ft or m if using metric units)	Float
11	xsec_Geom2	Circular: Not used Rect_closed: Top width	Float
12	xsec_Geom3	Not used	Float
13	xsec_Geom4	Not used	Float
14	xsec_Barrels	Number of barrels (i.e., number of parallel pipes of equal size, slope, and roughness) associated with a conduit (default is 1).	Integer
15	xsec_Culvert	Code number from Table A.10 for the conduit’s inlet geometry if it is a culvert subject to possible inlet flow control (leave blank otherwise).	Char
16	xsec_Curve	Name of a Shape Curve in the CURVES section that defines how cross-section width varies with depth.	Char
17	xsec_Tsect	Name of an entry in the TRANSECTS section that describes the cross-section geometry of an irregular channel.	Char
18	xsec_Street	Name of an entry in the STREETS section that describes the cross-section geometry of a street.	Char

Table L.23: Outlets

No.	Default GIS Attribute Name	Description	Type
1	Name	Name assigned to outlet link.	Char
2	From Node	Name of the outlet’s inlet node.	Char
3	To Node	Name of the outlet’s outlet node.	Char
4	Offset	Amount that the outlet is offset above the invert of its inlet node (ft or m, expressed as either a depth or as an elevation, depending on the LINK_OFFSETS option setting).	Float
5	Type	TABULAR/DEPTH, TABULAR/HEAD, FUNCTIONAL/DEPTH, FUNCTIONAL/HEAD	Char
6	QCurve	Name of the rating curve listed in the CURVES section that describes outflow rate (flow units) as a function of: - water depth above the offset elevation at the inlet node (ft or m if using metric units) for a TABULAR/DEPTH outlet. - head difference (ft or m) between the inlet and outflow nodes for a TABULAR/HEAD outlet.	Char
7	C1	Coefficient of a power function that relates outflow to: - water depth (ft or m if using metric units) above the offset elevation at the inlet node for a FUNCTIONAL/DEPTH outlet. - head difference  (ft or m if using metric units) between the inlet and outflow nodes for a FUNCTIONAL/HEAD outlet.	Float
8	C2	Exponent of a power function that relates outflow to: - water depth (ft or m if using metric units) above the offset elevation at the inlet node for a FUNCTIONAL/DEPTH outlet. - head difference  (ft or m if using metric units) between the inlet and outflow nodes for a FUNCTIONAL/HEAD outlet.	Float
9	Gated	YES if a flap gate prevents reverse flow, NO if not (default is NO).	Char

Table L.24: Pumps

No.	Default GIS Attribute Name	Description	Type
1	Name	Name assigned to pump link.	Char
2	From Node	Name of the pump’s inlet node.	Char
3	To Node	Name of the pump’s outlet node.	Char
4	Pcurve	Name of a pump curve listed in the CURVES section of the input. A pump curve describes the relation between a pump’s flow rate and conditions at its inlet and outlet nodes. The following types of pump curves are supported: Type1: An off-line pump with a wet well where flow increases incrementally with available wet well volume. Type2: An in-line pump where flow increases incrementally with inlet node depth. Type3: An in-line pump where flow varies continuously with head difference between the inlet and outlet nodes. Type4: A variable speed in-line pump where flow varies continuously with inlet node depth. Type5: A variable speed version of the Type3 pump where the head v. flow curve shifts position as the speed setting changes. Ideal: A transfer pump that does not require a pump curve and is used mainly for preliminary design. Its flow rate equals the inflow rate to its inlet node no matter what the head difference is between its inlet and outlet nodes. Use an asterisk (*) as the value for Pcurve.	Char
5	Status	Pump’s status at the start of the simulation (either ON or OFF; default is ON).	Char
6	Startup	Depth at the inlet node when the pump turns on (ft or m if using metric units) (default is 0).	Float
7	Shutoff	Depth at inlet node when the pump shuts off (ft or m if using metric units) (default is 0).	Float

Table L.25: Streets

No.	Default GIS Attribute Name	Description	Type
1	Name	Name assigned to the street cross-section.	Char
2	Tcrown	Distance from street’s curb to its crown (ft or m if using metric units).	Float
3	Hcurb	Curb height (ft or m if using metric units).	Float
4	Sx	Street cross slope (%).	Float
5	nRoad	Manning’s roughness coefficient (n) of the road surface	Float
6	a	Gutter depression height (in or mm if using metric units) (default = 0).	Float
7	W	Depressed gutter width (ft or m if using metric units) (default = 0).	Float
8	Sides	1 for single sided street or 2 for two-sided street (default = 2).	Integer
9	Tback	Street backing width (ft or m if using metric units) (default = 0).	Float
10	Sback	Street backing slope (%) (default = 0).	Float
11	nBack	Street backing Manning’s roughness coefficient (n) (default = 0).	Float

