openswmm_nodes.h File Reference

OpenSWMM Engine — Node C API. More...

#include "openswmm_engine.h"

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Typedefs
typedef enum SWMM_NodeType	SWMM_NodeType
	Node type classification.

Enumerations
enum	SWMM_NodeType {   SWMM_NODE_JUNCTION = 0 ,   SWMM_NODE_OUTFALL = 1 ,   SWMM_NODE_STORAGE = 2 ,   SWMM_NODE_DIVIDER = 3 }
	Node type classification. More...

Functions
SWMM_ENGINE_API int	swmm_node_count (SWMM_Engine engine)
	Get the total number of nodes in the model.
SWMM_ENGINE_API int	swmm_node_index (SWMM_Engine engine, const char *id)
	Look up a node's zero-based index by its string identifier.
SWMM_ENGINE_API const char *	swmm_node_id (SWMM_Engine engine, int idx)
	Get the string identifier of a node by index.
SWMM_ENGINE_API int	swmm_node_add (SWMM_Engine engine, const char *id, int type)
	Add a new node to the model.
SWMM_ENGINE_API int	swmm_node_set_invert_elev (SWMM_Engine engine, int idx, double elev)
	Set a node's invert elevation.
SWMM_ENGINE_API int	swmm_node_set_max_depth (SWMM_Engine engine, int idx, double depth)
	Set a node's maximum depth (distance from invert to crown).
SWMM_ENGINE_API int	swmm_node_set_surcharge_depth (SWMM_Engine engine, int idx, double depth)
	Set the allowed surcharge depth above the node's crown.
SWMM_ENGINE_API int	swmm_node_set_pond_area (SWMM_Engine engine, int idx, double area)
	Set the ponded surface area when depth exceeds the maximum.
SWMM_ENGINE_API int	swmm_node_set_initial_depth (SWMM_Engine engine, int idx, double depth)
	Set a node's initial water depth at simulation start.
SWMM_ENGINE_API int	swmm_node_get_type (SWMM_Engine engine, int idx, int *type)
	Get the type of a node.
SWMM_ENGINE_API int	swmm_node_get_invert_elev (SWMM_Engine engine, int idx, double *elev)
	Get a node's invert elevation.
SWMM_ENGINE_API int	swmm_node_get_max_depth (SWMM_Engine engine, int idx, double *depth)
	Get a node's maximum depth.
SWMM_ENGINE_API int	swmm_node_get_depth (SWMM_Engine engine, int idx, double *depth)
	Get the current water depth at a node.
SWMM_ENGINE_API int	swmm_node_set_depth (SWMM_Engine engine, int idx, double depth)
	Set the water depth at a node (runtime override).
SWMM_ENGINE_API int	swmm_node_get_head (SWMM_Engine engine, int idx, double *head)
	Get the current hydraulic head at a node (invert + depth).
SWMM_ENGINE_API int	swmm_node_get_volume (SWMM_Engine engine, int idx, double *volume)
	Get the current stored water volume at a node.
SWMM_ENGINE_API int	swmm_node_get_lateral_inflow (SWMM_Engine engine, int idx, double *inflow)
	Get the current lateral inflow at a node.
SWMM_ENGINE_API int	swmm_node_get_overflow (SWMM_Engine engine, int idx, double *overflow)
	Get the current overflow (flooding) rate at a node.
SWMM_ENGINE_API int	swmm_node_get_inflow (SWMM_Engine engine, int idx, double *inflow)
	Get the total inflow to a node (lateral + upstream links).
SWMM_ENGINE_API int	swmm_node_set_lateral_inflow (SWMM_Engine engine, int idx, double flow)
	Override the lateral inflow at a node for the current timestep.
SWMM_ENGINE_API int	swmm_node_set_head_boundary (SWMM_Engine engine, int idx, double head)
	Set a fixed head boundary condition at a node.
SWMM_ENGINE_API int	swmm_node_get_quality (SWMM_Engine engine, int node_idx, int pollutant_idx, double *conc)
	Get the pollutant concentration at a node.
SWMM_ENGINE_API int	swmm_node_set_storage_curve (SWMM_Engine engine, int idx, int curve_idx)
	Assign a storage curve (depth vs. area) to a storage node.
SWMM_ENGINE_API int	swmm_node_get_storage_curve (SWMM_Engine engine, int idx, int *curve_idx)
	Get the storage curve index assigned to a storage node.
SWMM_ENGINE_API int	swmm_node_set_storage_functional (SWMM_Engine engine, int idx, double a, double b, double c)
	Set functional storage parameters: Area = a * Depth^b + c.
SWMM_ENGINE_API int	swmm_node_get_storage_functional (SWMM_Engine engine, int idx, double *a, double *b, double *c)
	Get functional storage parameters.
SWMM_ENGINE_API int	swmm_node_set_storage_seep_rate (SWMM_Engine engine, int idx, double rate)
	Set the seepage rate for a storage node.
SWMM_ENGINE_API int	swmm_node_get_storage_seep_rate (SWMM_Engine engine, int idx, double *rate)
	Get the seepage rate for a storage node.
