What Is Groundwater Monitoring? A Complete Guide

Groundwater monitoring is the systematic measurement of groundwater levels and groundwater quality over time, undertaken to manage groundwater resources, satisfy regulatory approvals and protect nearby assets and ecosystems. In Australia, groundwater accounts for 30% of national water consumption, supplying mines, towns, irrigators and groundwater-dependent ecosystems across every state and territory. When groundwater conditions change – whether through abstraction, contamination or climate – the consequences for project safety, environmental compliance and water supply can be significant.

This guide focuses on practical, engineering-led groundwater monitoring solutions: how monitoring systems are designed, what instrumentation is available, how data accuracy is maintained, and how automated data collection reduces risk for mining, civil infrastructure and environmental projects. Monitel is a Western Australian engineering firm that designs and operates automated groundwater monitoring systems across these sectors, producing defensible datasets that support long-term groundwater management and regulatory reporting. Automated monitoring supports compliance with Western Australian legislation and provides continuous visibility that manual programs cannot match.

What is groundwater and why does it need to be monitored?

Groundwater is water stored in the pores and fractures of soil, rock and sediment beneath the earth’s surface. It accumulates in geological formations known as aquifers, where groundwater flow moves slowly under the influence of hydraulic gradients – sometimes only metres per year. Unlike surface water, groundwater is largely invisible, making direct observation impossible without purpose-built monitoring infrastructure.

Australia depends heavily on groundwater sources. According to Geoscience Australia, groundwater comprises around 17% of accessible water resources but contributes roughly 30% of total water consumption nationally. In Perth, groundwater provides about 40% of the city’s total water supply, drawn primarily from the Gnangara and Jandakot groundwater mounds. Groundwater systems are vital for supporting ecosystems such as wetlands and native vegetation, and groundwater sustains local wetlands and urban ecosystems which rely on sufficient water levels beneath the water table.

Groundwater abstraction must be carefully managed to avoid long-term depletion and ecological damage. The Department of Water and Environmental Regulation oversees groundwater resources in Western Australia, and monitoring allows authorities to set groundwater allocation limits for sustainable extraction. Monitoring also helps regulators set and manage water licenses to prevent over-extraction. As rainfall patterns shift, monitoring has become critical in Perth due to declining rainfall and changing climate conditions, and groundwater monitoring plays a pivotal role in managing the effects of climate change on water resources across the continent. Without systematic water resource management and ongoing monitoring, there is no reliable basis for managing groundwater supply, protecting ecosystems or planning new infrastructure.

What is groundwater monitoring? (definition, scope and objectives)

Groundwater monitoring is the ongoing measurement and analysis of groundwater levels, pressures and groundwater quality parameters to understand aquifer behaviour, detect change and support engineering and environmental decisions. Monitoring focuses on tracking physical water levels and chemical quality over time – covering both quantity (hydraulic head, depth to water, flow direction, abstraction rates) and quality (pH, electrical conductivity, salinity, temperature, dissolved oxygen, turbidity, metals, nutrients, organic compounds, and biological indicators such as e coli).

Typical monitoring objectives include:

• Assessing impacts of mine dewatering on surrounding aquifers and neighbouring bores
• Verifying drawdown predictions against approved hydrogeological models
• Protecting groundwater-dependent ecosystems from adverse changes in water levels or quality
• Identifying potential contaminants and contamination pathways before they migrate offsite
• Supporting closure planning and long-term water management strategies

Monitoring detects pollutants before they impact human health and economic activity. Groundwater monitoring is crucial for assessing contamination risks, and groundwater quality sampling helps manage the risk of contamination and safeguard drinking water supplies – including drinking water sources. Historical industrial activities can lead to groundwater contamination, making monitoring essential even on sites with no current operations. Groundwater monitoring assesses water quality and contamination risks across a wide range of water quality parameters, and monitoring data supports understanding the interaction between groundwater and any adjacent surface water body.

The critical role of defensible, audit-ready datasets cannot be overstated. Groundwater monitoring ensures compliance with environmental approvals, and groundwater monitoring data must meet Australian and ISO standards.

Groundwater monitoring methods and instrumentation

Instrumentation choice depends on project requirements: bore construction, expected groundwater levels, groundwater quality conditions, the range of parameters to be measured, and the required monitoring frequency. The following methods represent the core of most monitoring programs.

Monitoring wells and observation bores. Groundwater monitoring involves drilling boreholes for sample collection and water sampling. Monitoring wells collect groundwater samples for analysis, while observation wells monitor groundwater conditions without sampling. Wells are typically made of stainless steel or PVC, with screened intervals placed at specific depths within the target aquifer. Proper sealing outside the screen (using bentonite or cement) prevents cross-contamination between geological layers. Borehole networks are vital for capturing background conditions and detecting environmental impacts across a site.

