The quality of the waters in our rivers and aquifers is naturally influenced by inputs of salt and nutrients from the surrounding landscape and its geology. However, water quality can also be degraded by a wide range of factors including point source activities such as sewage discharge and mine wastes, and diffuse source activities such as land clearing and cultivation, urban and agricultural development.
The regulation of river flow by major storages and weirs and the extraction of water have also influenced the quality of water with many rivers receiving fewer flow events and floods which naturally clean and flush the river. While lowered water quality may only be a short–term problem for rivers, water in our groundwater systems has often been stored for thousands of years so any contamination has long-lasting impacts.
At a national level, the National Water Quality Management Strategy provides guidance on water quality planning and management and establishes guideline values for various water quality measures. In NSW, interim water quality objectives have been established in consultation with the community that help decision makers consider water quality in both big picture strategic planning such as Catchment Action Plans and Regional Strategies, and at the local level when assessing impacts of developments.
The Office of Water, through its water licences, also requires that contaminated irrigation or mining water not be returned directly to rivers and groundwater. The Office of Environment and Heritage licenses the discharge of sewage and other point source pollution.
The NSW Office of Water received funding from the Bureau of Meteorology under the 2010-2011 Modernisation and Extension of Hydrologic Monitoring Systems Program to undertake a surface water quality database revitalisation project (4NSW01.18). This project was to review, update and improve the quality assurance procedures and certification of historical water quality data and associated station metadata. It also ensured that all data would meet national standards being developed by the bureau. This will in turn improve accessibility to water quality data by Office of Water, state and federal agencies, local government, industry and the community.
This report documents the process of data revitalisation that occurred prior to and through the migration of historical data from the departments historical database TRITON through to the new database KiWQM. It has led to improved standard of water quality data stored by the NSW Office of Water, increased access to historical water quality data, formalised procedures for data entry and management and improved data management systems. The project has also enhanced staff capacity building and improvement in the ability of the Office of Water to provide quality standards of historical data and ensure future data integrity.
The Office of Water is committed to improving its standards in data management and this data revitalisation and station detail recovery project provided significant improvements in the water quality data that compliments the development of the new system (KiWQM) by ensuring the quality of the historic data to be imported into it.
The work initiated through this project is still progressing and the key recommendations identified have been developed into an ongoing work program for the future. This is particularly important in progressing NSW water quality data management and quality assurance.
Read the report Surface water data revitalisation project BOM4NSW1.18 - final project report (PDF 4.7 MB).
The NSW Office Water is trialling new technology to provide real-time monitoring of potential blackwater events in flood conditions in southern parts of the state.
Blackwater is a natural event and can occur during times of drought or floods. It involves decaying organic matter that uses oxygen and then darkens the water. This places stress on fish and other aquatic biota, potentially leading to fish kills. During floods in the Murrumbidgee River in late 2010-early 2011, following a long period of drought, several severe blackwater events led to fish kills and periods of total lack of oxygen in water returning to the river from the floodplain. A study of these events and the use of environmental releases indicated that active management by dilution may successfully reduce risks of blackwater events.
- Murrumbidgee blackwater monitoring. Blackwater management using environmental water allowance – November 2010 to March 2011 (PDF 1.59 MB)
The technology is being used at ten telemetered gauging stations in the Edward, Niemur and Wakool rivers, Little Merran and Merran creeks, the Darling River at Burtundy and the Murrumbidgee River at Balranald.
The aim of the project is twofold. Firstly, to provide an early warning system for dropping oxygen levels so that water managers can better control water quality impacts to minimise stress to aquatic life and minimise fish mortality. The sensors will obtain continuous dissolved oxygen readings at strategic sites in the Riverina as well as end of valley sites for the Murrumbidgee and Darling rivers. The data will also greatly improve the modelling capabilities of blackwater events by providing better datasets and measuring river health.
Secondly, the project will benefit water users especially during crisis events such as when blackwater occurs and in drought conditions when aquatic biota is subject to oxygen related stress. The sensors have shown a drop in dissolved oxygen levels in some river systems as a result of flooding and are being used to monitor the recent flooding and its recession.
The installation of the sensors at hydrometric sites commenced in December 2011. During the major flood events of March – April 2012, the network supplied critical real time dissolved oxygen information. The NSW Office of Water provided a daily circular to assist incident management by state and federal agencies. The site data was also posted on the Office of Water's monitoring website. This information helped the group plan water releases to moderate the effects of the blackwater event. The Office of Water and its staff received high praise from other agencies for this innovative project and the efficient, timely supply of information to assist incident management.
"From our River Murray system operational perspective, the regular dissolved oxygen updates have assisted immensely with river ops decisions as well as planning and coordination aspects. Well done everyone involved!" – River Management, Murray-Darling Basin Authority.
"This was valuable intelligence in guiding our event planning and real time operations. Effort well spent, thanks!" – Environmental Water Delivery, Office of Environment and Heritage.
The trial results are now being reviewed and options developed for expansion of these early warning networks in other areas of the state.
The NSW Office of Water has a number of programs that assess water quality and try to improve it. One such program, the Namoi Water Quality Project, commenced in July 2002 and ran for a period of five years.
Basic water quality attributes were monitored on a monthly basis at a total of 29 sites. Monitoring of agricultural chemical residues was undertaken at sites located in the main dryland and irrigated cropping areas of the Namoi valley.
Results indicate that good agronomic practices in conjunction with the management of riparian vegetation to reduce stream bank erosion provide simple and effective means to improve water quality in the long term.
Read the final report Namoi Water Quality Project 2002-2007 (PDF 1.5 MB).
Waterwatch NSW is a community based program in water quality monitoring. The aim of the program is to have the public and local organisations involved in regular water quality monitoring activities to inform government, the community and natural resource management organisations on the health of our local waterways.
To assist Waterwatch groups, the Office of Environment and Heritage in partnership with the Commonwealth Government developed new resource material and a new Waterwatch database for users which were released in 2010. These resources include manuals, guides and posters that can assist groups in the field on water quality sampling methods and techniques.
The Waterwatch database allows Waterwatch groups to enter water quality monitoring results from their local area or chosen site. The information is then used by Local Land Services and other organisations to develop an indication of water quality health in a particular area. The information collected may also provide an indication of upstream health and what other factors may be impacting the health of a lake, river or estuary.