“Hydrogeology is about geological environments that control the occurrence of groundwater” Freeze and Cherry (1979). We can estimate the quality and volume of groundwater that you may be able to obtain from your site, how the groundwater may affect your site development, and the best way to harvest that water.

Our team of expert hydrogeologists provide a range of technical and planning services for the management of groundwater resources. The team specialises in complex, multi-disciplinary projects with expertise in engineering hydrogeology, aquifer characterisation, contaminant hydrogeology, groundwater monitoring, numerical modelling and peer review services. The hydrogeology team comprises a group of innovative professionals providing a range of technical services to clients across New Zealand, Australia, and the wider Pacific region.

T+T and Lutra team up for safe drinking water

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Preliminary groundwater regime assessments

  • Desk study reviews and site history investigation

  • Preliminary risk assessments and walkover inspections

  • Feasibility assessments


  • 2D/3D groundwater flow and solute transport

  • Contaminant fate and solute transport modelling

  • Dewatering

  • Drawdown

  • Saline intrusion

  • Stream depletion

  • Seepage analysis

  • Dewatering assessments

  • Wellhead protection and capture zone analysis

Groundwater resource characterisation, assessment and protection

  • Municipal water supplies

  • Catchment Sanitary Inspections

  • Irrigation assessments

  • Well and spring source protection zones

  • GIS based risk assessment tool

Land development projects

  • Drawdown-related settlement effects analysis for infrastructure projects (e.g. basements, foundations, pipelines, tunnels, dams)

  • Dewatering assessments

  • Groundwater supplies for drinking, irrigation and industrial use

  • HVAC - using groundwater for heating/cooling systems

  • Municipal, Industrial and hazardous waste facilities

  • Containment facilities design

  • Determine private landfill trigger levels for regulatory compliance

Site characterisation, groundwater sampling and monitoring

  • Well design installation and development

  • Geological logging during bore drilling

  • Design, supervision and analysis of pumping tests, slug tests, packer tests

  • Resource consent compliance monitoring

  • Groundwater and surface water interaction characterisation

  • Development of hydrogeological conceptual models

  • Water balance and catchment analysis

  • Dye tracer testing

  • Data handling and analysis

Review services

  • Peer review of hydrogeological and modelling reports

Regulatory liaison

  • Strategic advice to local authorities

  • Community consultation

  • Technical support for resource consent applications

  • Preparation and presentation of expert evidence

Groundwater investigations and modelling

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Havelock North:

Technical investigations to determine the source of the Campylobacter outbreak which affected approximately 2000 Havelock North residents, and originated from the HDC Brookvale Rd bore field. Tonkin + Taylor’s input included extensive assessment of potential bacteriological sources within the catchment, contaminant fate and transport modelling and risk assessment, dye tracer tests, and numerical groundwater modelling. T+T completed detailed reporting in regard to those investigations, and prepared statements of evidence, and appeared for the Council at the Government Inquiry into the Havelock North Water Supply.

HVAC, Christchurch:

Heating, ventilation and air conditioning (HVAC) systems using groundwater as a source of energy for the heating or cooling of buildings have become increasingly common in new large scale commercial buildings in Christchurch CBD. Tonkin + Taylor have been involved with a number of projects involving the drilling of deep abstraction wells and shallow reinjection wells for HVAC systems and providing the site specific information on the groundwater regime to support resource consent applications for the operation of the HVAC systems. Our technical expertise supporting this project work includes provision of the drilling specification and design of the pumping test programme through to pumping test analysis, well interference assessments and groundwater modelling to determine the mounding effects and potential temperature plumes associated with groundwater reinjection.

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Greater Wellington Regional Council - Waiwhetu Aquifer Assessment

T+T were engaged by Greater Wellington Regional Council to provide specialist hydrogeological and project management services relating to investigation of bacteriological contamination of the Waiwhetu Aquifer and the possible relationship to the November 2016 Kaikoura earthquake. The investigation involved collating the results of independent investigations undertaken by ESR (Institute of Environmental Science and Research) and GNS (Geological and Nuclear Sciences Ltd) with our evaluation of the existing bore network and available groundwater quality data.

Whanganui District Council - Potable Water Supply

Part of a multi-disciplinary team within T+T to identify and assist with developing a new potable water supply source for Whanganui District Council. In addition to the Civil Engineering and Resource Management Planning aspects, the Hydrogeology Team provided technical assessments to develop a conceptual understanding of the hydrogeology in the vicinity of preferred sites and initially oversaw the drilling of a pilot bore so that the key aquifer characteristics could be used to estimate the sustainable yield of the aquifer. Sequential pilot drilling was undertaken to deepen the bore and improve the well yield. Drilling of the production bore resulted in a satisfactory sustainable yield for the potable water supply.

Key Contacts

Leon Pemberton, Discipline Manager - Auckland

Tony Cussins, Technical Director- Auckland

Hydrogeology Team

  • Leon Pemberton, Discipline Manager - Auckland

  • Tony Cussins, Technical Director - Auckland

  • Tony Reynolds, Senior Hydrogeologist - Auckland

  • Chris Shanks - Auckland

  • Sally Lochhead - Christchurch

  • Hannah Ross - Auckland

  • Kevin Ledwith - Auckland

  • Ryan Tutbury - Hamilton

  • Jeremy Bennett - Auckland

  • Tara Forstner - Auckland