Piezometers. Piezometers measure pore water pressure in the ground and are widely used around embankments, tailings dams and tunnel excavations. Vibrating wire piezometers convert pressure into electrical signals, offering low drift, long service life and suitability for deep installations. Standpipe piezometers provide a simpler, lower-cost option for shallow applications where manual measurement is acceptable.

Submersible level transmitters. Slim-line hydrostatic probes designed for small-diameter boreholes measure depth to water and groundwater levels with high resolution. Typical specifications include diameters as small as 17 mm, accuracy of ±0.25% full scale, and pressure ranges suitable for bores from a few metres to over 250 m depth. Vented vs non-vented cable designs and cable materials are selected based on bore depth, salinity and required longevity.

Water quality sensors. Multi-parameter sondes allow continuous in-situ measurement of pH, temperature, electrical conductivity, dissolved oxygen, turbidity and total dissolved solids. Groundwater monitoring includes using multi-parameter probes to test health markers like pH and salinity. Field measurements can include flow, temperature, and oxygen concentration. These sensors are valuable for early warning of tailings seepage or contaminated groundwater plumes.

Manual methods. Electric water level tapes, bailers, grab sampler devices, submersible pumps and low-flow sampling equipment remain important. Low-flow groundwater sampling generates minimal purged water volume, helping to obtain a representative sample without excessive disturbance. Spot sampling and collecting samples manually is still appropriate for baseline programs, periodic compliance checks, and verification of automated sensor outputs. Each water sample must be collected using protocols that determine contamination risk and ensure defensibility. Advanced methods such as Electrical Resistivity Tomography are also used as a form of remote sensing to map subsurface water distribution, complementing direct borehole data. Even sediment and particles in bore water can influence sensor readings, so careful sample collection and bore development are essential.

The role of dataloggers, telemetry and automated groundwater monitoring solutions

Many Australian mines and infrastructure projects now prefer automated monitoring over purely manual programs. The drivers are straightforward: safety, cost, data frequency and increasingly strict regulatory expectations.

Dataloggers record groundwater levels and quality at fixed intervals – typically every 5 to 15 minutes – creating high-resolution time series that capture transient responses to rainfall, pump starts and dewatering operations. This process produces far richer datasets than periodic manual readings, enabling engineers and hydrogeologists to make informed decisions based on actual aquifer behaviour rather than snapshots. Automatic samplers can collect samples continuously or at set intervals, further reducing reliance on manual site visits.

Monitel designs telemetry systems using GSM/4G, satellite or UHF radio, selected based on the remoteness of borefields, available power (solar or mains), and how critical real-time data is to operations. Automated systems enable real-time tracking of groundwater levels using telemetry and sensors. Telemetric systems reduce site visits and improve data collection frequency and reliability, which is particularly valuable for remote tailings dams, deep borefields or confined spaces where sending personnel poses significant safety risks and high labour costs.

Data is pushed to cloud platforms or secure servers, where dashboards display current water levels, trends and alarm status. When thresholds are exceeded, automated alerts notify responsible engineers immediately. Continuous monitoring reduces the risk of regulatory breaches by eliminating data gaps that manual programs inevitably produce. Monitel typically designs end-to-end groundwater monitoring solutions – from borehole instrumentation through to telemetry and reporting – tailored to each project’s specific requirements rather than offering a one-size-fits-all package.

Data accuracy: corrections, calibration and defensible groundwater datasets

High-quality groundwater data is not optional. Poor-quality data can be more expensive than quality instrumentation once re-drilling, re-sampling and regulatory risk are factored in. Measurements taken over long periods are only valuable if they are accurate and consistently corrected.

The main factors affecting groundwater level accuracy for hydrostatic probes include:

• Temperature effects: Electronics and materials respond to temperature changes, causing zero-offset drift or sensitivity shifts. Sensors with built-in thermistors allow compensation, but without correction, fluid temperature variation can introduce systematic error.
• Barometric pressure: Non-vented sensors measure absolute pressure, which includes atmospheric fluctuations. Without barometric compensation – using vented cables or a separate barometric sensor – diurnal atmospheric pressure swings can produce false water level variations. For example, an uncorrected transducer in a shallow bore might show apparent water level changes of 5–10 mm that are entirely atmospheric, potentially triggering false alarms or misrepresenting drawdown.
• Density / salinity corrections: Hydrostatic pressure depends on fluid density. In saline aquifers, coastal bores or near tailings seepage, salinity variation changes the density of the water column. Without density correction, measured pressure head does not accurately represent true water level elevation.
• Sensor drift and cable stretch: Over time, sensors may drift from their calibrated baseline. Deep installations may also experience cable elongation under weight, affecting depth referencing.

Calibration and verification practices include factory calibration certificates, field checks against manual water level tape readings, and periodic validation of water quality sensors using reference standards. Monitel’s engineering team documents metadata rigorously – sensor type, serial numbers, bore construction details, datum references such as Top of Casing and metres above Australian Height Datum – so that groundwater levels and pore pressures can be audited, replicated in models and defended during regulatory review.

