What Type of Piezometer Should You Install in a Borehole?

The right piezometer will collect accurate and relevant data from a borehole, whilst a poorly suited sensor will leave you with holes in your findings. To make the most of your monitoring system, it is critical to select the right piezometer.

There various types available, each with their own features, installation methods and monitoring capabilities. When making a decision, you should consider these characteristics and the nature of your site.

This guide outlines the main types of piezometers we use and how to select the right one for your borehole monitoring needs. If you are unsure about what piezometer is suited to your site, please contact Monitel at admin@monitel.com.au or call (08) 6219 8284 for further assistance.

What Is a Piezometer?

A piezometer is an instrument used to measure the force of water held within the voids of soil or rock, known as pore water pressure. When installed in a borehole, a piezometer records water pressure at a specific depth, providing insight into groundwater behaviour, drainage and stability.

Piezometers can be used in a wide range of applications, including:

  • Monitoring the effectiveness of dewatering
  • Tracking groundwater changes in environmental assessments
  • Supporting slope stability and dam safety assessments
  • Meeting compliance obligations under WA regulations

At Monitel, we stock both manual and automated options, catering to different monitoring frequencies and data collection abilities.

Factors That Influence Your Choice

Several factors considerations should guide the selection of a piezometer for borehole use:

  • Monitoring Duration: Is this a short-term site investigation or a long-term compliance program?
  • Data Frequency: Will data be collected manually every few weeks or logged continuously in real time?
  • Installation Environment: Is the ground soft, firm, saturated or contaminated?
  • Depth and Accuracy Requirements: How deep is the borehole and how precise must the readings be?
  • Regulatory Requirements: Are there DWER, DMIRS or project-specific standards that must be met?

Having carefully considered these criteria and following discussion with an environmental consultant, you will be able to choose from one of the piezometers below.

Piezometers Commonly Installed in Boreholes

Vibrating Wire Piezometers (VWPs)

VWPs are ideal for long-term monitoring where accuracy and durability are essential. Installed at the target depth and connected to a data logger, they deliver stable readings over long cable runs and harsh site conditions.

Best for: Automated borehole systems, tailings dams, deep foundations

Examples of VWPs we stock include the W16 Kompakt and the W9.

Standpipe Piezometers

A simple and cost-effective option, standpipes consist of a slotted pipe installed in a borehole, typically at depths between 5 and 30 metres. When using these sensors, water levels are measured manually with a dip meter.

Best for: Short- to medium-term monitoring where manual readings are acceptable

Our most popular standpipe piezometer is the W1.

Pressure Transducer Piezometers

These sensors provide a continuous electrical signal, making them suitable for real-time monitoring and remote integration. They’re often used in boreholes that require consistent reporting, such as those in environmental compliance projects.

Best for: Continuous groundwater level tracking and integration with telemetry systems

The SGP-3400 Series is the most commonly used pressure transducer piezometer in our range.

Drive-In Piezometers

Designed for soft ground, these are installed without a pre-drilled borehole, using rods or CPT rigs. While less common in traditional borehole setups, they’re useful in tailings and unconsolidated material.

Best for: Soft sites where drilling is not feasible

The Monitel team often use the WP-3400 & SGP-3500 Series drive-in piezometers . Some of our other piezometers have a drive-in capacity available on request.

Strain Gauge Piezometers

Strain gauge piezometers use electrical strain gauges to detect pressure changes and respond quickly to dynamic site conditions.

Best for: Boreholes where fast response is required and integration with digital systems is planned

Monitel stocks the SGP-3400 strain gauge piezometer.

High-Temperature VW Piezometers

Where elevated ground temperatures may affect standard sensors, high-temperature VWPs provide reliable performance and long-term data. This could be in buried infrastructure or heated zones.

Best for: Boreholes in thermally active or industrial environments

The VWPHT-3600 is a high-temperature VWP we have deployed across Western Australia.

Hydraulic Piezometer

These sensors transmit fluid pressure to a pressure gauge via water-filled tubing. This setup allows measurements to be taken at the surface while the element remains isolated at depth.

Best for: Low permeability soils (like clays), sites that experience significant electromagnetic interference.

See our hydraulic piezometer.

Choosing the Right Setup

For some projects, a single piezometer at a specific depth is more than enough.

