This product summarises water quality information in the Richmond river basin. Surface water quality may be directly impacted by runoff from areas altered by coal mines or coal seam gas (CSG) developments (areas cleared of vegetation, service roads, and site processing facilities), discharge of mine or CSG waters and leaking of hydrocarbons. A number of physical and chemical parameters may be altered by potential coal and CSG developments, including turbidity, suspended solids, pH, heavy metals concentration, salinity, and the presence of hydrocarbons. It is worth noting that there is currently a lack of data on the presence of hydrocarbons as a result of coal mining and CSG operation and development in the Clarence-Moreton bioregion.
The National Land and Water Resources Audit provides the only consistent bioregion-wide assessment of water quality . The National Land and Water Resources Audit provided data on the export of sediment, nutrient and phosphorus for the Richmond river basin and these were summarised in Section 1.1.5 of companion product 1.1 for the Clarence‑Moreton bioregion . A follow up report for the National Land and Water Resources Audit presented broader regional assessments and developed indices to facilitate comparison of basin and river condition. Section 1.1.5 also summarised some targeted monitoring campaigns reported in the scientific literature for the Richmond river basin. The Richmond River County Council monitors electrical conductivity, pH, dissolved oxygen, temperature and turbidity at four locations within the estuary.
The NSW Office of Water conducts two types of monitoring: continuous monitoring in river gauging stations and targeted monitoring campaigns for a specific duration and purpose . The remainder of this section will include a description of these two types of water quality monitoring products.
Of the active streamflow gauging sites in the Richmond river basin there are only two with continuous salinity and water temperature measurement datasets that are over one year in duration. These two gauges are Bungawalbyn (203450) and Richmond at Oakland Road (203470) and both are stations that only report river level as they are within the tidal zone of the basin. Monitoring of water quality parameters (salinity and temperature) at these two locations only commenced in early 2013. Data on the same parameters is also available for the Richmond River at Coraki (203403) but only since early 2014.
The data for Bungawalbyn (203450) and Richmond at Oakland Road (203470) can be seen in Figure 9 and Figure 10 for the 2013 to 2014 water year. For both sites, the monitoring locations exhibit seasonal water temperature characteristics which are likely to reflect variations in incoming solar radiation. On the other hand the salinity (expressed as electrical conductivity) in both systems seems to exhibit an increasing trend through the dry season, possibly in relation to decreases in baseflow and larger tidal influence, and then an abrupt decrease following a large flow event in March 2014. The salinity at Bungawalbyn ranges from 200 µS/cm after a large flow has been through the system (indicated by a big change in level) to nearly 1300 µS/cm before the next flushing event. A similar trend is shown at the Richmond River at Oakland Road although at this site maximum salinity is less than 800 µS/cm. These systems experience quite large ranges of salinity which may reflect variations in baseflow and tidal influences.
Figure 10 Stream level (top), electrical conductivity (middle) and water temperature (bottom) at gauge 203470 Richmond at Oakland Road for the 2013 to 2014 water year for the Clarence-Moreton bioregion
A range of other water sampling campaigns have also been undertaken to collect data for various reports and projects; some of these are summarised below. There are two main datasets to draw upon here: 1) the NSW Department of Environment and Heritage Historic Water Quality Data (Dataset 1), and 2) NSW Office of Water Data ().
State of the catchments – Northern Rivers Region (Dataset 1)
In 2010, the NSW Government undertook a State of the catchments report for the Northern Rivers region, which includes the Richmond river basin . In this report trends in water temperature, electrical conductivity and turbidity were presented for Richmond River at Kyogle, Wilson River at Eltham and Richmond River at Casino. This report acknowledges that there is low confidence in electrical conductivity and temperature data due to data gaps and errors and medium confidence in turbidity which was not measured past 2000.
Water Quality of Tweed, Brunswick, Richmond and Clarence rivers (Dataset 1)
This is an extensive dataset of more than 500 samples collected from 48 locations between 15 May 1994 and 12 April 1995. Water quality parameters available include turbidity, total phosphorus, total nitrogen, pH and temperature.
Other data (Dataset 1)
There are also two very small datasets which form part of the Coastal State Recreation Areas dataset (samples in 2006 and 2008) and the Monitoring River Health Initiative (samples collected between 1994 and 1999) . These both include measurements of electrical conductivity, turbidity, pH and temperature. The Coastal State Recreation Areas dataset has measurements for four locations in the Richmond river basin, while the Monitoring River Health Initiative dataset includes targeted observation from 31 sites with data collected six monthly.
