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Technical documents

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Updates

Summary of technical projects (August 2015) [PDF, 446 KB] 

Reports

Reports are published here as soon as they are approved. The documents below include:

  • reports commissioned by the Technical Leaders Group (core part of the Technical Alliance) for Healthy Rivers/Wai Ora
  • reports not commissioned by the Technical Leaders Group, but which they have reviewed for the project.

The reason for classing reports as ‘draft for discussion’ is that it's envisaged they will be published as Waikato Regional Council technical reports in the future.

Document About the document
Groundwater
Groundwater resource characterisation in the Waikato River catchment for Healthy Rivers Project  [PDF, 12 MB] TR 2018/33. Describes the models of geology and water budgets developed by GNS Science and used, with groundwater chemistry data, to characterise groundwater systems.
Estimation of lag time of water and nitrate flow through the Vadose Zone: Waikato and Waipa River Catchments [PDF, 12 MB] TR 2018/31. Presents a methodology and results for predicting the time taken for nitrate to travel from the landsurface, though the unsaturated (vadose) zone and into shallow groundwater.
Review of historical land use and nitrogen leaching: Waikato and Waipa River catchments [PDF, 11 MB] TR 2018/35. Describes an assessment of nitrogen leaching losses likely to prevail in the Waikato and Waipa River catchments.
Groundwater field investigations over the 2014-15 summer in support of the Healthy Rivers Project [PDF, 4.1 MB] TR 2018/32. Describes short term groundwater related field investigations undertaken in summer 2014-15 to support Healthy Rivers/Wai Ora. 
Prediction of Subsurface Redox Status for Waikato Healthy Rivers - Plan for Change: Waiora He Rautaki Whakapaipai Project [PDF, 2 MB] TR 2018/34. Provides predictions of the subsurface redox status of shallow and medium depth groundwater in the Waikato and Waipa river catchments.
Summary of ground water information for consideration by the Collaborative Stakeholder Group [PDF, 4.7 MB] TR 2018/37. Provides a summary of investigations and main conclusions of six studies undertaken to provide an understanding of groundwater resources, and groundwater age and nitrogen attenuation processes in the 74 subcatchments of the Waikato and Waipa river catchments.
Short term field investigations of groundwater resources in Waipa River Catchment - January to April 2015 [PDF, 19 MB] TR 2018/36. Details an investigation into groundwater resources in the Waipa catchment, to enhance understanding of groundwater systems in the catchment.
Surface water (including attributes)
A methodology for chlorophyll and visual clarity modelling of the Waikato and Waipa Rivers [PDF, 2 MB] TR 2018/60. Describes the methodology used to estimate changes in chlorophyll concentrations and visual clarity in the Waikato and Waipa Rivers in response to changes in nutrient concentrations and sedimentl oads under various scenarios of land management and land use change.
Waikato River suspended sediment: loads, sources and sinks [PDF, 1.2 MB] TR 2018/65. Reviews and presents information on the suspended sediment loads, the importance of river bank erosion, and the role of hydro‐reservoir sediment trapping within the Waikato and Waipa River systems.
Extracting NZeem-estimated sediment yield data for Agribase farm boundaries within HRWO catchments [PDF, 1.4 MB] TR 2018/61. Provides methodology, data layers and assumptions used to produce a map of farms and identify their farm ID, sediment load and subcatchment to which each farm drains.
Modelling E. coli in the Waikato and Waipa River Catchments - Development of a catchment-scale microbial model [PDF, 2.1 MB] TR 2018/62. Presents three models developed to provide input data to a farm cost model to evaluate the costs associated with mitigating farm practices to reduce E. coli loads.
Refined classification of land characteristics to assist economic modelling [PDF, 4.3 MB] TR 2018/64. Focuses on spatial characterisation of key drivers of contaminant loss, such as land use, slope and rainfall, and the distribution of combinations of these drivers.
Sources of faecal pollution in selected Waikato rivers - July 2015 [PDF, 609 KB] Assesses water quality in five streams in Waikato for E. coli concentration and for the source of faecal pollution. 
Modelling nutrient loads in the Waikato and Waipa River Catchments [PDF, 1.4 MB] TR 2018/63. Provides a description of two nutrient load models developed to provide technical input data to the economic model, including model inputs and calibration data and methods used to determine median nutrient concentrations and annual loads.
Water Quality Attributes for Healthy Rivers - Wai Ora Plan Change [PDF, 1.4 MB] TR 2018/66. A summary of the process undertaken to define a suite of relevant attributes for waters in the Waikato and Waipa River catchments. 
Nitrogen, phosphorus, and chlorophyll a relationships
Waikato River Bioassay Study 2013-14 - Assessment of nutrient limitation [PDF, 4.1 MB] Presents findings of a series of monthly bioassay studies to assess possible nutrient limitation and zooplankton grazing effects in the Waikato River.
Factors influencing chlorophyll a concentrations in the Waikato River - Drivers of phytoplankton production in Lake Karapiro [PDF, 4.8 MB] Presents findings of a series of bioassay studies run in Lake Karapiro under different flow conditions from 5 locations along the lake to assess the effects of retention time and thermal stratification in the hydro lakes on chlorophyll a concentrations in the Waikato River.
Assessment of Waikato River nutrient limitation - Peer reviewed key findings of WRC and DairyNZ studies [PDF, 1 MB]