SWMM_ENGINE_API int	swmm_node_set_exfil_params (SWMM_Engine engine, int idx, double suction, double ksat, double imd)
	Set Green–Ampt exfiltration parameters for a storage node.
SWMM_ENGINE_API int	swmm_node_get_exfil_params (SWMM_Engine engine, int idx, double *suction, double *ksat, double *imd)
	Get Green–Ampt exfiltration parameters for a storage node.
SWMM_ENGINE_API int	swmm_node_set_outfall_type (SWMM_Engine engine, int idx, int type)
	Set the outfall boundary condition type.
SWMM_ENGINE_API int	swmm_node_get_outfall_type (SWMM_Engine engine, int idx, int *type)
	Get the outfall boundary condition type.
SWMM_ENGINE_API int	swmm_node_set_outfall_stage (SWMM_Engine engine, int idx, double stage)
	Set a fixed outfall stage (for FIXED type outfalls).
SWMM_ENGINE_API int	swmm_node_set_outfall_tidal (SWMM_Engine engine, int idx, int curve_idx)
	Assign a tidal curve to an outfall (for TIDAL type outfalls).
SWMM_ENGINE_API int	swmm_node_set_outfall_timeseries (SWMM_Engine engine, int idx, int ts_idx)
	Assign a time series to an outfall (for TIMESERIES type outfalls).
SWMM_ENGINE_API int	swmm_node_get_outfall_param (SWMM_Engine engine, int idx, double *param)
	Get the outfall stage parameter (fixed stage, or current computed stage).
SWMM_ENGINE_API int	swmm_node_set_outfall_flap_gate (SWMM_Engine engine, int idx, int has_gate)
	Set whether a flap gate exists at the outfall.
SWMM_ENGINE_API int	swmm_node_get_outfall_flap_gate (SWMM_Engine engine, int idx, int *has_gate)
	Get whether a flap gate exists at the outfall.
SWMM_ENGINE_API int	swmm_node_get_surcharge_depth (SWMM_Engine engine, int idx, double *depth)
	Get the surcharge depth above the node's crown.
SWMM_ENGINE_API int	swmm_node_get_ponded_area (SWMM_Engine engine, int idx, double *area)
	Get the ponded area at a node.
SWMM_ENGINE_API int	swmm_node_get_initial_depth (SWMM_Engine engine, int idx, double *depth)
	Get the initial depth at a node.
SWMM_ENGINE_API int	swmm_node_get_crown_elev (SWMM_Engine engine, int idx, double *elev)
	Get the crown elevation (invert + max depth) at a node.
SWMM_ENGINE_API int	swmm_node_get_full_volume (SWMM_Engine engine, int idx, double *vol)
	Get the full (maximum) stored volume at a node.
SWMM_ENGINE_API int	swmm_node_get_losses (SWMM_Engine engine, int idx, double *losses)
	Get the cumulative water losses at a node (evaporation + exfiltration).
SWMM_ENGINE_API int	swmm_node_get_outflow (SWMM_Engine engine, int idx, double *outflow)
	Get the total outflow from a node through downstream links.
SWMM_ENGINE_API int	swmm_node_get_degree (SWMM_Engine engine, int idx, int *degree)
	Get the degree (number of connected links) of a node.
SWMM_ENGINE_API int	swmm_node_get_stat_max_depth (SWMM_Engine engine, int idx, double *val)
	Get the maximum depth recorded at a node during the simulation.
SWMM_ENGINE_API int	swmm_node_get_stat_max_overflow (SWMM_Engine engine, int idx, double *val)
	Get the maximum overflow rate recorded at a node.
SWMM_ENGINE_API int	swmm_node_get_stat_vol_flooded (SWMM_Engine engine, int idx, double *val)
	Get the total flood volume at a node over the simulation.
SWMM_ENGINE_API int	swmm_node_get_stat_time_flooded (SWMM_Engine engine, int idx, double *val)
	Get the total time a node was flooded during the simulation.
SWMM_ENGINE_API int	swmm_node_get_depths_bulk (SWMM_Engine engine, double *buf, int count)
	Get depths for all nodes in a single call.
SWMM_ENGINE_API int	swmm_node_get_heads_bulk (SWMM_Engine engine, double *buf, int count)
	Get hydraulic heads for all nodes in a single call.
SWMM_ENGINE_API int	swmm_node_get_inflows_bulk (SWMM_Engine engine, double *buf, int count)
	Get total inflows for all nodes in a single call.
SWMM_ENGINE_API int	swmm_node_get_overflows_bulk (SWMM_Engine engine, double *buf, int count)
	Get overflow rates for all nodes in a single call.
SWMM_ENGINE_API int	swmm_node_set_depths_bulk (SWMM_Engine engine, const double *buf, int count)
	Set depths for all nodes in a single call (runtime override).
SWMM_ENGINE_API int	swmm_node_set_lat_inflows_bulk (SWMM_Engine engine, const double *buf, int count)
	Set lateral inflows for all nodes in a single call (runtime override).
SWMM_ENGINE_API int	swmm_node_get_quality_bulk (SWMM_Engine engine, int pollutant_idx, double *buf, int count)
	Get pollutant concentrations at all nodes for one pollutant.

