1. The input of the Technical Leaders Group so far…
Presented to the Healthy Rivers Wai Ora Committee, 5th August 2014

2. Members of the Technical Leaders Group (TLG)
Bryce Cooper
Mike Scarsbrook
Liz Wedderburn
Tony Petch
John Quinn
Graeme Doole
Antoine Coffin
Formed late May, first meeting 5th June

3. Input to the Collaborative Stakeholder Group (CSG) to date
CSG #3 at Tokoroa – State and trends in water quality
CSG #4 at Te Kuiti – Approach to incorporating technical input into process
Answering a variety of queries posed by the CSG
Now:
Determining technical information needs and gaps
Preparing technical input for CSG#5

4. State and Trends in Water Quality
State – is it “good” or “poor”?
and
Trend – is it getting “better” or “worse”?

5. Project scope – the four contaminants
Relevance
Pathogens (E. coli)
Human health: swimming, waka ama, kai gathering, boating, angling etc
Cultural acceptability
Livestock health: drinking water
Domestic & industrial use: treatment needs
Sediment:
Suspended sediment
Water clarity
Turbidity
Aesthetics, safe swimming, waka ama, kai gathering, boating, angling
Ecosystem health (light, primary production, visual feeders - fish, birds)
Sedimentation: drainage/flooding, dam volume
Nutrients:
Nitrogen (TN, Nitrate, DIN) and Phosphorus (TP, DRP)
Promotes plant growth – e.g., nuisance blooms with aesthetic, toxic (cyanobacteria) and ecosystem health impacts
Nitrogen toxicity:
Ammonium & nitrate
Toxicity to aquatic life

6. Water quality monitoring network
Over 60 sites in Waikato/Waipa
Sampled regularly since 1992
Quality assured and reliable data

7. Current State – E. coli
Source: NIWA 2010 WRISS

8. Current State – Nitrogen
Source: NIWA 2010 WRISS

9. Sources of nutrients, Taupo Gates to Port Waikato

10. Rural sources of contaminants
NIWA 2010 WRISS report

11. Summary of Water Quality State – is it “good” or “poor”?
“Excellent in places, poor in others”
Upper Waikato main-stem excellent to good
Waipa main-stem often poor
Lower Waikato main-stem satisfactory to poor
Tributary streams range from poor to excellent
Lowland lakes very poor

12. State and Trends in Water Quality
State – is it “good” or “poor”?
and
Trend – is it “getting better” or “getting worse”?

13. ..is it “getting better” or “getting worse”?
Water Quality Trends..
..is it “getting better” or “getting worse”?
Two dimensions to trend analysis:
Direction of change – increasing or decreasing
Rate of change – slow or fast

14. A water quality record with a trend
Rate = +5.8% per year

15. Water quality trends at Waikato & Waipa River sites, 1993-2012
Better  Stable Worse

16. Summary of Water Quality Trends –
is it “getting better or worse”?
On a catchment-wide basis, from 1993 to 2012 there has been a:
Decrease in phosphorus (“better”)
E.coli mostly stable, some increases and some decreases
Increases in nitrogen and turbidity (“worse”)
Dairy expansion and intensification cause of much of the increases in nitrogen and turbidity
Improved wastewater treatment likely cause for decrease in phosphorus

17. Input to the Collaborative Stakeholder Group (CSG) to date
CSG #3 at Tokoroa – State and trends in water quality
CSG #4 at Te Kuiti – Approach to incorporating technical input into process
Answering a variety of queries posed by the CSG
Now:
Determining information needs and gaps
Preparing technical input for CSG#5

18. Healthy Rivers Policy Process
Approach – as the TLG see it
(aligned to NPS for Freshwater Management 2014)
Healthy Rivers Policy Process
Desired Values
Setting Attribute Levels
Water quality (N, P, Sed., bacteria) consistent with Desired Values
Scenario Analysis – looking at future options for limits on point and non-point losses from land that achieve attribute levels
Integrated assessment across Values to provide CSG with social, economic, cultural & ecological analysis
deliberations
CSG
CSG Focus Statement
e.g., safe to swim, take food, provide well being)
Can be ‘alternative’ detail below that
CSG outcomes
Assess options against Values & risk
Consensus?
Seek further scenarios?
TLG advise using:
Guidelines (e.g., NOF)
Existing information
Experts input
TLG, using experts for:
Predictive modelling
Non-market valuation studies

19. Example of stepping-through the process
Value: Swimmable
Attribute: Bacteria (E.coli/100ml, 95th percentile)
Attribute Levels: Excellent (<55), Satisfactory (55 – 550), Unsatisfactory (>550)
Current State: % samples in following ‘swimmable’ categories
Main-stem sites of:
Excellent
Satisfactory
Unsatisfactory
Upper Waikato
40%
60% 0%
Waipa
100%
Lower Waikato
20%
80%
Scenario Analysis: Model options for reducing faecal bacteria input to waters – wastewater treatment, denying stock access to streams, etc.

20. Scenario Analysis - predictive models, a window on the future
Computer models are a well-used and trusted analytical tool
Used in natural sciences, medicine, engineering, accounting, economics, etc.
Provide predictions of the future – can play the ‘what if..?’ game
Models collect, connect and apply expert knowledge
They need good data as input, and often use data to test validity of output
Need to choose models that are ‘fit for purpose’ – that answer the question posed
They are not perfect and need careful interpretation

21. In Summary, the Approach:
Is sequential rather than simultaneous (mostly)
Is iterative rather than once-through
Needs more technical work on defining attribute limits to meet CSG Values
Requires more scenario modelling, targeted to the needs of the CSG
Is complex, requires the ‘bringing together’ of diverse technical work across market and non-market values to provide a clear options analysis
Will require decisions to be made where uncertainty exists

22. Input to the Collaborative Stakeholder Group (CSG) to date
CSG #3 at Tokoroa – State and trends in water quality
CSG #4 at Te Kuiti – Approach to incorporating technical input into process
Answering a variety of queries posed by the CSG
Now:
Determining information needs and gaps
Preparing technical input for CSG#5

23. CSG#5 – Technical Primer on sources and mitigations
P fertiliser
P to stream P
Rock mineral P
N in urine
N as gas
Leached N
Atmospheric N
N fixation/N fertiliser N
slips & soil erosion
bank & gully
erosion
Runoff
livestock excreta
sediment
bugs

24. Determining information needs and gaps to assist CSG
Much work done
Much work already underway/nearing completion, e.g.,
Economic Joint Venture modelling
Non-market values research
Waipa sediment sources study
River algae growth response to N and P
Much work to do. Work plans being prepared for:
Defining attribute levels to meet Values
Scenario modelling – water quality, farm mitigations, economic effects
Incorporating maatauranga Maori