Table L.26: Transects

No.	Default GIS Attribute Name	Description	Type
1	Name	Name assigned to the transect.	Char
2	Xleft	Station position which ends the left overbank portion of the channel (ft or m if using metric units).	Char
3	Xright	Station position which begins the right overbank portion of the channel (ft or m if using metric units).	Char
4	Lfactor	Meander modifier that represents the ratio of the length of a meandering main channel to the length of the overbank area that surrounds it (use 0 if not applicable).	Char
5	Wfactor	Factor by which distances between stations should be multiplied to increase (or decrease) the width of the channel (enter 0 if not applicable).	Char
6	Eoffset	Amount to be added (or subtracted) from the elevation of each station (ft or m if using metric units).	Char
7	Nleft	Manning’s roughness coefficient (n) of right overbank portion of channel (use 0 if no change from previous NC line).	Char
8	Nright	Manning’s roughness coefficient (n) of right overbank portion of channel (use 0 if no change from previous NC line.	Char
9	Nchan1	Manning’s roughness coefficient (n) of main channel portion of channel (use 0 if no change from previous NC line.	Char

Table L.27: Transects Coordinates

No.	Default GIS Attribute Name	Description	Type
1	Name	Name assigned to the transect.	Char
2	Elev	Elevation of the channel bottom at a cross-section station relative to some fixed reference (ft or m if using metric units).	Float
3	Station	Distance of a cross-section station from some fixed reference (ft or m if using metric units).	Float

Table L.28: Weirs

No.	Default GIS Attribute Name	Description	Type
1	Name	Name assigned to weir link.	Char
2	From Node	Name of the weir’s inlet node.	Char
3	To Node	Name of the weir’s outlet node.	Char
4	Type	TRANSVERSE, SIDEFLOW, V-NOTCH, TRAPEZOIDAL or ROADWAY.	Char
5	CrestHt	Amount that the weir’s opening is offset above the invert of inlet node (ft or m if using metric units, expressed as either a depth or as an elevation, depending on the LINK_OFFSETS option setting).	Float
6	Cd	Weir discharge coefficient (for CFS if using US flow units or CMS if using metric flow units).	Float
7	Gated	YES if a flap gate prevents reverse flow, NO if not (default is NO).	Char
8	EC	Number of end contractions for a TRANSVERSE or TRAPEZOIDAL weir (default is 0).	Char
9	Cd2	Discharge coefficient for the triangular ends of a TRAPEZOIDAL weir (for CFS if using US flow units or CMS if using metric flow units) (default is the value of Cd).	Float
10	Sur	YES if the weir can surcharge (have an upstream water level higher than the height of the weir’s opening); NO if it cannot (default is YES).	Char
11	Road_Width	Applies only to ROADWAY weirs. Width of road lanes and shoulders for a ROADWAY weir (ft or m if using metric units).	Float
12	Road_Surf	Applies only to ROADWAY weirs. Type of road surface for a ROADWAY weir: PAVED or GRAVEL.	Char
13	xsec_XsecType	A cross-section shape. The following shapes must be used with each type of weir: Transverse: RECT_OPEN Sideflow: RECT_OPEN V-Notch: TRIANGULAR Trapezoidal: TRAPEZOIDAL Roadway: RECT_OPEN The ROADWAY weir is a broad crested rectangular weir used model roadway crossings usually in conjunction with culvert-type conduits. It uses the FHWA HDS-5 method to determine a discharge coefficient as a function of flow depth and roadway width and surface. If no roadway data are provided then the weir behaves as a TRANSVERSE weir with Cd as its discharge coefficient. Note that if roadway data are provided, then values for the other optional weir parameters (NO for Gated, 0 for EC, 0 for Cd2, and NO for Sur) must be entered even though they do not apply to ROADWAY weirs.	Char
14	xsec_Geom1	Full height of the cross-section (ft or m if using metric units)	Float
15	xsec_Geom2	Trapezoidal: Base Width Rect_open and Triangular: Top width	Float
16	xsec_Geom3	Trapezoidal: Left Slope Rect_open and Triangular: Not used	Float
17	xsec_Geom4	Trapezoidal: Right slope All other shapes: Not used	Float
18	xsec_Barrels	Number of barrels (i.e., number of parallel pipes of equal size, slope, and roughness) associated with a conduit (default is 1).	Integer
19	xsec_Culvert	Code number from Table A.10 for the conduit’s inlet geometry if it is a culvert subject to possible inlet flow control (leave blank otherwise).	Char
20	xsec_Curve	Name of a Shape Curve in the CURVES section that defines how cross-section width varies with depth.	Char
21	xsec_Tsect	Name of an entry in the TRANSECTS section that describes the cross-section geometry of an irregular channel.	Char
22	xsec_Street	Name of an entry in the STREETS section that describes the cross-section geometry of a street.	Char