Detailed Description

OpenSWMM Engine — Node C API.

Node add (BUILDING state), geometry setters, state get/set, lateral inflow injection (RUNNING), bulk access, quality.

See also

openswmm_engine.h

Author

Caleb Buahin caleb.nosp@m..bua.nosp@m.hin@g.nosp@m.mail.nosp@m..com

Copyright

Copyright (c) 2026 HydroCouple. All rights reserved.

License\n MIT License

Typedef Documentation

SWMM_NodeType

typedef enum SWMM_NodeType SWMM_NodeType

Node type classification.

Every node in a SWMM model belongs to one of these types. The type governs which property setters/getters are valid and how the node participates in routing.

Enumeration Type Documentation

SWMM_NodeType

enum SWMM_NodeType

Node type classification.

Every node in a SWMM model belongs to one of these types. The type governs which property setters/getters are valid and how the node participates in routing.

Enumerator
SWMM_NODE_JUNCTION	Standard junction node.
SWMM_NODE_OUTFALL	Outfall boundary node.
SWMM_NODE_STORAGE	Storage unit (pond, tank, etc.).
SWMM_NODE_DIVIDER	Flow divider.

Function Documentation

swmm_node_add()

SWMM_ENGINE_API int swmm_node_add	(	SWMM_Engine	engine,
		const char *	id,
		int	type
	)

Add a new node to the model.

The engine must be in SWMM_STATE_BUILDING. The node is appended to the model's node list and its index equals the previous count.

Parameters

engine	Engine handle.
id	Unique null-terminated identifier for the new node.
type	Node type (see SWMM_NodeType).

Returns

SWMM_OK on success, or an error code.

swmm_node_count()

SWMM_ENGINE_API int swmm_node_count

(

SWMM_Engine

engine

)

Get the total number of nodes in the model.

Parameters

engine

Engine handle.

Returns

Number of nodes, or -1 on error.

swmm_node_get_crown_elev()

SWMM_ENGINE_API int swmm_node_get_crown_elev	(	SWMM_Engine	engine,
		int	idx,
		double *	elev
	)

Get the crown elevation (invert + max depth) at a node.

Parameters

	engine	Engine handle.
	idx	Zero-based node index.
[out]	elev	Receives the crown elevation in project length units.

Returns

SWMM_OK on success, or an error code.

swmm_node_get_degree()

SWMM_ENGINE_API int swmm_node_get_degree	(	SWMM_Engine	engine,
		int	idx,
		int *	degree
	)

Get the degree (number of connected links) of a node.

Parameters

	engine	Engine handle.
	idx	Zero-based node index.
[out]	degree	Receives the number of links connected to this node.

Returns

SWMM_OK on success, or an error code.

swmm_node_get_depth()

SWMM_ENGINE_API int swmm_node_get_depth	(	SWMM_Engine	engine,
		int	idx,
		double *	depth
	)

Get the current water depth at a node.

Parameters

	engine	Engine handle.
	idx	Zero-based node index.
[out]	depth	Receives depth in project length units.

Returns

SWMM_OK on success, or an error code.

swmm_node_get_depths_bulk()

SWMM_ENGINE_API int swmm_node_get_depths_bulk	(	SWMM_Engine	engine,
		double *	buf,
		int	count
	)

Get depths for all nodes in a single call.

