EPANET
Windows
v2.00.10
6/24/2002
Yes (PDF)
USEPA
EPANET is a computer program that performs extended period simulation of hydraulic and water quality behavior within pressurized pipe networks.

  A network can consist of pipes, nodes (pipe junctions), pumps, valves and storage tanks or reservoirs. EPANET tracks the flow of water in each pipe, the pressure at each node, the height of water in each tank, and the concentration of a substance throughout the network during a multi-time period simulation. In addition to substance concentrations, water age and source tracing can also be simulated.

EPANET is designed to be a research tool for improving our understanding of the movement and fate of drinking water constituents within distribution systems. The water quality module of EPANET is equipped to model such phenomena as reactions within the bulk flow, reactions at the pipe wall, and mass transport between the bulk flow and pipe wall. As we gain more experience and knowledge of water quality behavior within distribution systems we intend to update and refine EPANET to reflect this progress.

Another feature of EPANET is its coordinated approach to modeling network hydraulics and water quality. The program can compute a simultaneous solution for both conditions together. Alternatively it can compute only network hydraulics and save these results to a file, or use a previously saved hydraulics file to drive a water quality simulation.

The water quality module of EPANET can track the growth or decay of a substance by reaction as it travels through a distribution system. Reaction can occur both within the bulk flow and with material along the pipe wall. Bulk fluid reactions can also occur within tanks. EPANET models both types of reactions using first order kinetics. The bulk reaction is defined through a bulk reaction rate constant (Kb) while a wall reaction rate constant (Kw) is associated with the wall reaction. Different values for Kb can be used for different pipes and tanks in the network and the same holds true for Kw. Kb has units of 1/days while Kw has units of ft/day (or m/day). These coefficients are positive for growth reactions and negative for decay reactions.

EPANET views a water distribution network as a collection of links connected together at their endpoints called nodes. Links and nodes are identified with ID numbers and can be arranged in any fashion.

EPANET can be used for many different kinds of applications in distribution system analysis. Sampling program design, hydraulic model calibration, chlorine residual analysis, disinfectant loss and by-product formation study, and consumer exposure assessment are some examples. EPANET can help assess alternative management strategies for improving water quality throughout a system. These would include:

It can assist in evaluating alternative strategies for improving water quality such as altering source utilization within multi-source systems, modifing pumping and tank filling/emptying schedules to reduce water age, utilizing booster disinfection stations at key locations to maintain target residuals, and planning a cost-effective program of targeted pipe cleaning and replacement. EPANET can also be used to plan and improve a system's hydraulic performance. Pipe, pump and valve placement and sizing, energy minimization, fire flow analysis, vulnerability studies, and operator training are just some of the activities that EPANET can assist with.

The EPANET package contains two program modules. One is a network simulator that runs under DOS, receiving its input from a file and writing its output to another file. The user must use external programs to edit the input file and view or print the output file. (An optional DOS shell program is provided that interactively edits EPANET input, runs the simulator, and views or prints its output according to selections made from a menu). The second module is a Microsoft® Windows 3.x program that allows one to edit EPANET input data, run the simulator, and graphically display its results in a variety of ways on a map of the network. Thus there are two different ways to run EPANET -- under DOS or under Windows. It is believe that for most situations the visualization power of the Windows version is an essential aid in trying to comprehend the results of running EPANET and recommend that this mode be used if your computer hardware and software can support it.

This Windows version of EPANET provides an integrated environment for editing network input data, running hydraulic and water quality simulations, and viewing the results in a variety of formats. These include color-coded network maps, data tables, and time series graphs.

As a summary, EPANET can:

  • handle systems of any size
  • compute friction head loss using the Hazen-Williams, Darcy-Weisbach, or Chezy-Manning formulas
  • include minor head losses for bends, fittings, etc.
  • model constant or variable speed pumps
  • compute pumping energy and cost
  • model various types of valves including shutoff, check, pressure regulating, and flow control valves
  • allow storage tanks to have any shape (i.e., diameter can vary with height)
  • consider multiple demand categories at nodes, each with its own pattern of time variation
  • model pressure-dependent flow issuing from emitters (sprinkler heads)
  • base system operation on simple tank level or timer controls as well as on complex rule-based controls.