Elsewhere, it may be better to install multiple sensors within the same borehole to get a more accurate understanding of vertical pressure gradients.

Our team of environmental consultants tailors each system to the particular project or site, taking into account:

  • Borehole construction and casing
  • Site hydrology and stratigraphy
  • Project objectives and regulatory obligations

Enquire Today for Assistance with Borewell Piezometer Solutions

Selecting the right type of piezometer is key to collecting meaningful, actionable data from a borehole monitoring. Each sensor type offers distinct advantages and you may miss out on important insights should you make the wrong decision.

Monitel works closely with clients across WA to deliver tailored piezometer monitoring solutions that ensure accuracy, compliance and long-term value.

To discuss your borehole monitoring requirements or a possible monitoring solution, contact Monitel at admin@monitel.com.au or call (08) 6219 8284.

Why a Borehole Needs a Piezometer: Understanding Subsurface Water Behaviour

Boreholes act as a window into what’s happening beneath the surface. But in order too get the best insight, it is important to use the right instrumentation.

A piezometer is one of the tools best suited to extracting meaningful and actionable data form a borehole. They measure pore water pressure, helping engineers and asset managers understand how water is moving through soil and rock layers.

At Monitel, we have integrated piezometers into many borehole monitoring systems across Western Australia. Our solutions help you make safe, informed project decisions and are designed in line with regulatory requirements.

This article explains why piezometers are so useful in boreholes and how they explain subsurface water behaviour. If you are unsure about what is required on your site, you can speak with a member of our team at admin@monitel.com.au or call (08) 6219 8284.

What Is a Piezometer?

A piezometer is a device used for measuring ground water levels and pressures. These factors influence how stable or mobile the surrounding ground is, making piezometers a key instrument in geotechnical and environmental monitoring.

In borehole applications, piezometers are installed at specific depths to capture pressure conditions within that area. By installing one, stakeholders can monitor how groundwater behaves over time and whether it is causing instability, seepage or drainage issues.

What Is Subsurface Water Behaviour?

Subsurface water refers to groundwater and the pressure it exerts within soil or rock pores. Known as pore water pressure, this affects the stability, strength and drainage characteristics of the surrounding ground.

Variations in pore water pressure can be caused by rainfall, construction activity or dewatering and often lead to slope instability, foundation settlement or unexpected seepage.

Continual monitoring of subsurface water behaviour will help stakeholders:

  • Detect risks early
  • Develop informed design and construction plans
  • Comply with environmental and safety regulations

Why Should Piezometers be Installed in Boreholes?

Boreholes are commonly drilled for site investigations and long-term monitoring. Installing a piezometer in a borehole transforms it from a passive observation point into an ‘active monitoring system’.

An ‘active’ borehole will provide the following benefits:

Accurate Pressure Measurements at Depth

In boreholes, piezometers are installed at targeted depths to monitor specific geological layers. This allows users to track groundwater levels and pressure changes where they are most relevant to a structure. That might be below a foundation, within a dam wall or through a clay/sand interface.

Risk Detection for Stability and Safety

Works that cause ground movement can create a risk of pore pressure volatility. In applications like slope stability assessments and tailings dam monitoring, piezometer data can offer early warnings of changing pressures and prevent structural damage.

Environmental and Regulatory Compliance

Piezometers support compliance with WA legislation, including:

  • WHS (Mines) Regulations 2022
  • Mines Safety and Inspection Regulations 1995
  • DWER licensing conditions

Monitoring groundwater conditions in and around boreholes is often a requirement for environmental impact assessments, water management plans and mining proposals.

Long-Term Trend Analysis

Piezometers installed for extended periods can track seasonal groundwater fluctuations, effects of nearby construction and drainage performance. This information supports future development decisions.

Choosing the Right Piezometer for a Borehole

Different piezometers suit different borehole setups. Below we have listed some of the sensors in our piezometer range and their ideal applications:

  • Vibrating Wire Piezometers (VWPs): Ideal for long-term automated monitoring, with high accuracy and signal stability.
  • Standpipe Piezometers: Simple and cost-effective for manual level readings, typically installed at depths of 5–30 m.
  • Pressure Transducers: Provide continuous electrical output for integration with remote monitoring systems.
  • Multi-Point Piezometers: Allow for pressure profiling at multiple depths within the same borehole.

