# EPANET: Network Building Example

Network Building Example

This example shows how a network can be built just through toolkit function calls, eliminating the need to always use an EPANET formatted input file. This creates opportunities to use other sources of network data in one's code, such as relational database files or GIS/CAD files.

Below is a schematic of the network to be built.

#include "epanet2_2.h"
void netbuilder()
{
// Create a project that uses gpm for flow units and
// the Hazen-Williams formula for head loss
int index;
EN_Project ph;
EN_createproject(&ph);
EN_init(ph, "", "", EN_GPM, EN_HW);
// Add the first junction node to the project with
// an elevation of 700 ft and a demand of 0
EN_addnode(ph, "J1", EN_JUNCTION, &index);
EN_setjuncdata(ph, index, 700, 0, "");
// Add the remaining two junctions with elevations of
// 710 ft and demands of 250 and 500 gpm, respectively
EN_addnode(ph, "J2", EN_JUNCTION, &index);
EN_setjuncdata(ph, index, 710, 250, "");
EN_addnode(ph, "J3", EN_JUNCTION, &index);
EN_setjuncdata(ph, index, 710, 500, "");
// Add the reservoir at an elevation of 650 ft
EN_addnode(ph, "R1", EN_RESERVOIR, &index);
EN_setnodevalue(ph, index, EN_ELEVATION, 650);
// Add the tank node at elevation of 850 ft, initial water level
// at 120 ft, minimum level at 100 ft, maximum level at 150 ft
// and a diameter of 50.5 ft
EN_addnode(ph, "T1", EN_TANK, &index);
EN_settankdata(ph, index, 850, 120, 100, 150, 50.5, 0, "");
// Add the pipes to the project, setting their length,
// diameter, and roughness values
EN_addlink(ph, "P1", EN_PIPE, "J1", "J2", &index);
EN_setpipedata(ph, index, 10560, 12, 100, 0);
EN_addlink(ph, "P2", EN_PIPE, "J1", "T1", &index);
EN_setpipedata(ph, index, 5280, 14, 100, 0);
EN_addlink(ph, "P3", EN_PIPE, "J1", "J3", &index);
EN_setpipedata(ph, index, 5280, 14, 100, 0);
EN_addlink(ph, "P4", EN_PIPE, "J2", "J3", &index);
EN_setpipedata(ph, index, 5280, 14, 100, 0);
// Add a pump to the project
EN_addlink(ph, "PUMP", EN_PUMP, "R1", "J1", &index);
// Create a single point head curve (index = 1) and
// assign it to the pump
EN_addcurve(ph, "C1");
EN_setcurvevalue(ph, 1, 1, 1500, 250);
EN_setlinkvalue(ph, index, EN_PUMP_HCURVE, 1);
// Save the project for future use
EN_saveinpfile(ph, "example2.inp");
// Delete the project
EN_deleteproject(ph);
}