I have mentioned the EPANET toolkit several times before but didn’t post any information about it yet. The following info is from the toolkit readme file:
EPANET is a program that analyzes the hydraulic and water quality behavior of water distribution systems. The EPANET Programmer’s Toolkit is a dynamic link library (DLL) of functions that allows 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. The Toolkit DLL file is named EPANET2.DLL and is distributed with EPANET. The Toolkit comes with 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.
The freeware FireFlow utility was written using the EPANET toolkit.
For more information and download see EPANET web page.