Sustainable water allocation

This programme is focussed on understanding the effects of human use of surface and groundwater systems to inform more sustainable water allocation decisions that benefit ecosystems and communities.

Programme Leader: Dr Murray Hicks 


  • Investigate relationships between river flows, variability and environmental attributes and values to inform water allocation decisions.
  • Understand how different river flows maintain the in-stream physical environment and ecosystems.
  • Develop improved, more accurate and holistic methods for setting minimum flows for biota (e.g. sports fish).
  • Produce tools that assess effects on in-stream biota and reliability of water-supply of complex resource development across catchments and regions.  These address  the cumulative effects of multiple water uses, flow rules, water storage and climate change on waterways and take reliability, and alternative scenarios to assess large scale water management options.
  • Determine flow-dependent Maori cultural values in waterways and assist iwi participation in water management.
  • Develop methods to maintain physical habitat quality in managed rivers, including flushing of nuisance algae.

Research Projects

  • Modelling vegetation-impacted morphodynamics in braided rivers
  • Linking hydrology and ecology in macrophyte dominated streams in Canterbury
  • Cumulative Hydrological Effects Simulator (CHES)
  • More reliably defining the mid-range flows required to flush periphyton blooms
  • Flow requirements to sustain groundwater ecosystems.
  • Predicting groundwater discharge into spring-fed streams.
  • Linking cultural flow-requirements with science-based environmental flow assessment methods.
  • A tool for assessing the broad-scale effects of water allocation schemes on in-stream habitat and reliability of water supply.
  • Physically-based models for predicting ecological effects of river flow-regime change.
  • The influence of flow regime on fish communities in foothills-fed rivers and streams.

Research applications

Our Sustainable Water Allocation Programme (SWAP) has produced a series of tools and software to assist with determining and managing environmental flows.

Primary NIWA Team

Dr Doug Booker, Dr Phil Jellyman, Dr Cathy Kilroy, Dr Jo Hoyle, Dr Paul Franklin, Dr Jan Diettrich, Dr Amy Whitehead, Dr Eleanor Gee, Richard Measures, Arman Haddadchi.

Key science collaborators

  • Dr John Hayes, Cawthron Institute. Flow related habitat requirements for fish and developing in-stream habitat models with improved biological realism.
  • Dr Gail Tippa, Tipa & Associates. Developing mechanisms for proactive consideration of tangata whenua values in water allocation processes.
  • University of Canterbury. Significance of full flow regime to native fish in high-country braided streams.
  • Regional Councils, including: Environment Canterbury, Horizons Regional Council and Environment Southland.
  • Department of Conservation.
  • Deltares, Netherlands.
  • University of Wales, Aberyswyth.

Recent publications

See a list of our recent related publications

Our goal is for Irrimet to enhance irrigation and effluent-spraying decisions based on real-time conditions. [Credit: Ross Woods]