Table L.29: Dividers

No.	Default GIS Attribute Name	Description	Type
1	Name	Name assigned to divider node.	Char
2	Elev	Node’s invert elevation (ft or m if using metric units).	Float
3	DivLink	Name of the link to which flow is diverted.	Char
4	Type	OVERFLOW: CUTOFF: TABULAR: WEIR:	Char
5	Qmin	CUTOFF and WEIR: flow at which diversion begins (flow units). OVERFLOW and TABULAR: Not Used.	Float
6	Dcurve	TABULAR: name of a curve that relates diverted flow to total flow. OVERFLOW, CUTOFF and WEIR: Not Used.	Float
7	Ht	WEIR: height of a WEIR divider (ft or m). OVERFLOW, CUTOFF and TABULAR: Not Used.	Float
8	Cd	WEIR: discharge coefficient for a WEIR divider. OVERFLOW, CUTOFF and TABULAR: Not Used.	Float
9	Ymax	OVERFLOW, CUTOFF, TABULAR and WEIR: depth from the ground to the node’s invert elevation (ft or m if using metric units) (default is 0).	Float
10	Y0	OVERFLOW, CUTOFF, TABULAR and WEIR: water depth at the start of the simulation (ft or m if using metric units) (default is 0).	Float
11	Ysur	OVERFLOW, CUTOFF, TABULAR and WEIR: maximum additional pressure head above the ground elevation that the node can sustain under surcharge conditions (ft or m if using metric units) (default is 0).	Float
12	Apond	OVERFLOW, CUTOFF, TABULAR and WEIR: area subjected to surface ponding once water depth exceeds Ymax + Ysur  (ft2 or m2 if using metric units) (default is 0).	Float

Table L.30: DWF

No.	Default GIS Attribute Name	Description	Type
1	Node	Name of a node where dry weather flow enters.	Char
2	Type	Keyword FLOW for flow or a pollutant name for a quality constituent.	Char
3	Base	Average baseline value for corresponding constituent  (flow or concentration units). The actual dry weather input will equal the product of the baseline value and any adjustment factors supplied by the specified patterns. If not supplied, an adjustment factor defaults to 1.0.	Float
4	Pat1	Name of first time pattern appearing in the PATTERNS section. The patterns can be any combination of monthly, daily, hourly and weekend hourly patterns, listed in any order. See the PATTERNS section for more details.	Char
5	Pat2	Name of second time pattern appearing in the PATTERNS section. The patterns can be any combination of monthly, daily, hourly and weekend hourly patterns, listed in any order. See the PATTERNS section for more details.	Char
6	Pat3	Name of third time pattern appearing in the PATTERNS section. The patterns can be any combination of monthly, daily, hourly and weekend hourly patterns, listed in any order. See the PATTERNS section for more details.	Char
7	Pat4	Name of fourth time pattern appearing in the PATTERNS section. The patterns can be any combination of monthly, daily, hourly and weekend hourly patterns, listed in any order. See the PATTERNS section for more details.	Char

Table L.31: Junctions

No.	Default GIS Attribute Name	Description	Type
1	Name	Name assigned to junction node.	Char
2	Elev	Elevation of the junction’s invert (ft or m if using metric units).	Float
3	Ymax	Depth from ground to invert elevation (ft or m if using metric units). Default is 0. If Ymax is 0 then SWMM sets the junction’s maximum depth to the distance from its invert to the top of the highest connecting link.	Float
4	Y0	Water depth at the start of the simulation (ft or m if using metric units). Default is 0.	Float
5	Ysur	Maximum additional pressure head above the ground elevation that the junction can sustain under surcharge conditions (ft or m if using metric units). Default is 0. If the junction is part of a force main section of the system then set Ysur to the maximum pressure that the system can sustain.	Char
6	Apond	Area subjected to surface ponding once water depth exceeds Ymax + Ysur (ft2 or m2 if using metric units). Default is 0. Surface ponding can only occur when Apond is non-zero and the ALLOW_PONDING analysis option is turned on.	Float

