Quality
What We Monitor and Why?
Rivers and Streams
Rivers and streams are important resources in Southland and are highly valued by people for a range of reasons, including as a source of food and drinking water, a means of disposing of waste water, energy for hydroelectric power, and a place for recreation. Increasingly, the environmental values of rivers and streams, the diverse ecosystems and life they sustain, are being recognised as well.
The health of rivers and streams is influenced by natural factors, such as climate, soil and rock type. However, human activities also play a major role, particularly what people are putting into the water, via both direct discharges and run-off from land, affecting the quality.
Environment Southland runs two programmes; water quality monitoring and bio-monitoring. We monitor water quality at 71 sites, in 41 rivers and streams in Southland. Sites are visited monthly and samples/measurements are taken for both the physical properties of the water, such as, pH, temperature, and visual clarity, and the chemical characteristics, such as, nutrients and dissolved oxygen. The bio-monitoring programme involves monitoring the ecological health of our rivers at 79 sites annually during summer. We measure the amount and type of benthic periphyton (algae on the bottom of the river bed) and the macroinvertebrates (e.g. insect larvae, worms and snails).
When the results from the water quality monitoring and bio-monitoring programmes are combined, they indicate the overall health of a stream. Analysis of the data, including comparison against national and regional water quality standards and targets (see Regional Water Plan) enables us to determine any short-term changes and long-term trends in the quality of the water and the nature of any contaminants present, so that we can try to fix any problems.
Water Quality Biomonitoring SitesLakes and Lagoons
Southland contains several large, iconic lakes that are valued highly by people for aesthetic, cultural, recreational and economic reasons. Their unique ecological values are also important for sustaining land and water-based life. Pressures exist on many of our lakes and lagoons, from the intensification of surrounding land use, lake side communities and hydroelectric power. Waituna Lagoon located in Awarua, Southland, is both nationally and internationally significant. The lagoon was one of the first sites in the world to be named "a wetland of international significance" under the RAMSAR Convention.
Environment Southland regularly monitors indicators of water quality in Lake Te Anau, Lake Manapouri and Waituna Lagoon. In addition, spot sampling of water quality has occurred in a number of small, coastal lakes (i.e. Lake Vincent, Lake George, Forest Lake and the reservoir).
From Feb 2000 to July 2007 samples were collected every month in Lake Te Anau (2 sites) and Lake Manapouri (three sites), but since July '07 monitoring has been conducted quarterly due to the excellent quality of water. Both lakes are considered natural state waters and have very clean water. In terms of water quality, they are in the top 10% of lakes monitored in New Zealand. Four sites in Waituna Lagoon have been monitored monthly since Aug 2003 (with earlier monitoring at the East site since Oct 2001). Since March 2011 there have been changes to the monitoring regime, with increased sampling occurring when the lagoon closes off from the sea. Click here for more on our work in Waituna Lagoon.
Water quality results from our lakes and lagoons are also compared against national guidelines/standards, and the council's Regional Water Plan water quality standards and targets.
Map of Lakes Monitored by Environment SouthlandData
Water quality data for rivers, streams, lakes and lagoons is not currently available on this website, but can be obtained by contacting Environment Southland’s Water Quality Scientist. Environment Southland is developing a graphical function which will enable data to be displayed online.
Water Quality Reports
Environment Southland is the brand name of Southland Regional Council.