Monitoring
Wai Care Coordinators work with the community to gain information on the state of their local environment and assist in the planning and development of on the ground projects. They also provide training in assessment of catchment health, equipment use, sampling techniques and data interpretation.
Why Monitor
Changes in land-use activities, such as clearing of native vegetation, farming and increasing urban development have influenced the natural flow of water on and through our catchments. This in turn has affected the physical, chemical and biological features of our waterways.
By monitoring our waterways we are provided with an indication of catchment health. Monitoring over time can provide information on the state of the environment to assist with the maintenance and rehabilitation of our waterways.
Monitoring can:
- identify trends in water quality over time
- screen for potential water quality problems
- raise awareness of the local community or stream users to encourage pollution prevention and ownership of the local environment
- identify actions that can be taken and by whom, to help prevent water quality problems
- show government officials that the local community cares about the condition and management of its water resources
What is Monitoring?
Monitoring the quality of our water includes the following approaches:
Physical condition: determine land use patterns and presence of current and historical pollution sources; identify water uses, users, diversions and stream obstructions; sample flow rate, turbidity and temperature.
Biological condition: determine impacts of pollution sources, particularly land use activities, interpret biological data, screen for degraded sites (habitat survey); sample for aquatic invertebrates, presence of algae and faecal coliforms to assist in determining water quality.
Chemical condition: sample phosphorus, nitrates, pH (acidity & alkalinity) and dissolved oxygen.
Where to monitor
You can sample flowing waters in streams and rivers. If you live in an urban area you may only be able to sample in unnatural places for example in a concrete culvert or drain. If you live in the Waitakeres or Rodney District, chances are you’ll be able to sample in more natural waters.
Safety comes first:
Choose somewhere that is near to you and easy to access. If you’re sampling with younger children consider sampling in shallower, slow flowing areas. Make sure you obtain permission if you are sampling on privately owned land.
What do we monitor?
The range of tests outlined below are seen as as the most useful and practical tests for determining water quality and as indicators of pollution. Typical pollutants are excess nutrients (nitrates and phosphates), oxygen demanding substances and suspended sediment (reduced clarity). But you also want to know the amount of dissolved oxygen, the water temperature and the pH because these tell you whether the the right habitat is present to support stream life, i.e.fish, invertebrates, plants and algae etc.
Biological Parameters
|
Survey/Test |
What it Measures |
How Measured |
|
Habitat Assessment – riparian and instream |
An indication of the life support capacity of the stream and pressures from adjacent land use. |
Habitat assessment along a stretch of the stream. Each parameter is given a score. |
|
Biological Assessment
Macroinvertebrates
Bacterial indicators |
Abundance and diversity of aquatic macroinvertebrates.
Indicates the overall health of the waterbody
Numbers of bacterial indicator organisms indicates likely presence of pathogens in the waterway. |
Use nets to collect aquatic invertebrates and assess the results by calculating a score.
Standard bacterial test techniques using growth media. |
Physical Parameters
|
Survey/Test |
What it Measures |
How Measured |
|
Temperature
Turbidity/Visual Clarity
Water flow |
Temperature of the water
Murkiness of the water (relates to the amount of suspended particles in the waterbody and to water colour).
Volume and speed of water flow.
|
Thermometer
Clarity tube
Time a floating object along a measured streambed length then calculate flow rate. |
Chemical Characteristics
|
Survey/Test |
What it Measures |
How Measured |
|
Water pH
Dissolved oxygen (DO)
Nitrates
Phosphates
Biochemical oxygen demand (BOD) |
Acidity or alkalinity of the water
Amount of oxygen in the water, which is essential for the survival of most organisms.
Amount of nitrates in the water, which indicates organic enrichment.
Amount of phosphate in the water. Indicates the potential for eutrophic conditions to develop.
The amount of oxygen used by microorganisms to break down organic matter. |
pH test strips
AccuVac colorimetric DO test.
Nitrate test strips
Phosphate colorimetric method.
Measure the amount of DO and then again after 5 days. |
See Book 6 “Fact Sheets” to find out more information regarding:
- the importance of the water quality parameters you are measuring
- what activities cause them to change
- what effects these changes will have on stream life
- what solutions are available to avoid or remedy problems
- what range of values you would expect to find in Auckland Streams.
How to make the most of your monitoring
Work closely with your Wai Care Coordinator to develop a monitoring plan for your site. Mapping your catchment and its land uses will enable you to more accurately interpret your monitoring results as you will be more aware of the changes in land-use and be able to identify any that are human-induced.
Once your site has been selected, assess its surrounding health by conducting a habitat assessment. By examining the condition of the vegetation surrounding your monitoring site you will be better able to understand the health of the aquatic environment.
It is unlikely that you will be able to find sites that have all the ideal characteristics and the final choice should be primarily driven by safety considerations.
Useful sampling site features include:
- easy and safe access to mid stream water (if possible) or water at least 20cm deep.
- Open flat area nearby to lay out testing equipment and big enough for your group to work
- Shallow riffle or run areas for biological test
- Accessible all year round and easy to describe and locate
- A reasonable distance downstream from any drain – to allow mixing of water
- Above tidal influence
- Stable site that will not wash away during floods
- Shade trees present.
- At the simplest level Wai Care monitoring involves looking for obvious signs of stream water pollution and checking for unusual and unnatural smells.
Kaitiaki Monitoring
Tangata Whenua have specific measures by which to monitor the spiritual and physical health of waterways. Tikanga Maori and customary indicators based on intimate knowledge of their tribal environment will contribute to and in most cases correspond to the knowledge gained from scientific testing.
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