The U.S. Army Corps of Engineers (USACE), Hydrologic Engineering Center's (HEC) Statistical Software Package (HEC-SSP) is software that allows users to perform statistical analyses of hydrologic data.
The first official version of HEC-SSP (Version 1.0) was released in August of 2008. Version 1.1 was released in April, 2009 and included improvements to data entry, results visualization and reporting, and added capability to the Volume Frequency Analysis. Version 2.0 was released in October 2010 and included three new analyses: a Duration Analysis, a Coincident Frequency Analysis, and a Curve Combination Analysis. Version 2.1, released in July 2016, included improvements to the volume frequency analysis, general frequency analysis, and Bulletin 17 analysis as well as a new Balanced Hydrograph analysis. Version 2.2, released in June 2019, included improvements to nearly all previously-released analyses, two new analyses (Distribution Fitting and Mixed Population), a redesigned Curve Combination analysis, and enhanced data usage and manipulation.
Version 2.3, initially released in July 2022, includes improvements to nearly all previously-released analyses, two new analyses (Correlation and Record Extension), a redesigned Distribution Fitting analysis, and enhanced data import, visualization, and manipulation. These new features and options are discussed in the User's Manual for Version 2.3.
The HEC-SSP software is supported by Michael Bartles, Beth Faber, Matthew Fleming, and Greg Karlovits. The HEC-SSP user interface and computation code was programmed by Resource Management Associates and HEC. User documentation is updated by Michael Bartles, Matthew Fleming, Beth Faber, Greg Karlovits, Julia Slaughter, and Tricia North.