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LatestWindows 64bitapprox. 325 MB2026-08-01
iRIC 4.2Download
Solver1DOther toolsRunoff, floods and inundation

Slope Area Computation (SAC)

Peak discharge from high-water marks (USGS slope-area method)

SAC can be used to compute peak flood discharges from measurements of high-water marks along a stream reach. The slope-area method used by the program is based on the U.S. Geological Survey (USGS) procedure presented in Techniques of Water Resources Investigations of the U.S. Geological Survey, book 3, chapter A2, "Measurement of Peak Discharge by the Slope-Area Method".

Developed by: USGS

What is the Slope-Area Computation (SAC)?

The Slope-Area Computation (SAC) is a solver used to compute peak flood discharges from measurements of high-water marks along a stream reach. The original approach was developed by T. Dalrymple and M. Benson of the U.S. Geological Survey (USGS) in the 1960s and subsequently modified and coded by a long list of USGS employees, including Janice Fulford. The solver was further improved and prepared for installation in iRIC by Keisuke Inoue of Mizuho Instrumentation and Research with direction from Jonathan Nelson, Bob Holmes and many other users at the USGS. The solver uses a general version of the slope-area method to estimate flows based on high-water marks and prescribed roughness values.

This page was imported from the current site and is awaiting review by the solver developer. Page on the current site

Releases and downloads

8

Distribution files are available after signing in with iRIC ID (manuals and examples are open to everyone).

Why sign in: so we can notify you of updates, and to show the project is used.

Installer

Apr 10, 2018SAC DocumentationJAMembers onlyGet
Apr 10, 2018SAC DocumentationENMembers onlyGet

Manual

Apr 10, 2018USER’S GUIDE TO SACJAMembers onlyGet
Apr 10, 2018USER’S GUIDE TO SACENMembers onlyGet

Examples and tutorials

Apr 10, 2018Data for SAC Tutorial 1JAMembers onlyGet
Apr 10, 2018Slope Area Computation - Tutorial 1JAMembers onlyGet
Apr 10, 2018Slope Area Computation - Tutorial 1ENMembers onlyGet
Apr 10, 2018Data for SAC Tutorial 1ENMembers onlyGet