Parameters

	engine	Engine handle.
[out]	buf	Caller-allocated buffer of at least count doubles.
	count	Number of elements (should equal swmm_node_count()).

Returns

SWMM_OK on success, or an error code.

swmm_node_get_exfil_params()

SWMM_ENGINE_API int swmm_node_get_exfil_params	(	SWMM_Engine	engine,
		int	idx,
		double *	suction,
		double *	ksat,
		double *	imd
	)

Get Green–Ampt exfiltration parameters for a storage node.

Parameters

	engine	Engine handle.
	idx	Zero-based node index.
[out]	suction	Receives the suction head.
[out]	ksat	Receives the saturated hydraulic conductivity.
[out]	imd	Receives the initial moisture deficit.

Returns

SWMM_OK on success, or an error code.

swmm_node_get_full_volume()

SWMM_ENGINE_API int swmm_node_get_full_volume	(	SWMM_Engine	engine,
		int	idx,
		double *	vol
	)

Get the full (maximum) stored volume at a node.

Parameters

	engine	Engine handle.
	idx	Zero-based node index.
[out]	vol	Receives the full volume in project volume units.

Returns

SWMM_OK on success, or an error code.

swmm_node_get_head()

SWMM_ENGINE_API int swmm_node_get_head	(	SWMM_Engine	engine,
		int	idx,
		double *	head
	)

Get the current hydraulic head at a node (invert + depth).

Parameters

	engine	Engine handle.
	idx	Zero-based node index.
[out]	head	Receives the head in project length units.

Returns

SWMM_OK on success, or an error code.

swmm_node_get_heads_bulk()

SWMM_ENGINE_API int swmm_node_get_heads_bulk	(	SWMM_Engine	engine,
		double *	buf,
		int	count
	)

Get hydraulic heads for all nodes in a single call.

Parameters

	engine	Engine handle.
[out]	buf	Caller-allocated buffer of at least count doubles.
	count	Number of elements.

Returns

SWMM_OK on success, or an error code.

swmm_node_get_inflow()

SWMM_ENGINE_API int swmm_node_get_inflow	(	SWMM_Engine	engine,
		int	idx,
		double *	inflow
	)

Get the total inflow to a node (lateral + upstream links).

Parameters

	engine	Engine handle.
	idx	Zero-based node index.
[out]	inflow	Receives the total inflow in project flow units.

Returns

SWMM_OK on success, or an error code.

swmm_node_get_inflows_bulk()

SWMM_ENGINE_API int swmm_node_get_inflows_bulk	(	SWMM_Engine	engine,
		double *	buf,
		int	count
	)

Get total inflows for all nodes in a single call.

Parameters

	engine	Engine handle.
[out]	buf	Caller-allocated buffer of at least count doubles.
	count	Number of elements.

Returns

SWMM_OK on success, or an error code.

swmm_node_get_initial_depth()

SWMM_ENGINE_API int swmm_node_get_initial_depth	(	SWMM_Engine	engine,
		int	idx,
		double *	depth
	)

Get the initial depth at a node.

Parameters

	engine	Engine handle.
	idx	Zero-based node index.
[out]	depth	Receives the initial depth in project length units.

Returns

SWMM_OK on success, or an error code.

swmm_node_get_invert_elev()

SWMM_ENGINE_API int swmm_node_get_invert_elev	(	SWMM_Engine	engine,
		int	idx,
		double *	elev
	)

Get a node's invert elevation.

Parameters

	engine	Engine handle.
	idx	Zero-based node index.
[out]	elev	Receives the invert elevation in project length units.

Returns

SWMM_OK on success, or an error code.

swmm_node_get_lateral_inflow()

SWMM_ENGINE_API int swmm_node_get_lateral_inflow	(	SWMM_Engine	engine,
		int	idx,
		double *	inflow
	)

Get the current lateral inflow at a node.

Lateral inflow is the externally applied flow (DWF, RDII, user inflows) as opposed to the total inflow which includes upstream link contributions.

Parameters

	engine	Engine handle.
	idx	Zero-based node index.
[out]	inflow	Receives the lateral inflow in project flow units.

Returns

SWMM_OK on success, or an error code.

swmm_node_get_losses()

SWMM_ENGINE_API int swmm_node_get_losses	(	SWMM_Engine	engine,
		int	idx,
		double *	losses
	)

Get the cumulative water losses at a node (evaporation + exfiltration).

Parameters

	engine	Engine handle.
	idx	Zero-based node index.
[out]	losses	Receives the loss volume in project volume units.

