What is the River Health Monitoring Program?
Since 1994, the Tasmanian Government has conducted broad-scale monitoring of river health across Tasmania under the River Health Monitoring Program (RHMP).
The results of the RHMP are used for a range of purposes relating to the management of natural resources (especially water) including:
- Water management and planning
- Catchment-scale river condition assessments
- Supporting environmental monitoring of industrial activities
- State of Environment reporting
The RHMP employs rapid sampling methods to assess river health, including Australian River Assessment System (AusRivAS) protocols, which focus on waterbug (macroinvertebrate) communities as well as measuring habitat indicators such as algal growth and fine deposited sediment levels on riverbeds.
The results of river health monitoring are published on the Data - Water Information Tasmania Web Portal under the parameter ‘River health Score OE’
River Health Monitoring Program Review
In 2018, a major review of the River Health Monitoring Program was undertaken to assess the program's value, its relevance and to guide the program into the future. The review resulted in improvements to existing methods and the addition of new indicators of river health to the monitoring program.
The results of the review are documented in a report:
Review of the Tasmanian River Health Monitoring Program (PDF 5Mb)
Why is river health monitored?
Rivers are a vital part of the Tasmanian landscape and sustaining their health (or condition) allows the benefits they provide to the community to be maintained. ‘River health’ is a broad concept that relates to the condition of river ecosystems, and includes water quality, the quality of habitats within rivers, and the composition of communities of aquatic plants and animals.
How do we assess river health in Tasmania?
The RHMP employs rapid bioassessment techniques to measure a number of components of river health as shown in the diagram (or Figure) below:
- Assessing the water bug community using the Australian River Assessment System (AusRivAS) forms a key component of the RHMP.
- AusRiVAS models predict the waterbug fauna that would be expected to occur at a site in the absence of environmental stress, such as pollution or habitat degradation. The predicted waterbug community is then compared to the measured waterbug community and the difference provides a powerful indicator of the health of the river.
- Alongside waterbug sampling, additional algae, fine deposited sediment, water quality and riparian condition are also assessed.
This diagram shows the different components of the river ecosystem that are measured to give an overall indication of river health.
More comprehensive assessments of river health can employ the Tasmanian River Condition Index (TRCI). However, it is recommended people wanting to employ the TRCI contact NRE Tas for guidance about its use.
A range of resources are available:
Book 1 Aquatic Life Field Manual (PDF 317Kb)
Book 2 Hydrology Suite of Programs (PDF 463Kb)
Book 3 Hydrology User Guide (PDF 806Kb)
Book 4 Streamside Zone Field Manual (PDF 1Mb)
Book 5 Data Analysis Tools (PDF 2Mb)
TRCI Refrence Manual (PDF 3Mb)
Note, the benthic algal monitoring method in the TRCI has been replaced with a new, more robust and informative method to monitor benthic algae (periphyton).
Periphyton monitoring method for rivers in Tasmania
(Version 1.0, September 2025)
This document outlines a new standard field method for assessing periphyton (riverbed algae) under Tasmania’s River Health Monitoring Program (RHMP). It replaces the benthic algal method under the Tasmanian River Condition Index (TRCI).
Developed by NRE Tasmania, and based on methods commonly used in New Zealand, the approach includes three sub-components:
Visual observations – a method for estimating percent cover of periphyton functional groups.
Biomass sampling – a method for determining periphyton biomass, based on chlorophyll-a.
Underwater photographs – instructions for capturing images to complement visual and biomass datasets.
Periphyton is one of three core indicators under the RHMP, alongside AUSRIVAS (macroinvertebrates) and fine deposited sediment. The method may be refined over time as statewide datasets are collected and analysed.
Download the document here:
Some standard equipment for river health monitoring. A water quality meter and an underwater viewer.
Waterbugs living on the riverbed are collected with a kick net. A member of the river health monitoring team is collecting a ‘kick-net’ sample from a riffle.
Waterbug samples collected from the riverbed are ‘live picked’ in the field prior to the samples being transported to the laboratory for identification.
Observing the condition of the riverbed using a underwater viewer is important for assessing river health.
Assessing the extent and health of riverbank vegetation improves understanding of river health.
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Measuring the amount of algae growing on the riverbed is an important indicator of nutrient enrichment and overall river health.
Waterbugs aren’t the only aquatic animals encountered during river health assessments in Tasmania (left: freshwater fish - Sandy, Pseudaphritis urvillii; right: frog - green and gold frog, Litoria raniformis).