Table L.32: Outfalls

No.	Default GIS Attribute Name	Description	Type
1	Name	Name assigned to outfall node.	Char
2	Elev	Node’s invert elevation (ft or m if using metric units).	Float
3	Type	Use either FREE, NORMAL, FIXED, TIDAL or TIMESERIES.	Char
4	Stage	FIXED: Elevation of a fixed stage outfall (ft or m). FREE, NORMAL, TIDAL and TIMESERIES: Not Used.	Char
5	Tcurve	TIDAL: Name of a curve in the CURVES section containing tidal height (i.e., outfall stage) v. hour of day over a complete tidal cycle. FREE, NORMAL, FIXED and TIMESERIES: Not Used.	Char
6	Tseries	TIMESERIES: Name of a time series in TIMESERIES section that describes how outfall stage varies with time. FREE, NORMAL, FIXED and TIDAL: Not Used.	Char
7	Gated	YES or NO depending on whether a flap gate is present that prevents reverse flow. The default is NO.	Char
8	RouteTo	Optional. Name of a subcatchment that receives the outfall’s discharge. The default is not to route the outfall’s discharge.	Char

Table L.33: Storage

No.	Default GIS Attribute Name	Description	Type
1	Name	Name assigned to storage node.	Char
2	Elev	Node’s invert elevation (ft or m if using metric units).	Float
3	Ymax	Water depth when the storage node is full (ft or m if using metric units).	Float
4	Y0	Water depth at the start of the simulation (ft or m if using metric units).	Float
5	TYPE	TABULAR: FUNCTIONAL: CYLINDRICAL: CONICAL: PARABOLOID: PYRAMIDAL:	Char
6	Acurve	Name of a curve in the CURVES section that relates surface area (ft2 or m2 if using metric units) to depth (ft or m if using metric units) for TABULAR geometry.	Char
7	A1	Coefficient of a FUNCTIONAL relation between surface area and depth. Where Area = A0 + A1*DepthA2.	Float
8	A2	Exponent of a FUNCTIONAL relation between surface area and depth.	Float
9	A0	Constant of a FUNCTIONAL relation between surface area and depth.	Float
10	L	CYLINDRICAL: major axis length CONICAL: major axis length of base PARABOLOID: major axis length at full height PYRAMIDAL: base length	Float
11	W	CYLINDRICAL: major axis width CONICAL: major axis width of base PARABOLOID: minor axis width at full height PYRAMIDAL: base width	Float
12	Z	CYLINDRICAL: Not Used. CONICAL: side slope (run/rise) PARABOLOID: full height PYRAMIDAL: side slope (run/rise)	Float
13	Ysur	Maximum additional pressure head above full depth that a closed storage unit can sustain under surcharge conditions (ft or m if using metric units) (default is 0).	Float
14	Fevap	Fraction of potential evaporation from the storage unit’s water surface realized (default is 0).	Float
15	Psi	Optional seepage parameters for soil surrounding the storage unit. Suction head (inches or mm if using metric units).	Float
16	Ksat	Optional seepage parameters for soil surrounding the storage unit. Saturated hydraulic conductivity  (in/hr or mm/hr if using metric units).	Float
17	IMD	Optional seepage parameters for soil surrounding the storage unit. Initial moisture deficit (porosity minus moisture content) (fraction).	Float

Table L.34: Files

No.	Default GIS Attribute Name	Description	Type
1	Operation	Set if the interface file is to be used or saved by a run: USE SAVE	Char
2	Filetype	The different types of interface files that are currently available include: RAINFALL: rainfall interface file (USE / SAVE operation) RUNOFF: runoff interface file (USE / SAVE operation) HOTSTART: hot start file (USE / SAVE operation) RDII: RDII interface file (USE / SAVE operation) INFLOWS: routing interface files (USE operation only) OUTFLOWS: routing interface files (SAVE operation only) Rainfall, Runoff, and RDII files can either be used or saved in a run, but not both. A run can both use and save a Hot Start file (with different names).	Char
3	Filename	The name of an interface file. Enclose the external file name in double quotes if it contains spaces and include its full path if it resides in a different directory than the SWMM input file.	Char

