Groundwater investigations - North West region

Details of our active and completed groundwater investigations in the North West region of Western Australia
Map showing the locations of groundwater investigations in the North West region
North West groundwater investigations map

You can read about our investigations in the North West region below.

La Grange and Walyarta groundwater-dependent ecosystems

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La Grange, between Port Hedland and Broome, is a vital irrigation development area. Community water supply, pastoral stations, irrigation developments, mine water supply, tourism and mineral exploration all rely on groundwater. The area has important cultural and ecological values that also depend on groundwater.

Current groundwater management is underpinned by various cultural and water studies, from our hydrogeological investigations and information collected by licensees, to studies by the departments of Primary Industries and Regional Development and Biodiversity, Conservation and Attractions.

We need more information on how groundwater supports the environment to protect groundwater-dependent values and provide security for water users. The La Grange groundwater-dependent ecosystems investigation will analyse ecological, hydrogeological and nearshore components in the area.

This investigation began in 2019 and is due to finish in 2024. It is part of our State Groundwater Investigation Program.

Where to get more details

You can request more information about the La Grange groundwater-dependent ecosystems by emailing groundwater.info@dwer.wa.gov.au.

Hamersley Ranges groundwater assessment

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The expansion of iron ire mining at the start of the 21st century saw tremendous growth in the Pilbara region. Most mineral exploration and iron ore mining activities in the north-west Hamersley Range are associated with channel-iron deposits. These ancient, iron-rich alluvial sediments occupy meandering palaeochannels incised into basement rocks. They are also important regional aquifer systems containing valuable low-salinity groundwater.

The lack of low-salinity water resources on the Pilbara coast and the high cost of desalination was behind the need for an improved understanding of groundwater resources in the north-west Hamersley Range.

We undertook the desktop Hamersley Ranges assessment as part of the statewide Royalties for Regions Regional Water Availability program.

What we did during the investigation

Through the desktop Hamersley Range assessment we:

  • collated, reviewed, analysed and verified data from the former departments of Water and Mines and Petroleum, mining companies and other sources to identify potential groundwater sources
  • described each potential source in terms of its hydrology and hydrogeology
  • highlighted any considerations for groundwater development, including ecological and cultural values and potential impacts on existing groundwater users
  • ranked prospective areas to help prioritise investigations to refine the findings of this assessment.

Key findings and how we are using the information

We identified and quantified seven prospective areas with the potential to supply low-salinity, fit-for-purpose groundwater for West Pilbara towns, industry and irrigated horticulture. Water users and managers can use the updated knowledge this project has provided to support groundwater licence applications, and we will use it to manage groundwater resources.  

Where to get more details

The Prospectivity of new Hamersley Range groundwater resources fact sheet summarises our activities in the north-west Hamersley Range.

You can find the detailed hydrogeological assessment in Groundwater assessment of the north-west Hamersley Range, HG62.

Dampier Peninsula groundwater investigation

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This groundwater investigation aimed to improve our understanding of the Dampier Peninsula’s groundwater resources and how they support groundwater-dependent ecosystems north and east of Broome. We support community and economic development opportunities and regional growth by making water information publicly available. Water users and managers can use the information we gained from this project to support water licence applications, and we will use it to manage groundwater resources.

We conducted this groundwater investigation as part of the statewide Royalties for Regions Regional Water Availability program. It was made possible through strong working relationships with traditional owners and other groundwater users.

What we did during the investigation

During the study we:

  • collected 4,326 square kilometres of aerial electromagnetic data
  • constructed 35 bores
  • undertook ecological fieldwork at 35 sites
  • sampled water from surface waterbodies, rain, aquifers, soil and plant tissue.  

Key findings and how we are using the information

We now have a good understanding of the physical characteristics of the Broome Sandstone aquifer, including depth to groundwater, saturated thickness, recharge rates, location of the seawater interface and groundwater-dependent ecosystems. We have synthesised this information to identify areas where groundwater development might have fewer constraints and created a water opportunities ‘map’.

Key findings from the project include:

  • More information about the Broome Sandstone aquifer, which:
    • covers the whole study area and is fresh and generally unconfined
    • is typically within 20 metres of the surface near the coast and more than 80 metres below the surface over much of its inland extent
    • is around 100 metres thick in the centre of the peninsula, thickens to more than 500 metres in the north and thins where the confining layer is present
    • has estimated median recharge rates between 5 and 16 mm per year.
  • Identification of a new aquifer on the Dampier Peninsula underneath the Broome Sandstone aquifer and confining layer, which:
    • is fresh, has subartesian pressure where we drilled and is possibly artesian further south where the aquifer becomes shallower
    • spans over 930 square kilometres and is generally over 100 metres thick (according to aerial electromagnetic data).
  • The seawater interface is generally close to the coast but is up to 11 km inland around Willie Creek.

Where to get more details

Our Managing groundwater resources on the Dampier Peninsula fact sheet outlines new information about the physical characteristics of the Broome Sandstone aquifer, including depth to groundwater, saturated thickness, recharge, location of the seawater interface, the extent of the newly defined confined aquifer and the distribution of groundwater-dependent ecosystems, along with the water opportunities map.

The Groundwater-dependent ecosystems of the Dampier Peninsula report presents the findings of the ecological investigations, specifically the identification, characterisation and mapping of groundwater-dependent ecosystems.

You can request detailed information on the hydrogeological investigation by emailing groundwater.info@dwer.wa.gov.au.

Go to our Water Information Reporting portal to access data from the monitoring bores installed during the investigation.

