resources in the Greater Heretaunga and Ahuriri catchment area - - PowerPoint PPT Presentation

Making decisions for freshwater resources in the Greater Heretaunga and Ahuriri catchment area

Outline of Presentations

• Purpose for this meeting
• What the TANK project is about
• What do you value about your freshwater?
• A few water quality statistics and what they

mean for your freshwater values

• What we know about sediment, bacteria and

nutrient sources

• Good Agricultural Practice
• Being involved

Why we are here

• This meeting is to introduce TANK project and;
• Explain the process and outputs
• Provide information about key issues
• Encourage and support your involvement in this process
• TANK Group decisions need to be informed by community

involvement and support

• Managing water quality requires integrated catchment

management

What the TANK project is about

• National direction
• NPSFM;2014
• Process and requirements
• Timeframes
• Objectives, limits and methods
• Prevent over-allocation
• Quality and quantity
• Consent expiry

Greater Heretaunga and Ahuriri Land and Water Plan Change (TANK)

Catchments defined from surface water boundaries

TANK Plan Development Process

• The TANK Group is a community based

collaborative approach to developing regional plans.

• A process to;
• develop a shared understanding about

important freshwater values

• enable better understanding of the science

and the issues

• result in more enduring solutions and;
• allow collective responsibility for outcomes
• reduce areas of contest in Plan Change

process

TANK Group Membership;

wide range of people and interests represented Project Goal:

• Identify values,
• Recommend draft plan

change to provide for those values by end 2017

• Regional Planning Committee to

“have particular regard to any consensus recommendations from the TANK Group”

Freshwater Values

• National Values – compulsory
• Ecosystem Health
• health and mauri of water
• Human health – secondary contact
• Other important values include;
• Swimming
• Irrigation
• Mahinga kai
• Domestic and urban supply
• Stock water

Local Freshwater Values

• Key issue;
• Managing tributaries of the Ngaruroro

and Tutaekuri to meet water quality state for swimming;

• Other local values?
• Accounting also for impacts on estuary

and coastal values

• Nutrient and sediment loads in freshwater

Land use Climate: Rain, temperature Geology Hills / Plains Land Stream River Estuary, Ocean Oxygen Habitat

Nutrients DIN/DRP Algae Sediment

Flow Contaminants Temperature Water quality Aquatic plants

Ecosystem Health

Sediment Nutrients Pathogens Light Cultural values Human health Recreation Estuary Habitat: mussels, fish, sea grass beds, birds

Ngaruroro and Tutaekuri catchments

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Nutrients and algae

Nutrients:

• Phosphorus (DRP)
• Nitrogen (DIN)
• Light
• Temperature
• Resetting flows
• Substrate size

Algal growth depends on:

Tutaekuri catchment

Mangaone

Rissington Patoka

Mangatutu Upper Tutaekuri

Otakarara Waikonini

Lower Tutaekuri

Sherenden

Very high DRP Moderate to high DIN Very low DRP Very low DIN Very high DRP high DIN

Nutrients and algae: Tutaekuri

High DRP moderate DIN Very high DRP Low to moderate DIN

Very high

All samples above guidelines

High

Most samples above guidelines

Moderate

most samples below guidelines but many above

Low

Most samples below stringent guidelines

Very low

All samples below all guidelines

Ngaruroro catchment

Nutrients and algae: Ngaruroro

Slightly higher nutrients, more algae

Very high DRP Moderate to high DIN Very low DRP Very low DIN

Very high DRP High DIN Very high

All samples above guidelines

High

Most samples above guidelines

Moderate

most samples below guidelines but many above

Low

Most samples below stringent guidelines

Very low

All samples below all guidelines

• E. coli no problem

except for:

• Ohiwa
• (Tutaekuri-Waimate)
• (Waitio)

MCI

Macroinvertebrate Community Index

Poor Fair Good Excellent

Factors influencing MCI

• Organic pollution / oxygen
• Temperature
• Habitat (clean gravel, habitat variability)
• Toxicants (e.g. ammonia, nitrate)
• Flow

Photos: Landcare Research

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Clarity/visibility

• Recreation: Safety, aesthetics;

Determines how well you see in the water

• Ecosystem health, fishery: Visibility

determines success of fish catching prey (visual drift feeders like trout) Amount of particles

• Clogging/destroying nets of filter

feeders,

• Abrading, damaging gills.
• Fills stomach of filter feeders with

indigestible silt/clay  less energy for growth, reproduction

Water clarity and turbidity, deposited sediment

Impact on values

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Clean sediment functions:

• Spaces between gravel and cobble are (1) habitat, (2) refuge during flood events and high

temperature!