Regulatory drivers, risk reduction and practical applications in Australia

Groundwater monitoring is linked directly to approvals under the Environmental Protection Act, the EPBC Act and state water licensing regimes. Regulators increasingly expect continuous, defensible monitoring data rather than periodic manual snapshots. Groundwater monitoring is essential for environmental compliance in mining and across major infrastructure projects, and it helps determine suitable locations for new bores and guides urban development in water-sensitive areas.

The main risk drivers for Monitel’s clients include:

• Regulatory non-compliance and legal penalties: Gaps or delays in data collection can breach strict approval conditions, leading to fines, enforcement action or project shutdowns. Automated monitoring directly addresses this by producing continuous, audit-ready datasets.
• Geotechnical instability and construction delays: In complex projects – for example, tunnel excavations in coastal environments – unexpected changes in pore water pressure or groundwater levels can compromise structural safety. Real-time monitoring provides the immediate data needed to manage dewatering and prevent costly construction failures.
• Safety risks and labour costs: Sending personnel to remote or hazardous locations such as tailings dams or deep bore fields is expensive and poses significant safety risks. Automated platforms eliminate the need for frequent site visits by transmitting high-frequency data directly to the cloud.

Practical applications undertaken across Australian sites include monitoring drawdown around open pits and underground mines, tracking pore water pressures near tunnel drives, and monitoring seepage and groundwater levels around tailings dams and embankments. Early-warning triggers and alarm thresholds are set in automated systems to notify engineers when conditions approach critical limits – enabling timely, proactive water management rather than reactive reporting. Comprehensive monitoring networks with multiple bores at varying depths provide the spatial coverage needed to validate numerical models used in project approvals and ongoing operation.

Monitel’s engineering approach to groundwater monitoring systems

Monitel works as an engineering partner rather than a hardware reseller. The company’s involvement typically spans the full project lifecycle:

1. Design: Reviewing approval conditions, hydrogeological models and site constraints to design the monitoring network – bore locations, depths, screen intervals and instrument selection. This includes choosing between submersible level transmitters, vibrating wire piezometers and water quality sondes based on what the project actually requires.
2. Installation and commissioning: Coordinating with drilling contractors, ensuring correct sensor placement and datum referencing (TOC, mAHD), performing initial manual readings to verify sensor outputs, and establishing baseline data collection before operations begin.
3. Long-term performance: Remote system diagnostics, routine sensor checks, data validation workflows, and support for clients’ hydrogeologists during reporting cycles and audits.

In one mining project, Monitel deployed approximately sixty CT2X sensors across a 50 km plain for a salt and potash operation, continuously measuring conductivity, temperature, salinity, total dissolved solids and pressure. Real-time data from this network enabled the client to detect environmental changes early and demonstrate regulatory compliance across multiple reporting periods – replacing what would have been an impractical manual sampling program.

At the Alkimos Desalination Plant, Monitel installed vibrating wire piezometers at multiple locations to monitor moisture, settlement and pore water pressure during pre-loading and early construction phases. Real-time pore pressure data underpinned safe dewatering decisions and helped avoid schedule delays during a technically demanding coastal tunnel and infrastructure project.

Monitel’s value lies in producing accurate, actionable groundwater data that supports engineering and environmental decisions – not merely installing sensors.

Planning a groundwater monitoring program for your project

For engineers, hydrogeologists and environmental managers planning or upgrading a monitoring network, the following steps provide a practical framework:

• Define objectives clearly: Is the program designed for compliance, dewatering control, impact assessment, or contamination detection? Objectives drive every subsequent design decision.
• Review regulatory conditions: Understand what approvals require – monitoring frequency, parameters, trigger values, reporting format and data standards.
• Understand hydrogeological context: Review existing bore logs, aquifer properties and baseline data. Identify which aquifers are at risk and where groundwater-dependent ecosystems or neighbouring users may be affected.
• Select suitable instrumentation: Choose between standpipes, vibrating wire piezometers and submersible level transmitters based on bore diameter, depth, expected conditions and required accuracy. Decide whether continuous water quality monitoring is warranted at selected locations.
• Plan for operational practicalities: Consider access and safety at bore locations, power and telemetry coverage, data ownership and security, and integration with existing site data systems or cloud platforms.

Engaging specialist support early in the design process reduces the risk of installing instrumentation that does not meet project or regulatory requirements. Monitel is available to review proposed designs, advise on instrumentation selection, and develop automated groundwater monitoring solutions tailored to each site’s specific groundwater monitoring needs.

To discuss groundwater monitoring for an upcoming or existing project in mining, infrastructure or environmental management, contact Monitel to speak with our engineering team about designing a monitoring solution matched to your site conditions and regulatory requirements.