Water management workshop Workshop outline - Groundwater - - PDF document

Water management workshop

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Workshop outline

• Groundwater investigations (Stephen)
• New water meter regulations (Jude)
• GW compliance strategy (Jock)
• Installation and verification (Stephen)

Groundwater investigations

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Groundwater investigations

– Why?

• Initiated in 2005 in response to increasing demand

and declining groundwater levels

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Groundwater investigations

Phase 1 - Review of Wairarapa hydrogeology

Main Finding: Surface waters and groundwaters in the Wairarapa Valley are essentially one resource and should be managed as such

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Groundwater investigations

Phase 2 - Detailed groundwater modelling

3-dimensional numerical computer models built to simulate the hydrogeological environments in the Upper, Middle and Lower valleys

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Groundwater investigations

Phase 3 & 4 - Groundwater assessment

Models used to simulate different water abstraction and climate scenarios to predict impacts on the groundwater resource AND impacts on surface water bodies Phase 3 – Wairarapa Phase 4 – Kapiti / Wellington

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Groundwater investigations

Summary of outcomes

• A proposed new approach to managing

groundwater abstractions is recommended

– Integrated or “conjunctive” management surface water/groundwater management

• Proposed new groundwater management zones

and abstraction categories

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Groundwater investigations

Proposed management zones

Middle Valley

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Proposed abstraction categories

Spatial component

Category A Direct hydraulic connectivity Category B High hydraulic connectivity Category C Moderate to low hydraulic connectivity

Groundwater investigations

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Groundwater investigations

Proposed abstraction categories – Middle Valley

Category A Direct hydraulic connectivity Category B High hydraulic connectivity Category C Moderate to low hydraulic connectivity

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Groundwater investigations

Proposed abstraction categories

10m 20m 30m

Mangatarere Stream Parkvale Stream / Booths Creek Ruamahanga River

Category A Category A Category B Category B Category C

Mangatarere water management zone Parkvalewater management zone Middle Ruamahanga wate management zone

B B’

Depth component

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Groundwater investigations

SPASMO irrigation allocation tool

• A new efficient irrigation allocation tool (SPASMO)

has been developed that looks at taking into consideration site specific soil types and climate data

• Developed by Plant & Food Research in Palmerston

North and has been used in other Regional Councils in NZ

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Groundwater investigations

SPASMO irrigation allocation tool

Climate data Irrigation type Soil type Annual irrigation requirements

New water metering regulations

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New water metering regulations

• Applies to all takes greater than 5 litres/sec
• Standards for water measuring devices

specified

• Daily records (in m3) required unless approval

for weekly records provided by Regional Council

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New water metering regulations

The water meter must be:

• Installed as close as practicable to the location from

which water is taken

• Sealed and as tamper-proof as practicable
• Verified after the first year and every 5 years after

that

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• For any new and replacement consents processed after

10 November 2010, Regulations apply immediately

• For existing consents, transitional period for compliance

with Regulations depending on size of take:

– Takes greater than 20 litres/sec – comply by 2012 – Takes between 10-20 litres/sec – comply by 2014 – Takes between 5-10 litres/sec – comply by 2016

New water meter regulations

Timeframes

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New water meter regulations

How do Regulations affect GW?

• 25% of water takes in the region are less than 5 litres/sec
• Approx. 400 consents in region already require water

measuring devices

• Approx. an additional 100 consents in region will require

new water measuring devices over the next 6 years

• Many existing water measuring devices will require some

upgrading to meet Regulations

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New water meter regulations

Current consent conditions

• All conditions in consents

issued at present meet minimum requirements in new Regulations

• Installation and verification

required by accredited provider unless special circumstances apply

GW compliance monitoring strategy for water takes

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GW compliance strategy

Takes less than 5 litres/sec

• Only catchments and aquifers

that are considered to have high demand / stress will be required to be metered

• Same standards of metering

and recording as for takes covered by the Regulations will apply

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GW compliance strategy

Recording and reporting standards

Three minimum standards apply for all metered takes 1. Weekly meter reading with annual reporting 2. Daily meter reading via datalogger with annual reporting 3. Automatic meter reading via telemetry with instantaneous reporting to GW

