P8 Urban Catchment Model
William W. Walker, Jr., Ph.D.

Jeffrey D. Walker, Ph.D.

Originally developed for
USEPA, Minnesota PCA,  & Wisconsin DNR

***** N E W   V E R S I O N *****

Download Draft Version 3.5   - Updated  3/21/2015
Version Notes  Installation Instructions  Documentation  P8 Web Site  User Forum

Version 3.5 supports Microsoft Excel 2013, Windows 10, and contains other minor repairs and enhancements.   See Version Notes and Installation Instructions.  This version has been prepared without agency or user support. 

Version 3.5 can be co-installed with the previous Version 3.4.

The P8 User Forum can be used to post questions and share experiences.  https://groups.google.com/forum/#!forum/p8-model

Please send an email if you download the program so that we can maintain a list of users.   Please report problems or suggestions and post them at the P8 User Forum.

We would like to begin collecting hourly precipitation and daily air temperature files from various regions to support other user applications and development of algorithms to generate hourly precipitation files based upon daily records.  The algorithms will facilitate applications, since hourly records are not readily available in many regions.  If you want to contribute, please post your datasets at the P8 User Forum.

The latest version supports input files from all previous versions.  If your input files are stored in the default program folder for a previous version, they can be copied into the program folder for the current version (C:\p8_UserFiles).  This can be done after installation.

Version 1 (1990) documentation provides detailed descriptions of algorithms and calibrations.  Updates are described in the web documentation for the current version.  The current version basically translates the DOS version with more bells/whistles and revised input/output formats.  Most of the underlying algorithms and calibrations (now 20-25 years old) have not been changed.   As far as I know, mass is still conserved and suspended particles still settle at about the same rate as they did in the 1980's, so the underlying concepts and calibrations are still valid. 

With the exception of street-sweeping efficiency factors, the default particle calibrations (NURP50, NURP90) based on information available as of 1990 have not been modified, users can create their own particle calibrations based on more recent and/or site-specific data.   If the default calibrations are used, the user (not P8) assumes that they are valid.

http://www.wwwalker.net/p8/v35/webhelp/splash.htm                                                 12/19/2015