SAAS Version 4.1

SAAS Version 4.1 available.

SAMDC Version 1

SAMDC Version 1 available.


Download Aquatic Ecosystem Assessments for Rivers

SAAS Version 2

Streamflow Analysis and Assessment Software (SAAS)

This software is being developed as part of a research program focussing on hydrology-based environmental flow methods. The aim of the research is to increase our understanding of flow regimes, linkages to other physical processes, the combined influence on ecological function, and the result of altering these processes on the integrity of river systems. We are interested in methods to identify and quantify ecologically-important components of flow regimes, assess their alteration through time with respect to a reference condition, and relate hydrological alteration to changes in ecological condition. We are also interested in using this information to characterise and classify both natural and altered flow regimes. Thus the analyses and related methods in SAAS reflect a focus on environmental flow assessments. For example, the Log-Pearson Type III distribution has been used in several studies to relate bankfull discharges to flow magnitudes with recurrence intervals between 1.5 and 1.7 years. Since bankfull flow is an indicator often used in environmental flow assessments, the Log-Pearson Type III distribution was included in SAAS for consistency. The software is being made available to provide broader access to these analysis and assessment methods for those implementing instream or environmental flow methodologies and by doing so, hopefully support informed decisions on sustainable use of water resources. Outcomes of ongoing research will be implemented in future versions of SAAS as it becomes available.

Click on the links below to for screen shots that will give you a flavour of SAAS:

Analysis Settings
Hydrograph Explorer - Basic
Hydrograph Explorer - Indicators
Flow Analyses - Flow Duration Curves
Flow Analyses - Flood Frequency
Flow Analyses - Baseflow
Flow Analyses - Rate of Change
Flow Analyses - Highflow Events
Flow Assessment - Trends
Flow Assessment - Compare FDCs
Flow Assessment - Compare Flow Distributions (K-S test)
Flow Assessment - Compare Seasonality (Parde Coefficients)
Flow Assessment - Compare Variability (CV)
Export results

The software is being provided "as-is". Unfortunately we cannot offer in-depth technical support but the software has a well documented manual and is robust enough that you should not encounter any issues.

How to download and unzip the software package

SAAS is free. Making this tool available helps to achieve the goal of building greater understanding of flow regimes and faciltate informed resource management decisions on environmental flows. All that is asked is that you send an email requesting the password to unzip the software. We would also apprerciate brief information about your intended application and where you are in the world. Knowing the number of users and the applications will help guide decisions on further development and investment. Your privacy will be respected. For important bug fixes and updates, check back here regularly.

SAAS is programmed using Matlab and compiled as a 'standalone' package. However, it is necessary to have the Matlab Component Runtime (MCR) on your system which is available for download below and requires administrative priveledges to install.

SAAS has a bit of a delay when you start it up for the first time. Be patient, it is working in the background. Good things come to those who wait (especially when its free!).

Please DO NOT redistribute this software. If you know of someone else that may find this software useful please direct them to this website to obtain their own copy directly. Installation instructions are included in the reference manual.

System Recommendations

  • Windows XP or later
  • Minimum 600 MB hard drive space
  • 1.5 GHz Processor or faster
  • Minimum 1024 x 768 monitor resolution (If you have your monitor set for a higher resolution you might want to change it to this when running SAAS for a larger GUI.)
  • Minimum 1 GB RAM (or more for larger data sets)
  • Read/Write privileges to at least one folder on your computer
  • Administrative privileges during first time installation

Suggested Citation

Metcalfe, R.A. and Schmidt, B., 2016. Streamflow Analysis and Assessment Software (SAAS)(V4.1). [Online] Available: [Current year, Current day].


The following files were posted April 22, 2016

Click here to download SAASv4.1 program files, demo data, and reference manual (~ 5 MB).
Click here to download MCR Installer v 7.16 (~ 400 MB). If you previously downloaded and installed this version to use SAAS Version 4, you are already good to go.
Click here to request the unzip password, for general SAAS inquiries, and to report problems. Please specify "SAASv41 Password Request" in the subject line and let us know what you will be doing with it.

Version history

Major changes (ie. other than cosmetic) in successive SAAS versions are provided below.

Version 4.1 - posted for downloading April 22, 2016

  • Fixed a bug that would cause a crash when using certain winter season start dates and hourly data.
  • Fixed a bug in the High Flow Events panel that resulted in flow events at the start of a time series not being identified properly.