Returns

SWMM_OK on success, or an error code.

swmm_node_get_max_depth()

SWMM_ENGINE_API int swmm_node_get_max_depth	(	SWMM_Engine	engine,
		int	idx,
		double *	depth
	)

Get a node's maximum depth.

Parameters

	engine	Engine handle.
	idx	Zero-based node index.
[out]	depth	Receives the maximum depth in project length units.

Returns

SWMM_OK on success, or an error code.

swmm_node_get_outfall_flap_gate()

SWMM_ENGINE_API int swmm_node_get_outfall_flap_gate	(	SWMM_Engine	engine,
		int	idx,
		int *	has_gate
	)

Get whether a flap gate exists at the outfall.

Parameters

	engine	Engine handle.
	idx	Zero-based node index.
[out]	has_gate	Receives 1 if flap gate present, 0 otherwise.

Returns

SWMM_OK on success, or an error code.

swmm_node_get_outfall_param()

SWMM_ENGINE_API int swmm_node_get_outfall_param	(	SWMM_Engine	engine,
		int	idx,
		double *	param
	)

Get the outfall stage parameter (fixed stage, or current computed stage).

Parameters

	engine	Engine handle.
	idx	Zero-based node index.
[out]	param	Receives the outfall parameter value.

Returns

SWMM_OK on success, or an error code.

swmm_node_get_outfall_type()

SWMM_ENGINE_API int swmm_node_get_outfall_type	(	SWMM_Engine	engine,
		int	idx,
		int *	type
	)

Get the outfall boundary condition type.

Parameters

	engine	Engine handle.
	idx	Zero-based node index.
[out]	type	Receives the outfall type code.

Returns

SWMM_OK on success, or an error code.

swmm_node_get_outflow()

SWMM_ENGINE_API int swmm_node_get_outflow	(	SWMM_Engine	engine,
		int	idx,
		double *	outflow
	)

Get the total outflow from a node through downstream links.

Parameters

	engine	Engine handle.
	idx	Zero-based node index.
[out]	outflow	Receives the outflow in project flow units.

Returns

SWMM_OK on success, or an error code.

swmm_node_get_overflow()

SWMM_ENGINE_API int swmm_node_get_overflow	(	SWMM_Engine	engine,
		int	idx,
		double *	overflow
	)

Get the current overflow (flooding) rate at a node.

Overflow occurs when the water depth exceeds the node's maximum depth and ponding is not enabled (or the ponded area is exceeded).

Parameters

	engine	Engine handle.
	idx	Zero-based node index.
[out]	overflow	Receives the overflow rate in project flow units.

Returns

SWMM_OK on success, or an error code.

swmm_node_get_overflows_bulk()

SWMM_ENGINE_API int swmm_node_get_overflows_bulk	(	SWMM_Engine	engine,
		double *	buf,
		int	count
	)

Get overflow rates for all nodes in a single call.

Parameters

	engine	Engine handle.
[out]	buf	Caller-allocated buffer of at least count doubles.
	count	Number of elements.

Returns

SWMM_OK on success, or an error code.

swmm_node_get_ponded_area()

SWMM_ENGINE_API int swmm_node_get_ponded_area	(	SWMM_Engine	engine,
		int	idx,
		double *	area
	)

Get the ponded area at a node.

Parameters

	engine	Engine handle.
	idx	Zero-based node index.
[out]	area	Receives the ponded area in project area units.

Returns

SWMM_OK on success, or an error code.

swmm_node_get_quality()

SWMM_ENGINE_API int swmm_node_get_quality	(	SWMM_Engine	engine,
		int	node_idx,
		int	pollutant_idx,
		double *	conc
	)

Get the pollutant concentration at a node.

Parameters

	engine	Engine handle.
	node_idx	Zero-based node index.
	pollutant_idx	Zero-based pollutant index.
[out]	conc	Receives the concentration in pollutant units.

Returns

SWMM_OK on success, or an error code.

swmm_node_get_quality_bulk()

SWMM_ENGINE_API int swmm_node_get_quality_bulk	(	SWMM_Engine	engine,
		int	pollutant_idx,
		double *	buf,
		int	count
	)

Get pollutant concentrations at all nodes for one pollutant.

Parameters

	engine	Engine handle.
	pollutant_idx	Zero-based pollutant index.
[out]	buf	Caller-allocated buffer of at least count doubles.
	count	Number of elements (should equal swmm_node_count()).

Returns

SWMM_OK on success, or an error code.

swmm_node_get_stat_max_depth()

SWMM_ENGINE_API int swmm_node_get_stat_max_depth	(	SWMM_Engine	engine,
		int	idx,
		double *	val
	)

Get the maximum depth recorded at a node during the simulation.

