Making decisions for freshwater resources in the Greater Heretaunga and Ahuriri catchment area March 2017
Welcome and Introductions
Outline of Presentations • Purpose for this meeting • Update on the TANK project • What the TANK Group is considering • A few sediment facts and what they mean for your freshwater values • Breakout sessions for discussion and feedback • Farmer involvement – what is happening already • What else needs to happen? • Support and advice • Timelines
What the TANK project is about; • The TANK Group is a community based collaborative approach to developing a regional plan for the Ngaruroro Tutaekuri, Ahuriri and Karamu Catchments • The TANK project is a process to; • develop a shared understanding about important freshwater values and how to provide for them • enable better understanding of the science and the issues • result in more enduring solutions • allow collective responsibility for outcomes • reduce areas of contest in the Plan Change process
Greater Heretaunga and Ahuriri Land and Water Plan Change (TANK) Catchments defined from surface water boundaries
TANK Update
A values-based approach to management • Key Values; • Ecosystem health and mauri of water • Social and recreational values like swimming • Other important values include; • Irrigation • Mahinga kai • Domestic and urban supply • Stock water • Some of the ecosystem and social values are not being met. • A strong desire by the TANK Group to improve the way we manage water resources
Sediment - Tutaekuri Clarity <1.5 m 17% cover Clarity 6 m Clarity 2 m 3% cover 10 20% cover Clarity 1.5 m 14% cover Clarity 2 m Increasing sediment 25% cover deposited on stream bed
Nutrients and algae: Tutaekuri All samples above Very high guidelines Most samples above High guidelines most samples below Moderate guidelines but many Very high DRP above Very high DRP high DIN Most samples below Low Moderate to stringent guidelines high DIN All samples below all Very low guidelines Very low DRP Very low DIN High DRP moderate DIN Very high DRP Low to moderate DIN
Summary for Tutaekuri catchment No issues with • E. coli • Nitrate and ammonia toxicity Keep an eye on • Nutrients, particularly P Algae, - lower Tutaekuri • Sediment
Why is Sediment Management and Erosion Control is Important • On farm benefits • Production • Stock health • Amenity • Farm infrastructure (fences, farm dams, tracks, buildings) • Etc • Off-site benefits • Biodiversity • Amenity • Protection of infrastructure (roads/services) • Water quality and ecosystem health
Why is there a focus on sediment? • It means we can take advantage of contaminant pathways; • Phosphorous often attached to sediment • Measures to reduce stream bank erosion can also be effective at reducing bacteria levels • Better riparian management can also reduce losses of nitrogen • Sediment is one of the key stressors for ecosystem health; • freshwater as well as estuary and the coast
Reducing Sediment Loss in the TANK catchments Where from, how and how much?
Models and maps help predict and target the effect of different management approaches at a catchment scale • Where most of the sediment is likely to be coming from • What type of erosion is resulting in sediment loss • Loss by location • Worst water quality
Estimate of human influence on sediment loss Current Hillslope erosion compared to forested catchment Pre-human Current Hillslope Hillslope Pre-human as % Catchment Sediment Load Sediment Load of current load (t/yr) (t/yr) TANK (Tutaekuri) 90,394 333,651 27 TANK (Ahuriri) 8,009 54,723 15 TANK (Ngaruroro) 197,780 554,382 36 TANK (Karamu) 7,340 46,538 16 TANK hill country 303,522 989,294 31 total 15
Breakdown of erosion types in TANK Bank erosion 21% Landslide 50% Surficial 22% Landslide Earthflow Gully Gully Earthflow 6% 1% Surficial Bank erosion
Sediment yield map of TANK area High concentration of erodible land (Tutaekuri and eastern Ahuriri) t/km 2 /yr < 0 0 - 250 250 - 500 500 - 750 750 - 1000 1000 - 1250 > 1250
Top 100 farms where if sediment plans were applied a 23% reduction in sediment would be expected.
Soil conservation and erosion control measures include; • Retirement of steep erodible land • Planting trees – forestry or space planting • Debris dams • Sediment ponds/wetland construction • Stock exclusion • Riparian planting • Good pasture management • Etc etc • The effectiveness of each of these methods will vary according to site specific characteristics + opportunities
From Catchment to Property Scale • Modelling done at a catchment scale – but decision making is done at a property scale • Farm Plans can be a useful, practical tool to help; • identify and address environmental risks and • programme solutions • monitor progress so that you can farm in a way that is; • environmentally sustainable, • socially acceptable, and • economically viable.
Assessing the costs…
Some things to consider.…. • Management options have been suggested – 1. a farmer led commitment plus • bottom lines (rules) for some activities • rules for some activities like cultivation, winter grazing and protecting water from stock?? 3. regulatory approach to farming imposed through plan rules and resource consents • Rules about farm plans/farming • National regulations for stock exclusion* • Biodiversity strategy • Govt Emissions Trading Scheme (forestry) and Afforestation grants
• The TANK Group want to work with farmers to; • Agree on water quality and ecosystem values and objectives • Investigate the impact of a sediment reduction target of up to 30% (of the total) and • Show how this target might be met
• BREAKOUT DISCUSSION – • Record and Report Back; • What are the steps we can take to meet the sediment management target? • What else is needed for success? • Help and resources you need to achieve reduced sediment loss from your farm • Timeframes • Monitoring implementation
Some ideas…… Peter Kay - TANK Group pastoral farmer representative Mark Harris - Beef and Lamb NZ
Being involved – Being informed • Next Steps; • Farmer reference group • Meeting 9 th May • Develop and discuss options • Feedback to farming community • Refine options • Provide suggestions to TANK Group by August 2017 • TANK group to prepare recommended draft plan change by end of November 2017
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