Installation and verification

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Installation and verification

Irrigation NZ accreditation programme

• ‘Guidelines for the Measurement

and Reporting of Water Takes’ – Irrigation NZ website

• `National Consistency Guidelines

for Resource Management (Measuring and Reporting of Water Takes) Regulations 2010’ – copy in your folder

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Installation

Water meter selection and location

• Preference for mag-flow meters over mechanical

meters, but not compulsory

• Meter accuracy +/- 5% with pulse output
• Meter / headworks to be located within 20 metres of

bore or surface water take

• Exemption when located in known floodplain –

recommendation to check with GW first in such circumstances

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Installation

Headworks

• Flow disturbance can have significant effect on

measurement accuracy

• Minimum straight pipe length - industry best practice

(from Irrigation NZ guidelines) 10X PD on intake side

• f meter and 5X PD on discharge side of meter – see

Appendix G of Irrigation NZ Guidelines

• However need to consider future verification

requirements either in situ or in laboratory

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Installation

Tamper proof as practicable

• Check National Consistency Guidelines
• All flanges/joints that need to be sealed shall have one

bolt on each flange drilled and tamper sealed

• All flanges between fixed infrastructure and meter shall

be tamper sealed

• Mechanical meters shall be tamper sealed on flanges

either side of the meter

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Installation

Tamper proof as practicable

• Meter devices requiring power shall not be able to be

isolated

• Any breakages of tamper seals only to be completed

by approved installer – notify GW when done

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Installation

Requirements on completion

• Submission of installation and commissioning report –

see Irrigation NZ Guidelines for a template (Appendix H)

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Verification

Testing

• Required every 5 years
• On site verification recommended in Irrigation NZ

guidelines

• Clamp on meter verification will require more

minimum straight pipe (particularly pipe diameter before meter – most likely at least 15X pipe diameter according to Irrigation NZ Guidelines)

• Minimum 3 tests of approx. 10 mins each

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Verification

Assessing compliance and reporting

• Uncertainty of +/- 3% applied as standard for in-situ

verification

• Submission of verification report – see Irrigation NZ

website for template (Appendix L)

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Installation and verification

Examples

• Good straight

length of pipe

• Likely to meet

installation best practice

• Likely to be

suitable for in-situ verification

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Installation and verification

Examples

• Fails requirements

for installation and verification

• Poor straight length
• Significant

headwork alterations required

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Installation and verification

Examples

• Gate valve on

water meter flange

• Likely inadequate

straight pipe before meter

• Some work

required but not significant

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Installation and verification

Examples

• Increase straight

pipe prior to meter possibly required

• Inadequate

straight pipe after meter

• Shift gate valve

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Installation and verification

Examples

• Generally good

straight length

• Increased

straight length may be required due to gate valve

• r shift gate valve

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Installation and verification

Examples

• No straight length
• Significant

alterations required

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Installation and verification

Example – GW test site @ Hammonds

2008 – faulty mechanical meter, pipe length OK but gate valve on intake side of meter

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Installation and verification

Example – GW test site @ Hammonds

2010 – new ultrasonic and mechanical meters installed, however mechanical too close to elbow, gate valve on intake side of meters

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Installation and verification

Example – GW test site @ Hammonds

2011 – U bend with sufficient straight pipe installed with ultrasonic and mechanical meter, gate valve now on discharge side of meter, 15 straight pipe for verification

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Installation and verification

Easy management of meters

• GW will be ordering water meter tags for installation on

water meter or headworks

• Considering separate tag to identify current verification

and when next verification is due – thoughts?

• Do industry want GW templates for installation and

verification reports?