Parameters

	engine	Engine handle (ENDED or RUNNING state).
	idx	Zero-based node index.
[out]	val	Receives the maximum depth in project length units.

Returns

SWMM_OK on success, or an error code.

swmm_node_get_stat_max_overflow()

SWMM_ENGINE_API int swmm_node_get_stat_max_overflow	(	SWMM_Engine	engine,
		int	idx,
		double *	val
	)

Get the maximum overflow rate recorded at a node.

Parameters

	engine	Engine handle.
	idx	Zero-based node index.
[out]	val	Receives the maximum overflow in project flow units.

Returns

SWMM_OK on success, or an error code.

swmm_node_get_stat_time_flooded()

SWMM_ENGINE_API int swmm_node_get_stat_time_flooded	(	SWMM_Engine	engine,
		int	idx,
		double *	val
	)

Get the total time a node was flooded during the simulation.

Parameters

	engine	Engine handle.
	idx	Zero-based node index.
[out]	val	Receives the flooded duration in hours.

Returns

SWMM_OK on success, or an error code.

swmm_node_get_stat_vol_flooded()

SWMM_ENGINE_API int swmm_node_get_stat_vol_flooded	(	SWMM_Engine	engine,
		int	idx,
		double *	val
	)

Get the total flood volume at a node over the simulation.

Parameters

	engine	Engine handle.
	idx	Zero-based node index.
[out]	val	Receives the flooded volume in project volume units.

Returns

SWMM_OK on success, or an error code.

swmm_node_get_storage_curve()

SWMM_ENGINE_API int swmm_node_get_storage_curve	(	SWMM_Engine	engine,
		int	idx,
		int *	curve_idx
	)

Get the storage curve index assigned to a storage node.

Parameters

	engine	Engine handle.
	idx	Zero-based node index.
[out]	curve_idx	Receives the curve index, or -1 if functional.

Returns

SWMM_OK on success, or an error code.

swmm_node_get_storage_functional()

SWMM_ENGINE_API int swmm_node_get_storage_functional	(	SWMM_Engine	engine,
		int	idx,
		double *	a,
		double *	b,
		double *	c
	)

Get functional storage parameters.

Parameters

	engine	Engine handle.
	idx	Zero-based node index.
[out]	a	Receives coefficient a.
[out]	b	Receives exponent b.
[out]	c	Receives constant c.

Returns

SWMM_OK on success, or an error code.

swmm_node_get_storage_seep_rate()

SWMM_ENGINE_API int swmm_node_get_storage_seep_rate	(	SWMM_Engine	engine,
		int	idx,
		double *	rate
	)

Get the seepage rate for a storage node.

Parameters

	engine	Engine handle.
	idx	Zero-based node index.
[out]	rate	Receives the seepage rate.

Returns

SWMM_OK on success, or an error code.

swmm_node_get_surcharge_depth()

SWMM_ENGINE_API int swmm_node_get_surcharge_depth	(	SWMM_Engine	engine,
		int	idx,
		double *	depth
	)

Get the surcharge depth above the node's crown.

Parameters

	engine	Engine handle.
	idx	Zero-based node index.
[out]	depth	Receives the surcharge depth in project length units.

Returns

SWMM_OK on success, or an error code.

swmm_node_get_type()

SWMM_ENGINE_API int swmm_node_get_type	(	SWMM_Engine	engine,
		int	idx,
		int *	type
	)

Get the type of a node.

Parameters

	engine	Engine handle.
	idx	Zero-based node index.
[out]	type	Receives the node type (see SWMM_NodeType).

Returns

SWMM_OK on success, or an error code.

swmm_node_get_volume()

SWMM_ENGINE_API int swmm_node_get_volume	(	SWMM_Engine	engine,
		int	idx,
		double *	volume
	)

Get the current stored water volume at a node.

Parameters

	engine	Engine handle.
	idx	Zero-based node index.
[out]	volume	Receives the volume in project volume units.

Returns

SWMM_OK on success, or an error code.

swmm_node_id()

SWMM_ENGINE_API const char * swmm_node_id	(	SWMM_Engine	engine,
		int	idx
	)

Get the string identifier of a node by index.

Parameters

engine	Engine handle.
idx	Zero-based node index.

Returns

Null-terminated string owned by the engine, or NULL on error.

swmm_node_index()

SWMM_ENGINE_API int swmm_node_index	(	SWMM_Engine	engine,
		const char *	id
	)

Look up a node's zero-based index by its string identifier.

Parameters

engine	Engine handle.
id	Null-terminated node identifier.

