STEDI is a water balance model that uses information such as streamflows, dam sizes, dam location, water use demands, rainfall and evaporation to simulate individual dams within a catchment. STEDI can be used to estimate:

  • how existing farm dams impact natural streamflows
  • how new farm dams would impact current streamflows.

The user can enter as much information about dam size, catchment areas and water use demands as is available. STEDI also allows the user to spatially configure a network of dams in a catchment so that inflows are influenced by upstream dams

STEDI can run at a daily, weekly, or monthly timestep, and given the proper inputs can model:

  • low flow bypasses around farm dams
  • farm dams that are manually 'topped-up' by pumping, for example from a local watercourse
  • changes in water use demands
  • the effects on flows from one dam to another through the catchment.

STEDI works by performing a water balance for each dam in a catchment, at each timestep. The user can choose the level of detail of output from the model.

STEDI output files can easily transfer to word processing and spreadsheet packages such as Microsoft Office to enhance presentation or to perform more detailed statistical analyses. They can also be used as an input to larger surface water modelling packages such as REALM or source catchments.

Find out more about source catchments on the eWater Cooperative Research Centre website.

STEDI is distributed as public domain software and can be downloaded free of charge.

Download STEDI

Would you like to learn how to use STEDI?

Sinclair Knight Merz and DELWP are considering holding a basic user training session if there is sufficient interest.

If you would like to participate, register your interest by emailing

STEDI has been developed and tested by Sinclair Knight Merz (SKM) in partnership with the DEPI. Program maintenance and limited user support is provided by SKM.

The public release of STEDI responds to widespread concerns about the possible impact of farm dams on water entitlements and environmental flows, and the growing need to accurately represent farm dam impacts in the face of climate change.

STEDI boasts additional features to its predecessor TEDI (Tool for Estimating Dam Impacts).

These additional tools allow STEDI to better model real catchment conditions and produce results that allow a better understanding of the behaviour of different types of farm dams.

The concepts underpinning both programs are discussed in two companion papers published in the July 2005 issue of the Australian journal of water resources.