Our team will help you select and install the most suitable sensor based on project requirements, site conditions and budget constraints. For more information, you can read our article ‘Choosing the Right Piezometer Depth’.

Enquire Today for Borewell Piezometer Advice

Piezometers are perfect for extracting accurate and meaningful data from boreholes. They provide the information needed to assess groundwater behaviour, manage geotechnical risk and meet compliance obligations.

if you would like to speak to our team about borehole monitoring or a piezometer system, you can contact admin@monitel.com.au or call (08) 6219 8284

Choosing the Right Depth for Piezometer Placement in a Borehole

Piezometers are essential tools in borehole monitoring, providing measurements of groundwater pressure and supporting safe, informed decision-making across Western Australian industries.

However, without proper placement and depth selection, their effectiveness can be limited. At Monitel, we work closely with engineers, contractors and environmental professionals to determine appropriate sensor depths based on site conditions, monitoring goals and regulatory compliance.

This article outlines the key factors to consider when choosing sensor depth in a borehole installation. If you would prefer to speak with a member of our team, you can contact Monitel at admin@monitel.com.au or call (08) 6219 8284.

What are Piezometers?

Piezometers are instruments used to measure pore water pressure within soil or rock.

In boreholes, a piezometer can be used for monitoring water levels and pressure changes over time. This data is critical for understanding site stability and water movement.

If installed at a specific depth, a piezometer will provide data from a targeted layer of the ground. Information like this is used in applications such as dewatering, environmental compliance and slope stability analysis.

Borehole piezometers can be manual (like standpipes) or automated (like vibrating wire or pressure transducer models), depending on monitoring needs.

Why Depth Matters

Pore pressure varies with depth and can be influenced by geology, groundwater flow and changes in hydraulic gradients. Proper depth selection ensures the data is both relevant and reliable.

If a piezometer is installed too shallow, it may not capture critical subsurface conditions. If placed too deep, it may miss changes occurring in more active zones closer to surface activity or structural loads.

Key Considerations

Project Objective

The intended purpose of the piezometer should be the main factor in deciding its depth. For example:

  • Construction dewatering may require shallow installation to monitor drawdown levels.
  • Slope stability assessments often need mid-slope or multi-depth profiling.
  • Tailings dam monitoring typically targets foundation layers or phreatic surfaces.

Geological Layers

Understanding the layers soil and rock on your site is critical.

Installing a piezometer where two materials meet can reveal seepage or pressure changes associated with their different permeabilities. Borehole logs or site investigation data can guide this decision and help you identify where materials interface.

Groundwater Table Fluctuations

In areas where the water table varies due to seasonal change or human activity, select a depth below the expected fluctuation range to ensure consistent data.

In some cases, multiple piezometers can be installed at different depths in the same borehole to monitor vertical pressure.

Regulatory Requirements

Projects regulated by DWER, DMIRS or local council may mandate specific monitoring depths. This is particularly common in environmental licensing and compliance reporting projects.

Monitel references and applies these standards when designing our borehole systems, ensure their compliance.

Typical Depth Placement by Piezometer Type

Your chosen depth may influence the type of piezometer you use. Here are some of the sensors available in our piezometer range and the applications they are suited to:

  • Vibrating Wire Piezometers (VWPs): Often placed at specific stratigraphic targets in the borehole, such as within foundation layers, saturated zones or at the toe of a slope.
  • Standpipe Piezometers: These are typically installed at depths ranging from 5 to 30 metres, with the filter tip is surrounded by sand and sealed with bentonite to isolate the measurement zone.
  • Pressure Transducers: Can be installed at various depths depending on the required data range. It is suited to both shallow and deep installations.
  • Multi-point installations: Use multiple sensors within a single borehole to profile pressure at several depths, useful in complex or layered soils.
  • Hydraulic Piezometers: These are ideal for low-permeability soils and their fluid-filled design provides stable readings where electrical sensors may struggle.

Enquire About a Piezometer Solution for Your Borewell

Correct piezometer depth is essential for capturing useful, reliable and actionable pore pressure data.

Factors like site geology, monitoring objectives, groundwater dynamics and compliance requirements must all be considered during the planning process.

If you would like to discuss borehole monitoring on your site, please contact our team at admin@monitel.com.au or call (08) 6219 8284.