Water for Pilbara Cities

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As part of the $25 million Royalties for Regions program, we completed extensive groundwater investigations from the Great Southern to the Kimberley, including the $12.5 million Water for Pilbara Cities investigation.

Before the Water for Pilbara Cities investigation, we were uncertain about groundwater recharge, perceived abstraction impact, aquifer characteristics, sustainable limits of abstraction and water quality in the West Canning Basin – Sandfire groundwater resource. These uncertainties resulted in risks to the sustainable management of the groundwater system and stifled investment from pastoralists and businesses.

By improving our understanding of fresh groundwater availability in the area, the Water for Pilbara Cities investigation has given greater certainty and confidence for regional development.

The investigation supported an increase in the groundwater allocation limit in the West Canning Basin – Sandfire resource from 30 GL/year to 50 GL/year. It also identified where further studies could help the long-term sustainable management of this resource.

What we did during the investigation

We conducted a program of drilling, airborne and downhole geophysics, water chemistry and isotope sampling, monitoring and aquifer testing to address some of the uncertainty and contribute to more robust groundwater management.

Through the study we:

Key findings and how we are using the information

Findings and outcomes from this investigation include:

  • Large volumes of groundwater can be discharged quickly from the Wallal aquifer over an extended period and the water is fresh (typically 250 to 600 mg/L).
  • We used the 3D numerical groundwater model to:
    • estimate the availability of groundwater under different climate scenarios
    • assess the cumulative impacts of abstraction on existing users
    • quantify the potential for drawdown to affect groundwater outflow at Mandora Marsh mound springs and other groundwater-dependent ecosystems
    • assess the potential of abstraction-induced seawater intrusion in the Canning–Wallal and Broome aquifers.
  • Information from this investigation informed our revised allocation limits and water resource objectives – see the West Canning Basin allocation statement 2018.
  • The monitoring network ensures we can evaluate the response of the groundwater resource to abstraction.
  • We will assess the resource against the objectives established during this project, which will tell us whether the allocation limits are sustainable.

Where to get more details

You can ask for copies of the internal technical reports prepared for this investigation by emailing groundwater.info@dwer.wa.gov.au. These include:

  • Bore completion report for the West Canning Basin – Sandfire groundwater investigation, HR374 (Department of Water 2017)
  • Inversion and preliminary interpretation of airborne electromagnetic data from the West Canning Basin – Sandfire TEMPEST survey (Mira Geoscience 2016)
  • West Canning Basin – Sandfire Project: hydrochemistry and isotope interpretation report, HR406 (DWER 2019)
  • West Canning Basin groundwater model report (PSM 2017)
  • West Canning Basin groundwater model – uncertainty analysis (PSM 2018)

Go to our Water Information Reporting portal to access data from the monitoring bores installed during the investigation.

Fitzroy groundwater investigation

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The Fitzroy River and surrounding catchment is an important part of the Kimberley with nationally recognised cultural, environmental and economic values. As interest in developing water resources to expand irrigated agriculture increases, we need to better understand how groundwater abstraction could impact the Fitzroy River and surrounding areas.

The Fitzroy groundwater investigation will help with water allocation planning and provide certainty for water users, Traditional Owners and the environment by providing new, targeted hydrogeological information.  All on-ground works are complete, and the final report is due in late 2021.

The Fitzroy groundwater investigation is a joint project under the State Groundwater Investigation Program (SGIP), Water for Food, and the Commonwealth funded Northern Australia Water Resource Assessment (NAWRA) program.

What we did during the investigation

So far, we have:

  • drilled 35 holes and installed 26 groundwater monitoring bores in the Grant-Poole aquifer, Fitzroy alluvium, Fairfield Group, Erskine Sandstone and Noonkanbah Formation
  • collected and analysed 75 samples from 61 groundwater bores to understand regional groundwater quality and identify where and how groundwater recharge occurs
  • collected 80 water samples along a ~ 300 kilometre stretch of the Fitzroy and Margaret Rivers, from Willare to Margaret Gorge, to assess how surface water and groundwater interacts
  • collected groundwater level data from 34 bores to determine how different wet seasons affect groundwater recharge, seasonal groundwater level fluctuation and the surface water groundwater interaction
  • completed an airborne electromagnetic survey over 20,000 square kilometres.

Key findings and how we are using the information

We now have a good understanding of:

  • where the potential groundwater resources of the Grant-Poole aquifer are
  • where the Noonkanbah Formation may prevent or reduce impacts to the Fitzroy River from groundwater abstraction in the Grant-Poole aquifer
  • the variable nature of the Fitzroy River alluvium
  • where increased groundwater use potentially impacts the Fitzroy River, Margaret River and significant tributaries, or other significant places
  • where and when groundwater recharge is highest, indicating most prospective areas
  • the times of year for groundwater use with the lowest level of environmental risk.

We will use this information to support groundwater licensing rules and allocation volumes while protecting environmental and social values.

Where to get more details

Data from monitoring bores installed as part of this investigation are accessible at the Department of Water and Environmental Regulation's Water Information Reporting portal.

All government commissioned airborne geophysical surveys are available via the Department of Mines, Industry Regulation and Safety website and can be downloaded free of charge from 'Geophysical Surveys' in  GeoVIEW.WA or from the Geophysical Archive Data Delivery System (GADDS).

Internal technical reports prepared as part of this investigation can be requested by emailing groundwater.info@dwer.wa.gov.au, including:

  • Bore Completion Report - Lower Fitzroy Drilling Program 2017, HR393 (Clohessy, 2017).
Page reviewed 8 June 2022