TR 2018/43. Reflects a caucusing session on key findings and points of disagreement on the above two reports.
Nutrient reduction bioassays in the Waikato River [PDF, 1.7 MB] TR 2018/45. Presents results of a nutrient reduction bioassay undertaken on Waikato River water, to determine whether reducing either N or P concentrations would cause a reduction on phytoplankton growth.
Nutrients and phytoplankton (chlorophyll a) in the Waikato River [PDF, 2.5 MB] TR 2018/46. Summarises studies that address relationships between N, P and algae in the Waikato River system, to enhance understanding of how algal growth responds to, and might be controlled by N and P.
Nutrient limitation of algal biomass in the Waikato River [PDF, 5.5 MB] TR 2018/44. Aims to improve understanding of the relationships between algal biomass and nutrients in the Waikato River, by an in depth analysis of the water quality data collected monthly by Waikato Regional Council at 10 sites along the river.
Scenario modelling
Scenario modelling report - first round of scenarios [PDF, 3.5 MB]

Economic evaluation of first set of scenarios for water quality improvement in the Waikato and Waipa River catchments.
Scenario modelling report - second round of scenarios [PDF, 6.2 MB] Economic evaluation of second set of scenarios for water quality improvement in the Waikato and Waipa River catchments.
Description of mitigation options defined within the economic model for Healthy Rivers Wai Ora Project [PDF, 2.3 MB] TR 2018/47. Describes mitigation options defined within the economic model for Healthy Rivers/Wai Ora.
Memo to TLG on Point Sources [PDF, 153 KB] Reports on additional information obtained from the operators of municipal and industrial point source sites, in relation to report 4.10  (below) Municipal and industrial water values in the Waikato River catchment.

Municipal and Industrial Water Values in the Waikato River Catchment (OPUS Point Source Report) [PDF, 1.3 MB]

Identifies entities with controlled discharge rights and their actual level of discharge, assesses treatment costs, and the costs and reduced contamination expected under five different treatment scenarios.
General principles underlying the development of the Healthy Rivers Wai Ora (HRWO) economic model [PDF, 870 KB] TR 2018/50. Outlines the reasons why certain key decisions have been made during the design and development of the Healthy Rivers/Wai Ora economic model used to predict size and distribution of abatement costs for different scenarios.
Economic Impacts of the Healthy Rivers Initiative - Freshwater Management Unit, Regional and National Assessment [PDF, 1.4 MB] TR 2018/48. Describes the methodology used for assessing freshwater management unit, regional and national scale economic impacts of various scenarios .
Model structure for the economic model utilised within the Healthy Rivers Wai Ora process - an overview of the model structure [PDF, 789 KB]

