Annual water quality reports

ORC is responsible for managing Otago’s surface water resources. We undertake a long-term State of the Environment (SoE) monitoring programme which measures the state and trends in water quality across an extensive network of river and lake sites.

Our annual reports are based on the latest 5 years of monitoring data and summarise the current state of water quality across the region.

State & Trends of Rivers, Lakes & Groundwater Reports

We carry out research and technical water quality testing to ensure ecosystem health.

State and Trends of Rivers, Lakes, and Groundwater in Otago 2017-2022

May 2023

PDF | 8 MB

State and Trends of Rivers, Lakes, and Groundwater in Otago 2017 – 2022

PDF | 8 MB

State and Trends of Lake and River Water Quality in the Otago Region 2000 - 2020

PDF | 6 MB

Review of water quality and ecological data for the Manuherikia River catchment 2019

December 2019

PDF | 3 MB

NIWA was engaged by Otago Regional Council (ORC) to provide an assessment of selected water quality and ecological data for the Manuherikia River catchment in Central Otago. This study confirms that the information analysed provides an effective benchmark against which future ecological condition assessments of catchments can be compared.

Water Quality Study Waiwera River Catchment 2017

June 2017

ISBN 978-0-908324-41-5

PDF | 2 MB

This study found that water quality within the Waiwera catchment shows elevated concentrations of nutrients and bacteria that generally exceed the Schedule 15 limits/targets set out in Otago’s Regional Plan: Water. These elevated nutrient concentrations are sufficient to cause prolific algae growth. No discernible trends were found in the catchment’s State of Environment monitoring data set (2006 to 2017), other than the concentration of total phosphorus declined significantly during this period. An accumulation of fine sediment within the catchment’s waterways appears to be behind the dramatic reductions in abundance and diversity of macroinvertebrate communities and fish populations, particularly in the mainstem of the Waiwera River. Appropriate mitigation measures need to be implemented to protect the river from further degradation and to aid recovery.

State of Environment Report 2006 - 2017

PDF | 5 MB

Water quality study - Cardrona River catchment 2016

April 2016

ISBN 978-0-908324-30-9

PDF | 10 MB

The Otago Regional Council is responsible for managing Otago’s groundwater and surface-water resources. ORC carries out regular and extensive long-term monitoring as part of its State of the Environment (SoE) programme and carried out a targeted, short-term monitoring investigation of the Cardrona River in 2004-2005. This study repeated this work ten years later.

Water quality and ecosystem health in the Lake Tuakitoto catchment

November 2014

ISBN 978-0-478-37682-1

PDF | 1 MB

Lake Tuakitoto is a large freshwater wetland situated in the lower Clutha River catchment in South Otago. Much of the catchment consists of intensively grazed pasture with some scrub, and plantation forestry. There has been intensification of land use in the catchment which has the potential to affect water quality in the lower part of Lovells Creek and Frasers Stream.

Water quality in the Lindis River catchment 2016

January 2016

ISBN: 978-0-908324-26-2

PDF | 1 MB

The Lindis River is a major tributary of the upper Clutha River. There is heavy demand for water abstraction in the lower catchment. This report updates earlier studies to review the impact of changes in land use on the river catchment.

Shag River/Waihemo catchment: water quality and ecosystem

November 2014

ISBN 978-0-478-37681-4

PDF | 1 MB

The Shag River/Waihemo is a small river flowing from the slopes of Kakanui Peak and flowing in a south-easterly direction past the township of Palmerston before entering the Pacific Ocean just south of Shag Point/Matakaea. Most of the catchment consists of agriculture and forestry with some short-rotation cropping in the lower catchment. The objectives of this report are to: • Provide a baseline of water quality in the Shag River/Waihemo catchment, including at unimpacted (reference) sites, • Compare water quality in the Shag River/Waihemo catchment to water quality limits set out in Plan Change 6A, • Identify any patterns in water quality in the Shag River/Waihemo catchment and to relate these to land-use activities, where possible

Water quality in the Tokomairiro catchment: Trends and comparison with water quality standards

November 2013

ISBN 978-0-478-37666-1

PDF | 1 MB

This study examines how water quality has changed at a range of locations in the catchment over the past 12 years, and how present water quality compares with Plan Change 6A limits.

Waianakarua water quality report

October 2013

ISBN: 978-0-479-37667-8

PDF | 828 KB

The objectives of this report are to: • provide a baseline of water quality in the Waianakarua River catchment, including at unimpacted (reference) sites • compare water quality in the Waianakarua catchment to water quality standards set out in plan change 6A • identify any patterns in water quality in the Waianakarua catchment and to relate these to land-use activities, where possible.

Tokomairiro catchment report card 2011 to 2012

November 2012

PDF | 1 MB

The Tokomairiro catchment is dominated by intensive farming. The monitoring programme which ran from August 2011 to April 2012 sought to identify pollution hotspots, and appropriate strategies to better manage water quality.