Flow Assessment
  • Renamed the "Compare FDCs" panel to "Flow Duration Curves" and added the Kolmogorov-Smirnov test (K-S test) to determine if there are statistical differences between an annual, seasonal or monthly flow distribution and a reference flow distribution.
  • Major changes were made to the "Compare Hydrographs" panel including.
    • The calculation of monthly Pardé-coefficients, monthly coefficient of variation, and monthly mean diel coefficient of variation (if using hourly data).
    • The user can plot the above statistics for any year or number of years for three separate periods as well as the associated hydrographs

Version 4.0 - posted for downloading February 27, 2015

  • The ability to choose from several date formats for the input file.
  • The ability to conduct analyses based on water years.
  • Up to 6 user-defined seasons now possible.
  • The ability to have a season extend over calendar years.
  • Can now input the basin area to allow the normalization of flows for streamflow comparisons in a new panel.
Hydrograph Explorer - Basic Panel.
  • Added the option of a log plot in the
Flow Duration Curves Panel
  • Added the ability to turn grid lines on and off in the
High Flow Events Panel
  • Changed the slider bars to user input boxes for the criteria values.
  • In Criterion 2 added the ability for the user to ignore rates of change of flow associated with peaks below a specific threshold to help isolate only those peaks of interest.
  • In Criterion 3 added the ability for the user to isolate only those peaks within a specific discharge range.
Rate of Change Panel
  • Added the ability to plot Absolute ROCs (m3 sec-1 hr-1) or Relative ROCs (% change per hr)
Flow Assessment Tab (new)
  • Trend Analysis Panel allows summaries of hydrologic indicators to be plotted annually and to test for trends using Mann-Kendall test statistics and the Sen's Slope Estimator
  • Compare FDCs Panel allows the comparison of individual years with the long term median flows and range of variability selected by the user as well as FDC comparisons between two datasets.
  • Compare Hydrographs Panel allows the user to compared stacked annual hydrographs from two time series on the same plot

Version 3.0 - posted for downloading November 2, 2012

  • Many 'cosmetic' changes to enhance useability.
  • Added the capability to load and analyse two time series concurrently. The two time series can be from the same file or two different files.
  • Zero flows now allowed.
  • Removed the option to enter metadata for the time series.
  • Added the ability for the user to define what percentiles to report around the median.
Hydrograph Explorer: Basic
  • Added the coefficient of variation, upper and lower quartiles, and relative dispersion to the summary statistics section.
  • Added the options to plot the upper and lower quartiles on the hydrograph plot.
Hydrograph Explorer: Indicators
  • In the High Flow Indicators section, replaced the mean duration statistic with percentile statistics.
  • Peak over threshold now includes all events greater-than or equal-to the thresold (used only greater-than in previous versions).
Flow Analyses: Baseflow
  • The issue of reporting erroneous 0s in the table now fixed
Flow Analyses: Highflow Events (New)
  • Added a new panel to analyse highflow events.
Flow Analyses: Rate of Change
  • Added ROC duration curves.
  • Added the ability to constrain ROC calculations to the rising and falling limbs of highflow events isolated using the new Highflow Events Panel.
  • Negative rates of change are now shown as negative values (show as absolute values in previous versions).
Flow Comparison (New)
  • Although currently only allowing a visual comparison of annual hydrographs for two time series, this panel will become more functional in future versions of SAAS.
  • Column labels added to exported tables.

Version 2.1.1 - posted for downloading on September 10, 2010

  • Reposted the same version to address a compiling issue that was causing problems in some installations.

Version 2.1.1 - posted for downloading on September 1, 2010

  • Fixed a bug that created an error message when viewing some FDCs.
  • All error messages now force the closure of SAAS to ensure the integrity of subsequent analyses are not comprimised.

Version 2.1 - posted for downloading on August 12, 2010

  • Added the option of generating an annual maximum series from daily data
  • Export and Report Tab: Exported filenames include a unique time stamp to avoid overwriting existing files
  • All FDC tables standardised to show 17 percentage points (0.01, 0.1, 1, 5, 10, 20, 30, 40, 50, 60, 70, 80, 90, 95, 99, 99.9 and 99.99 %)
  • Baseflow Tab: Graphic window changed to show boxplots
  • Baseflow Tab: First and last month of baseflow time series removed for analyses and display (i.e. to remove spin-up and wind-down effects)
  • Rate of Change Tab: Range of variability now shown using a boxplot and corresponding changes to table