What We Monitor
Monitoring Water Quality
The quality of water in our rivers and creeks is affected by a range of factors. The Healthy Waterways Waterwatch Program assesses:
- Water Temperature
- Dissolved Oxygen (DO)
- pH
- Electrical Conductivity
- Turbidity
- Phosphorus
- Nitrates/Ammonia
- Habitat
- Photopoints
- Water Bugs (Macroinvertebrates)
Water Temperature
Temperature affects the amount of oxygen that can be dissolved in water. Warmer water holds less oxygen. If there is extreme temperature change, many organisms will die. Water temperature can be affected by air temperature, exposure to sunlight and shade, turbidity of water and discharge of warmed water from industry.
Dissolved Oxygen (DO)
Dissolved Oxygen (DO), is the amount of oxygen found in the water. All creatures need oxygen to survive. Waterways gain oxygen from the atmosphere when water flows over riffles (rocks in water). Water can also become oxygenated by plants as a result of photosynthesis.
pH
The pH of water is a measure of hydrogen ion concentration. It shows the acidity or alkalinity of water. Measurement of pH is important for water quality as all aquatic animals and plants are adapted to specific pH ranges. The pH of water increases in warmer temperatures so pH levels can be affected by the time of day a sample is taken. The geology of the waterway can also affect the pH.
Electrical Conductivity (EC)
Electrical conductivity (EC) is generally used to measure the salinity of water. Salty water conducts electricity more readily than pure water. Salinity levels can be affected by geology and soils, rainfall, surface run-off, groundwater inflows, temperature, evaporation and dilution. Pollution in stormwater can also change the water’s electrical conductivity. Electrical conductivity is measured in microSiemens per centimetre (μS/cm).
Turbidity
Turbidity is the measure of how clear the water is and is measured in a unit called the Nephelometric Turbidity Unit (or NTU). The more particles, such as soil or algae, suspended in the water, the greater the turbidity. High turbidity reduces the amount of light passing through the water, which can affect the ability of plants to grow.
Phosphorus
Phosphorus is a nutrient that is normally found in water at low concentrations. It comes naturally from the weathering of rocks and the decomposition of organic material. Human activities can often result in high concentrations of phosphorus in waterways. Soil and fertiliser particles washed into the waterway can carry phosphorus. Sewage is also rich in this nutrient. High levels of phosphorus can result in problems such as algal blooms, excessive growth of aquatic weeds and loss of species diversity.
Nitrates/Ammonium
Nitrogen is a nutrient essential to all forms of life. The most common nitrogen compounds found in waterways come from decomposing organic material. High levels of Nitrogen in a waterway can result in poor waterway health and may be due to animal and human waste, nitrogen-containing fertilisers and industrial discharges. Healthy Waterways Waterwatch recommends that groups monitor Ammonium (NH4) when testing for Nitrogen, as it is safer than tests that assess other types of Nitrogen.
Habitat
Habitat is the environment required by a certain plant or animal to survive. Waterways provide a wide range of habitat, both in and out of the water. The amount and quality of the habitat is important for both the health of the waterway and the animals that live in and around it. Habitat includes vegetation, the shape of the waterway and stream bed and the presence of shelter in the water.
Photopoint Observations
Photopoint monitoring records changes over time. A photograph is taken at a particular location and then subsequent photos are taken over time from the same place. This is especially helpful in assessing habitat.
Water Bugs (Macroinvertebrates)
Water bugs (macroinvertebrates), are creatures such as snails, mites, bugs, beetles, dragonflies, freshwater crayfish and worms that live in rivers and streams. Some types of water bugs are sensitive to pollution and they can tell us how healthy our waterways are. Waterways with good quality water have many different kinds of water bugs.