New South Wales Office of Water dataset (Dataset 2)
The NSW Office of Water has a very large database of water quality data collected over many years and includes data collected at locations in the Richmond river basin. The types of water quality parameters collected in the Richmond river basin are extremely diverse (e.g. nutrients, temperature, and aquatic biota) but the three most commonly reported parameters are electrical conductivity (>2900 readings), pH (>2200 readings) and turbidity (>1890 readings). The locations where electrical conductivity was measured, the number of samples collected and their mean, minimum and maximum values are shown in Table 11. Matching analysis for pH and turbidity readings is shown in Table 12 and Table 13, respectively.
The Australian and New Zealand Guidelines for Freshwater and Marine Water Quality sets acceptable levels for electrical conductivity in the upland and lowland rivers of NSW catchments at between 30 and 350 µS/cm, and 125 and 2200 µS/cm, respectively. Mean values for the Richmond river basin fall within this range however maximum values exceed these ranges at times. Higher electrical conductivity values in the lowland areas are likely to reflect tidal influences in the lower reaches of the Richmond River.
Table 11 Sampling locations, gauge number, number of samples collected and mean, maximum and minimum electrical conductivity measurements for the Clarence‑Moreton bioregion
The Australian and New Zealand Guidelines for Freshwater and Marine Water Quality sets acceptable pH in the upland and lowland rivers of NSW catchments at between 6.5 and 7, and 6.5 and 8, respectively. Mean values are at times outside of these values and maximum and minimum values often sit outside of the guideline values.
Table 12 Sampling locations, gauge number, number of samples collected and mean, maximum and minimum pH measurements for the Clarence‑Moreton bioregion
The Australian and New Zealand Guidelines for Freshwater and Marine Water Quality sets acceptable levels for turbidity in the upland and lowland rivers of NSW catchments at between 2 and 25 NTU (Nephelometric Turbidity Unit), and 6 and 50 NTU, respectively. Mean values for the Richmond river basin fall within these ranges however maximum values exceed these ranges at times.
Table 13 Sampling locations, gauge number, number of samples collected and mean, maximum and minimum turbidity measurements for the Clarence‑Moreton bioregion
There is a lack of data on the presence of hydrocarbons as a result of coal mining and CSG operation and development. These data are important for reasons outlined in Section 126.96.36.199.
ANZECC/ARMCANZ (2000) National Water Quality Management Strategy: Paper No 4 - Australian and New Zealand guidelines for fresh and marine water quality: Volume 1 – The Guidelines. Australian and New Zealand Environment and Conservation Council and Agriculture and Resource Management Council of Australia and New Zealand, Commonwealth of Australia, Australia.
Rassam D, Raiber M, McJannet D, Janardhanan S, Murray J, Gilfedder M, Cui T, Matveev V, Doody T, Hodgen M and Ahmad ME (2014) Context statement for the Clarence-Moreton bioregion. Product 1.1 from the Clarence-Moreton Bioregional Assessment. Department of the Environment, Bureau of Meteorology, CSIRO and Geoscience Australia, Australia. Viewed 20 July 2015, http://data.bioregionalassessments.gov.au/product/CLM/CLM/1.1.
Turak E, Hose G and Waddell N (2000) Australia-wide Assessment of River Health: New South Wales Bioassessment Report (NSW Final Report), Monitoring River Health Initiative Technical Report no 2a, Commonwealth of Australia and NSW Environment Protection Authority, Canberra and Sydney.
Dataset 1 NSW Department of Environment and Heritage (2009) NSW Department of Environment and Heritage Historic Water Quality Data. Bioregional Assessment Source Dataset. Viewed 23 March 2015, https://data.bioregionalassessments.gov.au/datastore/dataset/4c5f7318-2567-4614-aa35-46aa0eb045f2.
Dataset 2 NSW Office of Water (2013) NSW Office of Water Surface Water Quality Extract 28_nov_2013. Bioregional Assessment Source Dataset. Viewed 23 March 2015, https://data.bioregionalassessments.gov.au/datastore/dataset/21234479-eabe-46f9-8af5-9f30847a18ba.
Dataset 3 NSW Office of Water (2015) Richmond stream gauge data. Bioregional Assessment Source Dataset. Viewed 23 March 2015, https://data.bioregionalassessments.gov.au/datastore/dataset/03f59f6b-8d06-4513-b662-db7c4c2d2909.