Table L.35: Options

No.	Default GIS Attribute Name	Description	Type
1	Option	FLOW_UNITS makes a choice of flow units. Selecting a US flow unit means that all other quantities will be expressed in US customary units, while choosing a metric flow unit will force all quantities to be expressed in SI metric units. (Exceptions are pollutant concentration and Manning’s roughness coefficient (n) which are always in metric units). The default is CFS. INFILTRATION selects a model for computing infiltration of rainfall into the upper soil zone of subcatchments. The default model is HORTON. FLOW_ROUTING determines which method is used to route flows through the drainage system. STEADY refers to sequential steady state routing (i.e. hydrograph translation), KINWAVE to kinematic wave routing, DYNWAVE to dynamic wave routing. The default routing method is DYNWAVE. LINK_OFFSETS determines the convention used to specify the position of a link offset above the invert of its connecting node. DEPTH indicates that offsets are expressed as the distance between the node invert and the link while ELEVATION indicates that the absolute elevation of the offset is used. The default is DEPTH. FORCE_MAIN_EQUATION establishes whether the Hazen-Williams (H-W) or the Darcy-Weisbach (D-W) equation will be used to compute friction losses for pressurized flow in conduits that have been assigned a Circular Force Main cross-section shape. The default is H-W. IGNORE_RAINFALL is set to YES if all rainfall data and runoff calculations should be ignored. In this case SWMM only performs flow and pollutant routing based on user-supplied direct and dry weather inflows. The default is NO. IGNORE_SNOWMELT is set to YES if snowmelt calculations should be ignored when a project file contains snow pack objects. The default is NO. IGNORE_GROUNDWATER is set to YES if groundwater calculations should be ignored when a project file contains aquifer objects. The default is NO. IGNORE_RDII is set to YES if rainfall dependent inflow/infiltration should be ignored when RDII unit hydrographs and RDII inflows have been supplied to a project file. The default is NO. IGNORE_ROUTING is set to YES if only runoff should be computed even if the project contains drainage system links and nodes. The default is NO. IGNORE_QUALITY is set to YES if pollutant washoff, routing, and treatment should be ignored in a project that has pollutants defined. The default is NO. ALLOW_PONDING determines whether excess water is allowed to collect atop nodes and be re-introduced into the system as conditions permit. The default is NO ponding. In order for ponding to actually occur at a particular node, a non-zero value for its Ponded Area attribute must be used. SKIP_STEADY_STATE should be set to YES if flow routing computations should be skipped during steady state periods of a simulation during which the last set of computed flows will be used. A time step is considered to be in steady state if the percent difference between total system inflow and total system outflow is below the SYS_FLOW_TOL and the percent difference between current and previous lateral inflows are below the LAT_FLOW_TOL. The default for this option is NO. SYS_FLOW_TOL is the maximum percent difference between total system inflow and total system outflow which can occur in order for the SKIP_STEADY_STATE option to take effect. The default is 5 percent. LAT_FLOW_TOL is the maximum percent difference between the current and previous lateral inflow at all nodes in the conveyance system in order for the SKIP_STEADY_STATE option to take effect. The default is 5 percent. START_DATE is the date when the simulation begins. If not supplied, a date of 2004-01-01 is used. START_TIME is the time of day on the starting date when the simulation begins. The default is 12 midnight (0:00:00). END_DATE is the date when the simulation is to end. The default is the start date. END_TIME is the time of day on the ending date when the simulation will end. The default is 24:00:00. REPORT_START_DATE is the date when reporting of results is to begin. The default is the simulation start date. REPORT_START_TIME is the time of day on the report starting date when reporting is to begin. The default is the simulation start time of day. SWEEP_START is the day of the year (month/day) when street sweeping operations begin. The default is 1/1. SWEEP_END is the day of the year (month/day) when street sweeping operations end. The default is 12/31. DRY_DAYS is the number of days with no rainfall prior to the start of the simulation. The default is 0. REPORT_STEP is the time interval for reporting of computed results. The default is 0:15:00. WET_STEP is the time step length used to compute runoff from subcatchments during periods of rainfall or when ponded water still remains on the surface. The default is 0:05:00. DRY_STEP