The Otago Regional Council (ORC) today received a significant state of the environment report on river and lake water quality in the region.

The study reports on the state of water quality on a site-by-site basis, relative to nationwide targets specified in the National Policy Statement for Freshwater Management 2020. It also assesses water quality trends at each site where there is sufficient data, and across Otago as a whole.

The report considers 10 water quality variables and indicators at over 120 monitoring sites in Otago: 110 river sites, and 22 sites and depths at nine lakes.

General Manager Strategy, Policy and Science Gwyneth Elsum said the information in the report was valuable for ORC and the wider community as it updates our knowledge of water quality across Otago.

“This report largely reflects the patterns we have seen in the past, which tell us that water quality is best in the headwaters and at higher elevations, but it suffers at sites in smaller, low-elevation streams that drain pastoral or urban catchments.

“That spatial pattern of water quality in Otago will inform the development of our new Land and Water Regional Plan, which divides the region by catchment into freshwater management areas.

“This information will also support ORC and the community to implement other water quality improvement initiatives,” Ms Elsum said.

The report does not analyse the drivers for water degradation trends, due to the lack of detailed information that ORC currently holds on land use and land management changes at a local or catchment scale. ORC recently formed a new science team to develop its knowledge in this area.

The ‘State and Trends of River and Lake Water Quality in the Otago Region 2000-2020’ report can be viewed online at https://www.orc.govt.nz/plans-policies-reports/reports-and-publications/water-quality/research-and-technical-reports

The analysis in today’s report will be repeated next year with data up until June 2022, to give ORC a clear baseline to evaluate the effectiveness of its upcoming Land and Water Regional Plan in the future.