Bellingen Riverwatch data results supports the findings from the Bellinger and Kalang River Eco Health Report Card (2011) and the Bellinger River Health Plan (2010) and tells us that there are elevated nutrient levels in the river, particularly phosphate, and low Dissolved Oxygen levels. Phosphorus is a naturally occurring nutrient that originates from plant and animal matter, and is applied as fertilizer to increase plant growth in agriculture. Dissolved oxygen is a measure of the availability of oxygen to aquatic life. The amount of oxygen in the water regulates the distribution, activity, movement, and behavior of all aquatic animals.
From Bellingen Riverwatch data to date, we can see elevated Available Phosphate levels presenting in the Upper Bellinger River, Upper Kalang River, Upper Never Never River and Rosewood River. Low Dissolved Oxygen levels are presenting at sites in the Upper Bellinger River, on the Rosewood RIver and Spicketts Creek, and at all of our testing sites on the Kalang River and Never Never River. In the Bellinger and Kalang River Eco Health Report Card (2011), the Bellinger River received a B- mark, and the Kalang River received a C+ mark.
When interpreting data, we have used the ANZECC Water Quality Guidelines for a healthy lowlands river system. The graphs below show the Dissolved Oxygen and Available Phosphates data across the Bellinger and Kalang catchments July 2017 to March 2019.
How to read our graphs
Box and Whisker Plot
We have used a box and whisker plot to represent the complete data set from July 2017 to present. This plot style is commonly used to show key parameters regarding data sets. The maximum and minimum are represented via the whiskers and the box is showing average data and the median.
Average To Date Data NEW!
We now highlight on our graphs and maps (red dots) the sites where their to-date average (mean) does not meet the guidelines of a healthy river.
To improve legibility of our data, we have removed outliers. Outliers have been removed by determining the midpoint in the upper and lower quartiles, to define the upper and lower bounds of the data. Data outside these bounds has been removed to create the graphs below.
To aid interpretation of the water quality results, the parameters are scored against qualitative measures of the extent outside Guidelines. The definitions for assessment of results against the categories, and their indicated colours are as follows:
- Excellent = within ANZECC guideline
- Very Good = <25% outside ANZECC guideline
- Fair = outside the ANZECC guideline or 80th percentile trigger value by 25-50%
- Poor = Outside the ANZECC guideline or 80th percentile trigger value by 50-75%
- Very poor = >75% outside the ANZECC guideline or 80th percentile trigger value.
August 2019 Data
These results are from testing on the 13/14 August 2019 and 9/10 July 2019.
Phosphates are the essential plant and animal nutrient that occurs naturally in very low levels in Australian soils. The ANZECC Water Quality Trigger Values for Available Phosphates for moderately disturbed ecosystems for Lowland Rivers is 0.02mg/L.
TO DATE : 14/21 MEETS GUIDELINES 67% (7 sites at or above trigger value)
THIS MONTH : 7/12 MEETS GUIDELINES 58% (5 sites at or above trigger value)
LAST MONTH : 3/8 MEETS GUIDELINES 33% (5 sites at or above trigger value)
The graph below shows the Available Phosphate data across the Bellinger River, Kalang River, Never Never River, Rosewood River and Spicketts Creek from July 2017 to present.
What is the Data Telling Us?
The data tells us that the sites failing to meet ANZECC Guidelines for Available Phosphate (mg/L) for Healthy Rivers this month are B7, K1.1, NN1.2 and NN2.
The sites most regularly failing to meet the ANZECC Guidelines for Available Phosphate (mg/L) for Healthy Rivers (based on the average to-date data) are B2.1, then B2, then B4, K1.2, NN1.2, and R1 (see map below).
What happens outside the healthy range (shown in blue)?
Frequent occurrence of Available Phosphate results above 0.02mg/L could be harmful to aquatic ecosystems and increases the likelihood of impacts on waterways such as an abundance of algae and aquatic weeds which out-compete native plants; waterways choked with vegetation; increased biochemical oxygen demand; reduced dissolved oxygen; reduced plant and animal diversity; blue-green algal blooms; and eutrophication.
Possible causes of results outside these values include sewage, sediments erosion, faeces from feedlots, dairies and pets, phosphate-based detergents, decaying plant material, fertilisers and industrial waste and natural geological sources.
Scientists from the NSW Department of Planning, Industry & Environment (DPIE) are carrying out a comprehensive bi-annual water quality and macro-invertebrate surveys which will help identify the causes of elevated phosphate and nitrate levels.
The ANZECC Water Quality Values for Dissolved Oxygen for moderately disturbed ecosystems for Lowland Rivers (less than 150m elevation) is between 85% and 110% saturation.
TO DATE : 5/21 MEETS GUIDELINES 24% (16 sites outside green band for Healthy Rivers)
THIS MONTH : 4/14 MEETS GUIDELINES 29% (10 sites outside green band for Healthy Rivers)
LAST MONTH : 6/8 MEETS GUIDELINES 75% (2 sites outside green band for Healthy Rivers)
The graph below shows the Dissolved Oxygen data across the Bellinger River, Kalang River, Never Never River, Rosewood River and Spicketts Creek from July 2017 to present.
What is the Data Telling Us?
The data tells us that the sites failing to meet ANZECC Guidelines for Dissolved Oxygen (%sat) for a healthy river this month are K1, K1.1, K1.2, K4, NN1, NN.1, NN1.2, NN1.3, NN2, R1 and S1.
The sites most regularly failing to meet the ANZECC Guidelines for Dissolved Oxygen (%sat) for Healthy Rivers (based on the average to-date data) are B1, B2, B2.1, B5, K1, K1.1, K1.2, K2, K3, K4, NN1, NN1.1, NN1.2, NN1.3 and NN2 and S1 (see map below).
What happens outside the healthy range (shown in green)?
Results outside the guidelines could be harmful to ecosystems. Anything below 85% is a threat to aquatic life and the macro-invertebrates that our turtles love to eat. Potential impacts outside ANZECC trigger values include lack of oxygen to support aquatic plant and animal life and fish kills.
Monitoring Dissolved Oxygen levels is very important as the Bellingen River Snapping Turtle (BRST) is able to supplement its oxygen uptake through cloacal (bum) breathing, reducing its need to come to the water surface to breathe.
Possible causes of reduced oxygen levels in the river include low flow, stagnant water, organic waste such as sewage, fertiliser run-off and excessive algal growth in the waterway. Micro-organisms use the oxygen as they break down the organic matter.
Our October 2019 raw data spreadsheet is available here.