is the time step length used for runoff computations (consisting essentially of pollutant buildup) during periods when there is no rainfall and no ponded water. The default is 1:00:00. ROUTING_STEP is the time step length in seconds used for routing flows and water quality constituents through the conveyance system. The default is 20 sec. This can be increased if dynamic wave routing is not used. Fractional values (e.g., 2.5) are permissible as are values entered in hours:minutes:seconds format. LENGTHENING_STEP is a time step, in seconds, used to lengthen conduits under dynamic wave routing, so that they meet the Courant stability criterion under full-flow conditions (i.e., the travel time of a wave will not be smaller than the specified conduit lengthening time step). As this value is decreased, fewer conduits will require lengthening. A value of 0 (the default) means that no conduits will be lengthened. VARIABLE_STEP is a safety factor applied to a variable time step computed for each time period under dynamic wave flow routing. The variable time step is computed so as to satisfy the Courant stability criterion for each conduit and yet not exceed the ROUTING_STEP value. If the safety factor is 0 (the default), then no variable time step is used. MINIMUM_STEP is the smallest time step allowed when variable time steps are used for dynamic wave flow routing. The default value is 0.5 seconds. INERTIAL_DAMPING indicates how the inertial terms in the Saint Venant momentum equation will be handled under dynamic wave flow routing. Choosing NONE maintains these terms at their full value under all conditions. Selecting PARTIAL (the default) will reduce the terms as flow comes closer to being critical (and ignores them when flow is supercritical). Choosing FULL will drop the terms altogether. NORMAL_FLOW_LIMITED specifies which condition is checked to determine if flow in a conduit is supercritical and should thus be limited to the normal flow. Use SLOPE to check if the water surface slope is greater than the conduit slope, FROUDE to check if the Froude number is greater than 1.0, BOTH to check both conditions or NONE if no checks are made. The default is BOTH. SURCHARGE_METHOD selects which method will be used to handle surcharge conditions. The EXTRAN option uses a variation of the Surcharge Algorithm from previous versions of SWMM to update nodal heads when all connecting links become full. The SLOT option uses a Preissmann Slot to add a small amount of virtual top surface width to full flowing pipes so that SWMM’s normal procedure for updating nodal heads can continue to be used. The default is EXTRAN. MIN_SURFAREA is a minimum surface area used at nodes when computing changes in water depth under dynamic wave routing. If 0 is entered, then the default value of 12.566 ft2 (1.167 m2) (i.e., the area of a 4-ft diameter manhole) is used. MIN_SLOPE is the minimum value allowed for a conduit’s slope (%). If zero (the default) then no minimum is imposed (although SWMM uses a lower limit on elevation drop of 0.001 ft (0.00035 m) when computing a conduit slope). MAX_TRIALS is the maximum number of trials allowed during a time step to reach convergence when updating hydraulic heads at the conveyance system’s nodes. The default value is 8. HEAD_TOLERANCE is the difference in computed head at each node between successive trials below which the flow solution for the current time step is assumed to have converged. The default tolerance is 0.005 ft (0.0015 m). THREADS is the number of parallel computing threads to use for dynamic wave flow routing on machines equipped with multi-core processors. The default is 1.	Char
2	Value	FLOW_UNITS: CFS / GPM / MGD / CMS / LPS / MLD INFILTRATION: HORTON / MODIFIED_HORTON / GREEN_AMPT / MODIFIED_GREEN_AMPT / CURVE_NUMBER FLOW_ROUTING: STEADY / KINWAVE / DYNWAVE LINK_OFFSETS: DEPTH / ELEVATION FORCE_MAIN_EQUATION: H-W / D-W IGNORE_RAINFALL: YES / NO IGNORE_SNOWMELT: YES / NO IGNORE_GROUNDWATER: YES / NO IGNORE_RDII: YES / NO IGNORE_ROUTING: YES / NO IGNORE_QUALITY: YES / NO ALLOW_PONDING: YES / NO SKIP_STEADY_STATE: YES / NO SYS_FLOW_TOL: value LAT_FLOW_TOL: value START_DATE: yyyy-mm-dd (default) or month/day/year START_TIME: hours:minutes END_DATE: yyyy-mm-dd (default) or month/day/year END_TIME: hours:minutes REPORT_START_DATE: yyyy-mm-dd (default) or month/day/year REPORT_START_TIME: hours:minutes SWEEP_START: month/day SWEEP_END: month/day DRY_DAYS: days REPORT_STEP: hours:minutes:seconds WET_STEP: hours:minutes:seconds DRY_STEP: hours:minutes:seconds ROUTING_STEP: seconds LENGTHENING_STEP: seconds VARIABLE_STEP: value MINIMUM_STEP: seconds INERTIAL_DAMPING: NONE / PARTIAL / FULL NORMAL_FLOW_LIMITED: SLOPE / FROUDE / BOTH / NONE SURCHARGE_METHOD: EXTRAN / SLOT MIN_SURFAREA: value MIN_SLOPE: value MAX_TRIALS: value HEAD_TOLERANCE: value THREADS: value	Char