And EPANET's water quality analyzer can:

  • model the movement of a non-reactive tracer material through the network over time
  • model the movement and fate of a reactive material as it grows (e.g., a disinfection by-product) or decays (e.g., chlorine residual) with time
  • model the age of water throughout a network
  • track the percent of flow from a given node reaching all other nodes over time
  • model reactions both in the bulk flow and at the pipe wall
  • allow growth or decay reactions to proceed up to a limiting concentration
  • employ global reaction rate coefficients that can be modified on a pipe-by-pipe basis
  • allow for time-varying concentration or mass inputs at any location in the network
  • model storage tanks as being either complete mix, plug flow, or two-compartment reactors.

EPANET was developed by the Water Supply and Water Resources Division (formerly the Drinking Water Research Division) of the U.S. Environmental Protection Agency's National Risk Management Research Laboratory. It is public domain software that may be freely copied and distributed. 





EPANET Programmer's Toolkit




The 
EPANET Programmer's Toolkit is a dynamic link library 
(DLL) of functions that allow developers to customize EPANET's 
computational engine for their own specific needs. The 
functions can be incorporated into 32-bit Windows 
applications written in C/C++, Delphi Pascal, Visual 
Basic, or any other language that can call functions 
within a Windows DLL. There are over 50 functions that 
can be used to open a network description file, read 
and modify various network design and operating 
parameters, run multiple extended period simulations 
accessing results as they are generated or saving 
them to file, and write selected results to file in 
a user-specified format. 



The Tookit should prove useful for developing 
specialized applications, such as optimization 
or automated calibration models, that require 
running many network analyses as selected input 
parameters are iteratively modified. It also can 
simplify adding analysis capabilities to integrated 
network-modeling environments based on CAD, GIS, 
and database packages. 



A Windows Help file is available that explains 
how to use the various Toolkit functions and 
offers up some simple programming examples. The 
Toolkit also includes several different header 
files, function definition files, and .lib files that simplify 
the task of interfacing it with C/C++, Delphi, and Visual Basic code.  






Kentucky Pipes (KYPIPE) to EPANET Conversion - KYP2EPA




KYP2EPA is a program that takes a Kentucky Pipes (KYPIPE) input data set and
converts it into an EPANET input data set.  The KYPIPE data set is assumed to
adhere to the format specified in the KYPIPE User's Manual3.  KYP2EPA is run
from the DOS prompt with the following command:





	C:\EPANET> KYP2EPA  kypfile  epafile





where kypfile is the name of an existing KYPIPE file and epafile is the name of
the EPANET file to be produced.



KYP2EPA supports all of the KYPIPE modeling features except it ignores pipe
parameter changes and external inflows to tanks (Cards 4a-C, 4b-C and 5-C).
Each pipe in the KYPIPE file that contains a pump or valve is converted into two
links in the EPANET file; a new pump or valve link at the head end of the pipe
(including a new end node) followed by the original pipe.  The program also
assigns node numbers to all tanks and reservoirs in the KYPIPE file.  These
modifications are summarized by comment lines placed at the head of the
EPANET file.



An EPANET verification file will be generated if the geometric verification
option is included in the KYPIPE file.  The verification file has the same prefix as
the EPANET input file and a .VER extension.  Newly created nodes and nodes
connected to newly created links will not be included in the file.  This will cause
EPANET to issue a warning message when it is run unless these data are edited
into the .VER file by the user.





















        File
        Size
        Download


        EPANET v2.00.10 (6/24/2002)

		-- Installation program		
        1.4 MB 
        
                


        EPANET -- User Manual (PDF)
        1.0MB
        
                


        EPANET -- EPANET 2 Programmers Toolkit
        0.17MB
        
                


        EPANET -- EPANET 2 source code
        0.5MB
        
                


        EPANET -- List of EPANET 2 updates and bug fixes 
        2KB