Kakanui River Water Quality Report

June 2013

ISBN 978-0-478-37660-9

PDF | 3 MB

The Otago Regional Council (ORC) is responsible for managing Otago’s groundwater and surface-water resources. Although the ORC carries out regular and extensive long-term water quality monitoring as part of its State of Environment (SOE) programme, it has not carried out a targeted short-term monitoring investigation in the Kakanui River catchment.

Water quality and ecosystem health in the Upper Taieri

September 2012

ISBN 978-0-478-37651-7

PDF | 2 MB

This report provides the results from a more detailed, short-term investigation carried out in the Upper Taieri River catchment.

Water quality and ecological health for the Catlins area

November 2011

ISBN 978-0-478-37617-3

PDF | 785 KB

This report provides the results from one of the more detailed investigations carried out on water quality in the Catlins area.

Effects of land use on water quality in the Pomahaka catchment

April 2011

ISBN 978-0-478-37608-1

PDF | 2 MB

This report provides the results from one of these more detailed investigations carried out in the Pomahaka River catchment. The investigation was implemented to more accurately understand how different land-uses can affect water quality and in-stream ecological values.

Water quality and ecosystem health in the Manuherikia catchment

September 2011

ISBN 978-0-478-37619-7

PDF | 1 MB

The Otago Regional Council (ORC) carries out regular water quality monitoring as part of its State of Environment programme, as well as short-term targeted water quality monitoring programmes. This report provides the results from a more detailed, short-term investigation carried out in the Manuherikia River catchment between 2009 and 2011.

Pomahaka water quality summary report

March 2011

PDF | 146 KB

In December 2008, the Otago Regional Council (ORC) initiated an intensive investigation into water quality and ecological health in the Pomahaka River catchment, south-west Otago.

Patterns of water quality in the Pomahaka Catchment 2010

May 2010

PDF | 402 KB

ORC conducted a 12-month water quality sampling programme, with the aim of getting a better understanding of the effects of land use on water quality in the Pomahaka catchment.

Otago lakes trophic status November 2009

November 2009

ISBN 1-877265-85-3

PDF | 3 MB

This report provides the results from short-term studies, which monitored the health of five high country lakes ( Hayes, Johnson, Onslow, Wakatipu, and Wanaka). ORC and local communities can use this information to work together to ensure the wellbeing of these five important lakes.

Surface water quality : the Water of Leith and Lindsay Creek

August 2008

ISBN 1-877265-67-5

PDF | 734 KB

To help protect water quality, ORCcarries out longterm water quality monitoring as part of a State of the Environment programme. To supplement this information, targeted and detailed short-term monitoring programmes are also implemented in some catchments. This report provides the results from more detailed investigations carried out in three catchments: Water of Leith, Kaikorai Stream, Waitati River and Carey’s Creek

The effect of irrigation runoff on water quality

May 2006

ISBN: 1-877265-40-3

PDF | 2 MB

This report outlines results of a surface water quality monitoring programme carried out in tributaries of the Manuherikia, Taieri, and Waitaki rivers.

Didymo in Otago: a summary

July 2007

PDF | 513 KB

This report has been written to summarise the biology, ecology, and impacts of didymo in the Otago context. It presents the results of a monitoring programme on the Fraser River, and photographic monitoring studies from the Clutha River/Mata-Au, Hawea, and Fraser Rivers.

Water quality in the Lindis and Cardrona rivers

May 2006

ISBN: 1-877265-38-1

PDF | 1 MB

A monthly water quality monitoring programme was carried out between September 2005 and March 2006 at six sites on the Cardrona River and nine sites on the Lindis River. Water was tested for a range of physico-chemical and microbiological parameters. This report provides more detailed information than that gathered for the State of Environment programme, which has been undertaken since the late 1980's.

Waiareka Creek and Island Stream report

May 2005

ISBN 1-877265-18-7

PDF | 4 MB

This report presents the results and findings of a water quality monitoring programme undertaken in the Island Stream and Waiareka Creek catchments between September 2004 and March 2005.

Surface water quality in south-west Otago

June 2004

ISBN 1-877265-15-2

PDF | 1 MB

This report presents the results and findings of three water quality monitoring programmes undertaken in the Waipahi and Pomahaka catchments between April 2000 and May 2003.

Lake Waipori and Lake Waihola report

March 2005

ISBN 1-877265-17-9

PDF | 1 MB

A two-year trophic level investigation of Lakes Waipori and Waihola was carried out between October 2002 and October 2004 to gain a better understanding of the two lakes' nutrient status.

Lower Taieri River catchment report

March 2004

ISBN 1-877265-32-2

PDF | 3 MB

This report presents the results and findings of the 12-month Lower Taieri monitoring programme, including routine state of the environmental biological monitoring in the lower Taieri River catchment.

Upper Taieri River catchment report

March 2003

ISBN 1-877265-30-6

PDF | 2 MB

This report presents the results and findings of a 14-month monitoring programme. Information is also drawn from ORC’s long-term State of the Environment monitoring sites, principally those located at Stonehenge (Hore's Bridge) and Halls Bridge.

