River Science and Engineering

Rivers, streams and wetlands are highly sensitive and dynamic environments that provide vital life support functions to our ecosystems and at times pose significant hazards and risks to our built environment.

We have a team of specialist engineers, scientists and planners with expert skills and plenty of experience in the assessment and engineering of projects associated with rivers, streams and wetlands.


Our expertise includes:

  • Ecology

-  Environmental assessments of freshwater, marine and terrestrial areas including water and sediment quality.
-  Resource consent applications and processing.
-  Environmental monitoring for resource consent conditions compliance.

  • Hydrological and hydraulic assessment

-  Hydrological and hydraulic modelling of rivers for flood and debris flow hazard assessment, including effects of climate change and analysis of flood mitigation options.
-  Hydrological analysis for water availability for water supply, irrigation and hydro-electric generation.
-  River morphology and sediment transport assessments.

  • Geotechnical engineering

-  Risk-based stability assessments of existing stopbanks and river banks.
-  Site investigations and geotechnical assessment for design of river works.

  • River engineering

-  Flood mitigation works.
-  Debris flow mitigation works.
-  Sediment control works.
-  Erosion control works.
-  Wetland enhancement.
-  Weirs and water off-takes.
-  Diversion works and canals.
-  Culvert and bridge crossings.
-  Dams for water supply, water augmentation, flood detention and hydro-electric projects.


We have extensive experience working in and around rivers and wetlands in New Zealand, Asia, Africa and the Pacific.

Recent examples of our work include:

  • Tauranga Taupo River Flood Mitigation Scheme

This project involved assessment of the complex river morphology, hydraulic modelling and assessment of flood hazard, analysis of flood mitigation options including bank erosion works, stopbanks, overflow spillways, resource consent applications and consultation, detailed design and construction management of the works.

  • Tongariro River Flood Protection Scheme

This project involved a similar scope to the Tauranga Taupo project, with constructed works including erosion control measures, stopbanks, flood walls and gravel management in the river bed.

  • Ohau River Sedimentation Basin

We designed a sediment detention basin in the bed of the Ohau River to prevent sediment constricting the tailrace of the Ohau B hydropower station.

  • Piriaka Water Intake Enhancement

This project required assessment and design of remedial works to the intake on the Upper Wanganui River for the Piriaka hydropower scheme.

  • Mangakotukutuku Stream Diversion

Detailed design of new stream channel with enhanced environmental characteristics to facilitate open cast mining beneath the original stream bed.

  • Whangamarino Wetland Enhancement

We completed analysis of options and design of works to improve water level control to enhance ecological values.

  • Matata Debris Flow Remedial and Mitigation Scheme

We completed detailed morphological and hydrological assessment of the Matata Debris flow event of May 2005, and analysis of options for mitigation of future flood and debris flow events. Our detailed design of works included culvert upgrades, debris diversion bunds, erosion protection works and debris containment works (including a large debris flow barrier net for the Awatarariki Stream).

Key Contacts

Tom Bassett Tom Bassett

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