• Flow between gravel keeps temperatures cool (braided main stems)
• Exchange with groundwater
• Reaction surface for microorganisms (cleans water)

Water clarity and turbidity, deposited sediment

Impact on values

Tutaekuri at Lawrence Hut Mangatutu Tutaekuri at Brookfields Bridge

Impact on values

Increasing sediment deposited on stream bed

Clarity 2 m 10 20% cover Clarity 6 m 3% cover Clarity <1.5 m 17% cover

Sediment: Tutaekuri catchment

Clarity 1.5 m 14% cover Clarity 2 m 25% cover

Clarity 5 m

Sediment: Ngaruroro catchment

Increasing sediment deposited on stream bed From upstream to downstream

Clarity 4.7 m 15% cover Clarity 1 m 13% cover Clarity 3 m 30% / 5% cover Clarity 1m 40% cover Clarity <3.5 m 7% cover Clarity <2.5 m 35% cover

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Clarity/visibility/ light penetration

• Recreation: Determines how well you

see in the water

• Ecosystem health: Visibility

determines success of fish catching prey

• Shift from eelgrass and macroalgae to

phytoplankton and high turbidity Amount of particles in the water:

• Clogs and abrades gills of filter

feeders

• Filter feeders have to filter more 

less energy for growth, reproduction

Estuary: Water clarity and turbidity

Eelgrass Phytoplankton

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Deposited sediment:

• Change in substrate from gravel and sand (slide on left) to mud (centre slide) means

change in species (SoE monitoring)

• Smothering of eelgrass and intertidal vegetation (left slide)
• Smothering of shellfish beds and other infauna (middle slide and SOE data)
• Anoxic layer at surface a sign of increasing fine sediment – nothing can live in this (right

slide) !

Ahuriri Estuary Waitangi estuary Waitangi estuary

Deposited sediment

Impact on estuarine values

Estuaries - SOE

Mud content (% silt/clay)

20 40 60 80 100

Aonides spp. (abundance per 0.133m2)

10 20 30 40 50 60 70

20%

Summary

No issues with

• Nitrate and ammonia toxicity
• E. coli (except few tributaries)

Keep an eye on

• Nutrients (particularly P) in tributaries

 Algae, - lower Ngaruroro

• Sediment

Sediment modelling in the TANK catchments

Where from, where to and how much?

The SedNet model

• Comprised of several sub models
• Models takes into account;
• Land slope
• Land cover
• River flows
• River bank erosion
• Sediment deposition on river beds & banks

What the model can do?

SedNet modelling can;

• Identify sources of sediment.
• Calculate the area of land (hectares) that is vulnerable to sediment

generation.

• Estimate the amount of sediment coming from these areas in tonnes.
• Estimate catchment and sub catchment loads (tonnes/Year) and yields

(tonnes/km2/year).

• Predict rough particle size of sediment produced e.g. sandy, silty or clay.
• Predict the amount of reduction with increasing stock exclusion.

Each Catchment can be quantified (tonnes sediment loss per year)

Total sediment loss from the combined TANK catchments of 1.16 million tonnes per year

Tutaekuri catchment - load v Yield

Total load (t/yr) Total yield (t/km2/yr)

Tutaekuri Sub-catchments Sediment loss (tonnes) Mangaone 171,884 Tutaekuri Corridor 71,635 Upper Tutaekuri 51,569 Mangatutu 50,554 Waikonini 17,578 Otakarara 9,072 Tutaekuri Catchment Total sediment loss (Tonnes / year) 372,292

< 0 0 - 250 250 - 500 500 - 750 750 - 1000 1000 - 1250 > 1250

Average loss of 4.5 tonnes/ha/yr

t/km2/yr

Ahuriri catchment - load v Yield

Total load (t/yr) Total yield (t/km2/yr)

< 0 0 - 250 250 - 500 500 - 750 750 - 1000 1000 - 1250 > 1250

Average loss of 3.1 tonnes/ha/yr

t/km2/yr

Ngaruroro catchment - load v Yield

Total load (t/yr) Total yield (t/km2/yr)

< 0 0 - 250 250 - 500 500 - 750 750 - 1000 1000 - 1250 > 1250

Average loss of 3.5 tonnes/ha/yr

t/km2/yr

Ngaruroro catchment - load v Yield

Total load (t/yr) Total yield (t/km2/yr)