Water quality reports for Land and Water regional plan

Memo Nitrogen limits and their impact within Otago region

November 2023

PDF | 482 KB

This memo addresses whether to retain a nitrogen limit for pastoral farming systems and the suitability of implementing such limits for vegetable growing and arable production.

Catlins LWRP Report Summary

October 2023

PDF | 644 KB

Dunstan Rohe Science Summary

PDF | 935 KB

Environmental impacts of different land uses - A brief review of published literature

August 2023

Dengg, Markus; Button, Eric

PDF | 1 MB

Science approach to development of GMP and GMP plus land use scenarios - updated

June 2022

PDF | 657 KB

Memorandum Test of revised periphyton nutrient criteria for Otago and Southland Regions

November 2023

PDF | 406 KB

Proposed nutrient load limits for Otago estuaries

August 2021

2021256CH

PDF | 4 MB

Assessment of Escherichia coli Load Reductions to Achieve Freshwater Objectives in the Rivers of Otago

October 2021

PDF | 2 MB

Memorandum: Achievement of NPS-FM 2020 suspended sediment attribute bands for the Otago stream network

August 2023

PDF | 3 MB

Assessment of Nutrient Load Reductions to Achieve Target Attribute States in the Rivers, Lakes and Estuaries of Otago

October 2023

PDF | 8 MB

Review - Mitigations for minimising nutrient loss from farming systems

November 2022

PDF | 366 KB

Summary outlining the current SoE trends and general environmental impacts in areas of vegetable growing

August 2023

PDF | 159 KB

Memo GMP and GMP+ reduction magnitude relative to network target attribute states for periphyton nutrient criteria 2024

February 2024

PDF | 3 MB

Manuherekia Rohe (Clutha/Mata-Au FMU) River Water Quality State and Trends

April 2021

PDF | 1 MB

PDP advice on onsite wastewater systems to support development of a new planning framework

August 2023

PDF | 538 KB

Shag River Catchment Luciag Report 2023

April 2023

PDF | 2 MB

Suggested Primary Contact Sites Using 2018 Survey Data

July 2023

XLSX | 441 KB

Memo - Aggregate Trends for Otago Region 2024

March 2024

PDF | 560 KB

Memo - Comparison of Threshold Values to Reference Condition Feb 2024

February 2024

PDF | 359 KB

Memo - LWRP Surface Water Quality Programme Regional Summary 2024

February 2024

PDF | 186 KB

Authors: Jason Augspurger and Tom Dyer

Memo - TN, TP, E. Coli and Sediment FMU Overall Summary 2024

February 2024

PDF | 276 KB

Author: Jason Augspurger

Water Quality Baseline State Report 2024

February 2024

PDF | 3 MB

Report writer: Jason Augspurger

LWRP Nitrogen and Phosphorus Reduction Scenarios March 2024

March 2024

PDF | 14 MB

Many of New Zealand’s freshwater environments are under pressure from land use intensification resulting in deteriorating water quality and ecosystem health. As a result, limits must be set on resource use to achieve receiving environment water quality objectives such as the health of rivers, lakes, and estuaries. To aid communities in determination of desired level of ecosystem health, a model is needed which can fill the knowledge gap on required emission reductions to achieve target attribute states and whether different mitigation suites (GMP and GMP+) may achieve the desired reductions. Report writer: Jason Augspurger

Upper Lakes Rohe (Clutha/Mata-Au FMU) River & Lake Water Quality State and Trends

April 2021

PDF | 2 MB

This study analysed the available water quality data in upper Clutha/Mata-Au lakes and their tributaries.

Science memo - Sediment issues from forestry in Otago

February 2024

PDF | 249 KB

This memo presents known information about the sediment issues from plantation forestry in Otago.

Dunedin & Coast Science Summary

October 2022

PDF | 550 KB

Dunstan - Earnscleugh Groundwater Basin Model - Conceptual model

May 2022

C02577507

PDF | 5 MB

Dunstan - Earnscleugh Groundwater Basin - Model results and scenarios

March 2023

C02577507

PDF | 6 MB

North Otago LWRP Report Summary

November 2023

PDF | 747 KB

Lower Clutha Science Summary

November 2022

PDF | 656 KB

Options for improving water quality within the Otago region: Development of GMP & GMP+ scenarios project report

November 2022

PDF | 2 MB

ORC mitigation framework model

November 2021

PDF | 1 MB

Mitigation options to reduce nutrient loss in the Otago Region

January 2023

PFR SPTS No. 23350

PDF | 856 KB

Overview Of Proposed Catchment Management Approach 2021

February 2021

PDF | 4 MB

Review Of Mitigation Modelling And Assumptions

January 2023

PDF | 212 KB

Roxburgh Rohe Science Summary

November 2022

PDF | 708 KB

Technical note: Implementing the Otago LWRP GMP+ scenario in SedNetNZ

August 2022

PDF | 3 MB

SedNetNZ modelling for freshwater planning in Otago

August 2022

PDF | 4 MB

Taieri LWRP Science Report Summary

October 2022

PDF | 985 KB

Upper Lakes Rohe science Summary

October 2022

PDF | 3 MB

Page last updated 13 July 2024.