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Water Allocation Impacts on River Attributes (WAIORA)

WAIORA is a decision-support system designed to provide guidance on whether a water abstraction or discharge could have adverse impacts on the following environmental parameters:

  • dissolved oxygen
  • total ammonia
  • water temperature
  • habitat for aquatic life

WAIORA uses measurements of stream geometry and numerical models to estimate how these parameters change with flow, and compares the predicted changes to environmental guidelines, that can be specified by the user, to determine if an adverse effect is likely to occur, and what mitigation scenarios are likely to ameliorate any adverse impacts.

Results are presented graphically and in tables recording the predictions, input data, and guidelines. These can be printed, or cut and pasted into other applications, as required.

All evaluations can be saved in a Microsoft Access database, providing a record of parameters that were evaluated, details of the location, the proposed flow change, the model parameters that were used, and the predicted environmental changes.

Development of WAIORA version 2.0 was funded mainly by MfE and Auckland Regional Council, with contributions from Wellington Regional Council, Hawkes Bay Regional Council, Environment Waikato, Environment Southland and Nelson City Council.

WAIORA Decision Support System Software

We ask you to register before downloading the executable so that we can keep you informed of any software and research updates.

Register for and download AIORA.exe (v.2.0.29) (FOLDER, 1.8 MB)

WAIORA Technical Documents

User Guide (PDF 1.9 MB)
Procedure for Calculating Stream Total Ammonia Downstream of Inflows (PDF 479 KB)
Procedure for Calculating Stream Temperature (PDF 353 KB)
Total Ammonia Model – Validations (PDF 697 KB)
Water Temperature Model – Validations (PDF 1.4 MB)

Frequently Asked Questions

Some of the most frequently asked questions about WAIORA