Returns

Zero-based index, or -1 if not found.

swmm_node_set_depth()

SWMM_ENGINE_API int swmm_node_set_depth	(	SWMM_Engine	engine,
		int	idx,
		double	depth
	)

Set the water depth at a node (runtime override).

Parameters

engine	Engine handle (RUNNING state).
idx	Zero-based node index.
depth	New depth in project length units.

Returns

SWMM_OK on success, or an error code.

swmm_node_set_depths_bulk()

SWMM_ENGINE_API int swmm_node_set_depths_bulk	(	SWMM_Engine	engine,
		const double *	buf,
		int	count
	)

Set depths for all nodes in a single call (runtime override).

Parameters

engine	Engine handle (RUNNING state).
buf	Array of depth values, one per node.
count	Number of elements (should equal swmm_node_count()).

Returns

SWMM_OK on success, or an error code.

swmm_node_set_exfil_params()

SWMM_ENGINE_API int swmm_node_set_exfil_params	(	SWMM_Engine	engine,
		int	idx,
		double	suction,
		double	ksat,
		double	imd
	)

Set Green–Ampt exfiltration parameters for a storage node.

Exfiltration models soil infiltration losses from the bottom and banks of a storage unit using the Green–Ampt method.

Parameters

engine	Engine handle.
idx	Zero-based node index (must be SWMM_NODE_STORAGE).
suction	Soil capillary suction head (project length units).
ksat	Saturated hydraulic conductivity (project length/time).
imd	Initial moisture deficit (fraction: 0–1).

Returns

SWMM_OK on success, or an error code.

swmm_node_set_head_boundary()

SWMM_ENGINE_API int swmm_node_set_head_boundary	(	SWMM_Engine	engine,
		int	idx,
		double	head
	)

Set a fixed head boundary condition at a node.

Useful for outfall nodes or real-time coupled boundary conditions. Applied for the current timestep only.

Parameters

engine	Engine handle (RUNNING state).
idx	Zero-based node index.
head	Head boundary in project length units.

Returns

SWMM_OK on success, or an error code.

swmm_node_set_initial_depth()

SWMM_ENGINE_API int swmm_node_set_initial_depth	(	SWMM_Engine	engine,
		int	idx,
		double	depth
	)

Set a node's initial water depth at simulation start.

Parameters

engine	Engine handle.
idx	Zero-based node index.
depth	Initial depth in project length units.

Returns

SWMM_OK on success, or an error code.

swmm_node_set_invert_elev()

SWMM_ENGINE_API int swmm_node_set_invert_elev	(	SWMM_Engine	engine,
		int	idx,
		double	elev
	)

Set a node's invert elevation.

Parameters

engine	Engine handle.
idx	Zero-based node index.
elev	Invert elevation in project length units.

Returns

SWMM_OK on success, or an error code.

swmm_node_set_lat_inflows_bulk()

SWMM_ENGINE_API int swmm_node_set_lat_inflows_bulk	(	SWMM_Engine	engine,
		const double *	buf,
		int	count
	)

Set lateral inflows for all nodes in a single call (runtime override).

Parameters

engine	Engine handle (RUNNING state).
buf	Array of lateral inflow values, one per node.
count	Number of elements.

Returns

SWMM_OK on success, or an error code.

swmm_node_set_lateral_inflow()

SWMM_ENGINE_API int swmm_node_set_lateral_inflow	(	SWMM_Engine	engine,
		int	idx,
		double	flow
	)

Override the lateral inflow at a node for the current timestep.

Applied for one timestep only; call each step to sustain. This replaces any externally defined inflows (DWF, RDII, etc.) for this node during the current step.

Parameters

engine	Engine handle (RUNNING state).
idx	Zero-based node index.
flow	Lateral inflow in project flow units.

Returns

SWMM_OK on success, or an error code.

swmm_node_set_max_depth()

SWMM_ENGINE_API int swmm_node_set_max_depth	(	SWMM_Engine	engine,
		int	idx,
		double	depth
	)

Set a node's maximum depth (distance from invert to crown).

Parameters

engine	Engine handle.
idx	Zero-based node index.
depth	Maximum depth in project length units.

Returns

SWMM_OK on success, or an error code.

swmm_node_set_outfall_flap_gate()

SWMM_ENGINE_API int swmm_node_set_outfall_flap_gate	(	SWMM_Engine	engine,
		int	idx,
		int	has_gate
	)

Set whether a flap gate exists at the outfall.

A flap gate prevents reverse flow through the outfall.