Table L.36: Report

No.	Default GIS Attribute Name	Description	Type
1	Format	INPUT specifies whether or not a summary of the input data should be provided in the output report. The default is NO. CONTINUITY specifies whether continuity checks should be reported or not. The default is YES. FLOWSTATS specifies whether summary flow statistics should be reported or not. The default is YES. CONTROLS specifies whether all control actions taken during a simulation should be listed or not. The default is NO. SUBCATCHMENTS gives a list of subcatchments whose results are to be reported. The default is NONE. NODES gives a list of nodes whose results are to be reported. The default is NONE. LINKS gives a list of links whose results are to be reported. The default is NONE. LID specifies that the LID control Name in subcatchment Subcatch should have a detailed performance report for it written to file Fname. The SUBCATCHMENTS, NODES, LINKS, and LID lines can be repeated multiple times.	Char
2	Value	INPUT: YES / NO CONTINUITY: YES / NO FLOWSTATS: YES / NO CONTROLS: YES / NO SUBCATCHMENTS: ALL / NONE / NODES: ALL / NONE / LINKS: ALL / NONE / LID: Name Subcatch Fname	Char

Table L.37: Title

No.	Default GIS Attribute Name	Description	Type
1	Title	Any number of lines may be entered. The first line will be used as a page header in the output report.	Char

Table L.38: Subcatchments

No.	Default GIS Attribute Name	Description	Type
1	Name	Name assigned to the subcatchment.	Char
2	Rain Gage	Name of a rain gage in the RAINGAGES section assigned to the subcatchment.	Char
3	Outlet	Name of the node or subcatchment that receives runoff from the subcatchment.	Char
4	Area	Area of the subcatchment (acres or hectares if using metric units).	Float
5	PctImperv	Percentage of the subcatchment’s area that is impervious.	Float
6	Width	Characteristic width of the subcatchment (ft or m, if using metric units).	Float
7	PctSlope	The subcatchment’s slope (percent).	Float
8	CurbLen	Total curb length (any length units) used to describe pollutant buildup. Use 0 if not applicable.	Float
9	SnowPack	Optional name of a snow pack object (from the SNOWPACKS section) that characterizes snow accumulation and melting over the subcatchment.	Char
10	Subareas_Nimp	Manning’s coefficient (n) for overland flow over the impervious sub-area.	Float
11	Subareas_Nperv	Manning’s coefficient (n) for overland flow over the pervious sub-area.	Float
12	Subareas_Simp	Depression storage for the impervious sub-area (inches or mm, if using metric units).	Float
13	Subareas_Sperv	Depression storage for the pervious sub-area (inches or mm, if using metric units).	Float
14	Subareas_PctZero	Percent of impervious area with no depression storage.	Float
15	Subareas_RouteTo	IMPERVIOUS if pervious area runoff runs onto impervious area, PERVIOUS if impervious runoff runs onto pervious area, or OUTLET if both areas drain to the subcatchment’s outlet (default = OUTLET).	Char
16	Subareas_PctRouted	Percent of runoff routed from one type of area to another (default = 100).	Float
17	Infiltration_p1	HORTON and MODIFIED_HORTON: maximum infiltration rate on the Horton curve (in/hr or mm/hr). GREEN-AMPT and MODIFIED_GREEN_AMPT: soil capillary suction (in or mm if using metric units). CURVE_NUMBER: SCS Curve Number.	Float
18	Infiltration_p2	HORTON and MODIFIED_HORTON: minimum infiltration rate on the Horton curve (in/hr or mm/hr if using metric units). GREEN-AMPT and MODIFIED_GREEN_AMPT: soil saturated hydraulic conductivity (in/hr or mm/hr if using metric units). CURVE_NUMBER: no longer used.	Float
19	Infiltration_p3	HORTON and MODIFIED_HORTON: decay rate constant of the Horton curve (1/hr). GREEN-AMPT and MODIFIED_GREEN_AMPT: initial soil moisture deficit (porosity minus moisture content) (fraction). CURVE_NUMBER: time it takes for a fully saturated soil to dry (days).	Float
20	Infiltration_p4	HORTON and MODIFIED_HORTON: time it takes for a fully saturated soil to dry (days). GREEN-AMPT, MODIFIED_GREEN_AMPT and CURVE_NUMBER: Not Used.	Float
21	Infiltration_p5	HORTON and MODIFIED_HORTON: maximum infiltration volume possible (0 if not applicable) (in or mm if using metric units). GREEN-AMPT, MODIFIED_GREEN_AMPT and CURVE_NUMBER: Not Used.	Float
22	Infiltration_Method	Either HORTON, MODIFIED_HORTON, GREEN_AMPT, MODIFIED_GREEN_AMPT, or CURVE_NUMBER. If not specified then the infiltration method supplied in the OPTIONS section is used.	Char

Table L.39: Buildup

No.	Default GIS Attribute Name	Description	Type
1	Landuse	Land use name.	Char
2	Pollutant	Pollutant name.	Char
3	FuncType	Buildup function type. POW (Power): Min(C1, C2*tC3) EXP (Exponential): C1(1-exp(-C2t)) SAT (Saturation): (C1*t)/(C3+t) EXT (External): C1 is the maximum possible buildup (mass per area or curb length), C2 is a scaling factor, and C3 is the name of a Time Series that contains buildup rates (as mass per area or curb length per day) as a function of time.	Char
4	C1	Buildup function parameters (see FuncType).	Float
5	C2	Buildup function parameters (see FuncType).	Float
6	C3	Buildup function parameters (see FuncType).	Float
7	PerUnit	AREA if buildup is per unit area, CURBLENGTH if per length of curb.	Char