TR 2018/52 - Volume 1. Outlines the structure of the Healthy Rivers/Wai Ora economic model utilised at the farm and catchment scale.
Identifying complementarities for the Dairy and Forestry Industries in the Central North Island [PDF, 1.5 MB] Provides evidence on the effects of land use using the dairy and forestry industries in the Central North Island as a case study. The study aims to provoke and promote constructive discussion on how complementarity opportunities can be generated at a land enterprise (farm or forest) and catchment level to create beneficial scenarios for both industries.
Land use conversion costs for Healthy Rivers Wai Ora Project [PDF, 842 KB] TR 2018/51. Provides assessments of land use conversion costs for a range of pastoral enterprises in the Waikato region.
Sheep and beef data adjusted for average schedule price and expenditure [PDF, 1.7 MB] TR 2018/58. Provides updated modelling data for sheep and beef farms using revised assumptions, as discussed in a Collaborative Stakeholders Group workshop.
Simulation of the proposed policy mix for the Healthy Rivers Wai Ora process [PDF, 1.1 MB] TR 2018/59. Simulates the Collaborative Stakeholder Group's policy mix under several different situations to assess its impact on economic and water quality outcomes in the Waikato and Waipa river catchments.
Prediction of water quality within the Waikato and Waipa River catchments in 1863 [PDF, 1.1 MB] TR 2018/54. Provides evidence around the state of water quality in the Waikato and Waipa river catchments in 1863.
Regional and national level economic impacts of the proposed Waikato Regional Plan Change 1 - Waikato and Waipa River Catchments [PDF, 704 KB] TR 2018/55. Describes the regional and national level implications of the policy mix associated with the plan change under several different situations.
Evaluation of scenarios for water-quality improvement in the Waikato and Waipa River catchments - Business-as-usual assessment [PDF, 731 KB] TR 2018/49. An outline of the potential implications of what would happen in the absence of the proposed Plan Change - predicting outcomes associated with moving forward in a “business as usual” scenario.
Evaluation of scenarios for waterquality improvement in the Waikato and Waipa River catchments - Assessment of second set of scenarios 24 September 2015 [PDF, 6.8 MB] TR 2018/57. The Healthy Rivers: Plan for Change/Wai Ora He Rautaki Whakapaipai (HRWO) project will establish targets and limits for nutrients (nitrogen and phosphorus), sediment, and E. coli in water bodies across the Waikato and Waipa catchments. As part of the process of establishing targets and limits, the Collaborative Stakeholder Group (CSG) asked for a technical assessment of four initial scenarios.
Economic evaluation of scenarios for water-quality improvement in the Waikato and Waipa River catchments - Assessment of first set of scenarios 24 August 2015 [PDF, 3.8 MB] TR 2018/56. The purpose of this report is to describe outputs from a predictive-modelling approach that aimed to identify the economic implications of altering land and point-source management to achieve the water-quality limits proposed for each of these scenarios. 
Mātauranga Māori and integrated assessment

Integrated assessment: baseline and scenarios [PDF, 573 KB]

 Assesses the social, cultural, economic and environmental effects on the wider community of changes required to meet water quality scenarios the Collaborative Stakeholder Group is exploring.
Mātauranga Māori knowledge networks [PDF, 1.7 MB] TR 2018/42. Reports factors affecting food gathering, swimming and special characteristics on the Waikato and Waipa Rivers and their tributaries from a Māori perspective.
Social impacts and trends analysis - a review of indicators and social impact trends for selected water quality plan changes [PDF, 553 KB] Provides an overview of social indicators, impacts and trends that have been considered as part of selected recent water quality plan changes and plan reviews throughout New Zealand.
Integrated assessment for the Healthy Rivers Wai Ora: the baseline information [PDF, 1.2 MB] Provides information about the people and the environment in the Waikato and Waipa river catchments, summarising the current cultural, economic, environmental and social situation.
Integrated assessment 1: Assessment of scenarios from modelling round one [PDF, 1.7 MB] TR 2018/40. Provides information on potential social, environmental, cultural and economic impacts if policy was put in place to restore and protect the Waikato and Waipa rivers.
Integrated assessment 2: Achieving water quality for swimming, taking food and healthy biodiversity [PDF, 1.3 MB] TR 2018/41. Summarises information on potential social, environmental, cultural and economic impacts if policy was put in place to restore and protect the Waikato and Waipa rivers.
Comment on employment and vibrant resilient communities indicators [PDF, 894 KB] TR 2018/39. Provides a review of the community resilience and labour market indicators proposed for use in monitoring the impact of the project on communities and individuals.
Baseline report [PDF, 1.6 MB] TR 2018/38. This report contains information about the people and environment in the Waikato and Waipa river catchments. It summarises the current cultural, economic, environmental and social situation. This is called ‘baseline information’.