Parameters

engine	Engine handle.
idx	Zero-based node index (must be SWMM_NODE_OUTFALL).
has_gate	Non-zero to enable flap gate; zero to disable.

Returns

SWMM_OK on success, or an error code.

swmm_node_set_outfall_stage()

SWMM_ENGINE_API int swmm_node_set_outfall_stage	(	SWMM_Engine	engine,
		int	idx,
		double	stage
	)

Set a fixed outfall stage (for FIXED type outfalls).

Parameters

engine	Engine handle.
idx	Zero-based node index (must be SWMM_NODE_OUTFALL).
stage	Fixed stage elevation in project length units.

Returns

SWMM_OK on success, or an error code.

swmm_node_set_outfall_tidal()

SWMM_ENGINE_API int swmm_node_set_outfall_tidal	(	SWMM_Engine	engine,
		int	idx,
		int	curve_idx
	)

Assign a tidal curve to an outfall (for TIDAL type outfalls).

Parameters

engine	Engine handle.
idx	Zero-based node index (must be SWMM_NODE_OUTFALL).
curve_idx	Zero-based curve index defining hour-of-day vs. stage.

Returns

SWMM_OK on success, or an error code.

swmm_node_set_outfall_timeseries()

SWMM_ENGINE_API int swmm_node_set_outfall_timeseries	(	SWMM_Engine	engine,
		int	idx,
		int	ts_idx
	)

Assign a time series to an outfall (for TIMESERIES type outfalls).

Parameters

engine	Engine handle.
idx	Zero-based node index (must be SWMM_NODE_OUTFALL).
ts_idx	Zero-based time series index defining time vs. stage.

Returns

SWMM_OK on success, or an error code.

swmm_node_set_outfall_type()

SWMM_ENGINE_API int swmm_node_set_outfall_type	(	SWMM_Engine	engine,
		int	idx,
		int	type
	)

Set the outfall boundary condition type.

Common types: 0=FREE, 1=NORMAL, 2=FIXED, 3=TIDAL, 4=TIMESERIES.

Parameters

engine	Engine handle.
idx	Zero-based node index (must be SWMM_NODE_OUTFALL).
type	Outfall type code.

Returns

SWMM_OK on success, or an error code.

swmm_node_set_pond_area()

SWMM_ENGINE_API int swmm_node_set_pond_area	(	SWMM_Engine	engine,
		int	idx,
		double	area
	)

Set the ponded surface area when depth exceeds the maximum.

When ponding is modeled, excess water is stored on the surface using this area. Set to 0 to disable ponding at this node.

Parameters

engine	Engine handle.
idx	Zero-based node index.
area	Ponded area in project area units (e.g., ft² or m²).

Returns

SWMM_OK on success, or an error code.

swmm_node_set_storage_curve()

SWMM_ENGINE_API int swmm_node_set_storage_curve	(	SWMM_Engine	engine,
		int	idx,
		int	curve_idx
	)

Assign a storage curve (depth vs. area) to a storage node.

Parameters

engine	Engine handle.
idx	Zero-based node index (must be SWMM_NODE_STORAGE).
curve_idx	Zero-based curve index (from swmm_curve_add()).

Returns

SWMM_OK on success, or an error code.

swmm_node_set_storage_functional()

SWMM_ENGINE_API int swmm_node_set_storage_functional	(	SWMM_Engine	engine,
		int	idx,
		double	a,
		double	b,
		double	c
	)

Set functional storage parameters: Area = a * Depth^b + c.

Defines the depth–area relationship using a power-law equation instead of a tabular curve.

Parameters

engine	Engine handle.
idx	Zero-based node index (must be SWMM_NODE_STORAGE).
a	Coefficient a.
b	Exponent b.
c	Constant c.

Returns

SWMM_OK on success, or an error code.

swmm_node_set_storage_seep_rate()

SWMM_ENGINE_API int swmm_node_set_storage_seep_rate	(	SWMM_Engine	engine,
		int	idx,
		double	rate
	)

Set the seepage rate for a storage node.

Parameters

engine	Engine handle.
idx	Zero-based node index (must be SWMM_NODE_STORAGE).
rate	Seepage rate in project length/time units.

Returns

SWMM_OK on success, or an error code.

swmm_node_set_surcharge_depth()

SWMM_ENGINE_API int swmm_node_set_surcharge_depth	(	SWMM_Engine	engine,
		int	idx,
		double	depth
	)

Set the allowed surcharge depth above the node's crown.

Parameters

engine	Engine handle.
idx	Zero-based node index.
depth	Surcharge depth in project length units.

Returns

SWMM_OK on success, or an error code.