< 0 0 - 250 250 - 500 500 - 750 750 - 1000 1000 - 1250 > 1250

Average loss of 3.5 tonnes/ha/yr

t/km2/yr

Karamu sub-catchment sediment loss (t/year)

Karamu Sub-catchments Sediment loss (tonnes) Paritua-Karewarewa 27,293 Awanui 5,807 Poukawa 4,748 Havelock North Streams 3,328 Karamu-Clive Corridor 1,058 Mangateretere

• 148

Louisa

• 238

Irongate-Southland

• 521

Muddy Creek

• 1,726

Hastings Streams

• 2,398

Raupare

• 4,201

Karamu Catchment Total sediment loss (Tonnes / year) 33,001

Average loss of 0.6 tonnes/ha/yr

Sediment model resolution Each colour (river reach) can be quantified

Sediment loss (t/yr) at Higher resolution. Showing total sediment loss at a “river reach” scale.

Tonnes of sediment lost per year

Riparian Condition Assessment Results: Stock access

Karamu and lower Ahuriri catchments - Low level of stock access Very low level (or NIL) of stock access High level of stock access

Reduction of sediment with increasing stock exclusion

Current fencing tonnes/Year

< 10 > 10 - 25 > 25 - 50 > 50 - 100 > 100 - 250 > 250 - 500 > 500

Current estimated sediment loss from TANK through river bank erosion;

222,425 tonnes per year

Linking sediment and phosphorus

• Binds strongly to soil particles/sediment
• Phosphorus is usually found as phosphate under normal

environmental conditions

• Can be released under certain environmental conditions e.g. low
• xygen environments
• Causes algal blooms and other plant growth in rivers.

Modelled Phosphorus loss across the TANK Catchments

Predicted sediment particle size across the TANK Catchments Finer particles can add and transport more nutrients. Possibly target the finer sediments for most effect?

What do we mean by industry good practice?

What we know about good practice to avoid causing water quality impacts and prevent soil and nutrient loss from farmland

What it means for you

• What could the regional plan mean for

you?

• How we manage in the Tukituki (PC6)

Tukituki Plan Change

• What does it mean for land owners there
• Stock exclusion rules
• Farm Environmental Management Plans
• Colin Tyler
• Senior Land Management Advisor

Who is affected in the Tukituki?

• All properties over

4 ha in size

• Not just dairy or

irrigated

• Biggest sector by

land area and numbers is sheep and beef

• Some

exceptions for “low intensity farming systems” but only <10ha

Stock Exclusion

Stock in waterways can be a major source of

• P, N, Sediment and Faecal

Bacteria Big benefits compared to some

• ther mitigations

Good Practice already in place for many farms through voluntary actions But rules now also a part of business

• Tukituki
• Sustainable Dairying:Water

Accord How will good practice and regulation look in future? What is best?

Tukituki Rule re Stock Exclusion

• Does not apply to sheep
• Required by 31 May 2020
• Where not “reasonably practical” need to outline what is being done in place of stock

exclusion

• Do so in Farm Environmental Management Plan (FEMP)

FEMPs

What is affecting water quality---------what will be done about it However is a complex document (Schedule XXII

• f Tukituki Plan Change)

and has to include

• Comprehensive mapping
• A Phosphorous Management Plan
• Objectives

for Nutrient, Irrigation, Soils, Wetlands, Riparian, Collected Animal Effluent and Lifestock Management ….not just stock exclusion

• A Nutrient Budget

Needs sign off and input from suitably qualified person $$$ Due by 30 June 2018

National Focus on both Stock Exclusion and FEMPs

Being involved – Being informed

• How can you assist the TANK Group in its

decision making?

• Stakeholder groups;
• Federated Farmers
• Beef and Lamb NZ,
• Fonterra/ Dairy NZ
• HDC Rural Community Board
• Community/Catchment groups?
• What could this look like?
• Other sources of information;
• HBRC website – TANK project
• Think TANK updates
• Public meetings

Hawke’s Bay Biodiversity Strategy Call ll out t to th the farming communit ity

We want to hold a workshop to cover:

• What is the HB Biodiversity Strategy and what is it trying to

achieve

• What is the current state of the biodiversity in HB
• What role could/should the farming community play in

practice

• How can the farming community influence what gets done

where and when

• Sharing your experience – if you have real life examples of

biodiversity projects making a difference on the ground, we want to hear about it!

Our indigenous biodiversity is in decline, but through working together, we can make a difference.

If you are interested, please contact Nick Dawson, Federated Farmers nick.nicky@xtra.co.nz pH 06-839-8996