Table L.40: Coverages

No.	Default GIS Attribute Name	Description	Type
1	Subcatchment	Subcatchment name.	Char
2	Landuse	Land use name.	Char
3	Percent	Percent of the subcatchment’s area covered by the land use	Float

Table L.41: Landuses

No.	Default GIS Attribute Name	Description	Type
1	Name	Land use name.	Char
2	SweepIntervalDays	Days between street sweeping.	Float
3	AvailabilityFract	Fraction of pollutant buildup available for removal by street sweeping.	Float
4	LastSweepDays	Days since last sweeping at the start of the simulation.	Float

Table L.42: Loadings

No.	Default GIS Attribute Name	Description	Type
1	Subcatchment	Name of a subcatchment.	Char
2	Landuse	Name of a pollutant.	Char
3	Percent	Initial buildup of the pollutant (lbs/acre or kg/hectare). If an initial buildup is not specified for a pollutant, then its initial buildup is computed by applying the DRY_DAYS option (specified in the OPTIONS section) to the pollutant’s buildup function for each land use in the subcatchment.	Float

Table L.43: Pollutants

No.	Default GIS Attribute Name	Description	Type
1	Name	Name assigned to a pollutant. Note, FLOW is a reserved word and cannot be used to name a pollutant.	Char
2	Units	Concentration units (MG/L for milligrams per liter, UG/L for micrograms per liter, or #/L for direct count per liter).	Char
3	Crain	Concentration of the pollutant in rainfall (concentration units).	Float
4	Cgw	Concentration of the pollutant in groundwater (concentration units).	Float
5	cii	Concentration of the pollutant in inflow/infiltration (concentration units).	Float
6	Kdecay	First-order decay coefficient (1/days).	Float
7	Sflag	YES if pollutant buildup occurs only when there is snow cover, NO otherwise (default is NO).	Char
8	CoPoll	Name of a co-pollutant (default is no co-pollutant designated by a *).	Char
9	CoFract	Fraction of the co-pollutant’s concentration (default is 0). When pollutant X has a co-pollutant Y, it means that fraction CoFract of pollutant Y’s runoff concentration is added to pollutant X’s runoff concentration when wash off from a subcatchment is computed.	Float
10	Cdwf	Pollutant concentration in dry weather flow (default is 0). If there is no co-pollutant but non-default values, then enter an asterisk (*) for the co-pollutant name. The dry weather flow concentration can be overridden for any specific node of the conveyance system by editing the node’s Inflows property (see the INFLOWS section).	Float
11	Cinit	Pollutant concentration throughout the conveyance system at the start of the simulation (default is 0). If there is no co-pollutant but non-default values, then enter an asterisk (*) for the co-pollutant name.	Float

Table L.44: Treatment

No.	Default GIS Attribute Name	Description	Type
1	Node	Name of the node where treatment occurs.	Char
2	Pollut	Name of pollutant receiving treatment.	Char
3	Result	Result computed by treatment function. Choices are: C  (function computes effluent concentration) R  (function computes fractional removal)	Char
4	Func	Mathematical function expressing treatment result in terms of pollutant concentrations, pollutant removals, and other standard variables. Treatment functions can be any well-formed mathematical expression involving: inlet pollutant concentrations (use the pollutant name to represent a concentration) removal of other pollutants (use R_ pre-pended to the pollutant name to represent removal) process variables which include: FLOW: for flow rate into node (user’s flow units) DEPTH: for water depth above node invert (ft or m) AREA: for node surface area (ft2 or m2) DT: for routing time step (seconds) HRT: for hydraulic residence time (hours)	Char

Table L.45: Washoff

No.	Default GIS Attribute Name	Description	Type
1	Landuse	Land use name.	Char
2	Pollutant	Pollutant name.	Char
3	FuncType	Washoff function type. Each washoff function expresses its results in different units. Available types: EXP (Exponential): C1(runoff)C2 (buildup) [Mass/hour]. Runoff variable is expressed in catchment depth per unit of time (in/hr or mm/hr if using metric units). RC (Rating Curve): C1(runoff)C2 [Mass/sec]. Runoff variable is in whatever flow units were specified in the OPTIONS section of the input file (e.g. CFS, CMS, etc.). EMC (Event Mean Concentration) C1 [Mass/Liter].	Char
4	C1	Washoff function coefficients. See FuncType. EXP: units are (in/hr)-C2 per hour or (mm/hr)-C2 per hour if using metric units. RC: units depend on the flow units employed. EMC: concentration units.	Float
5	C2	Washoff function coefficients. See FuncType.	Float
6	SweepRmv1	Street sweeping removal efficiency (percent).	Float
7	BmpRmv1	BMP removal efficiency (percent).	Float