Water management workshop
Workshop outline - Groundwater investigations (Stephen) - New water meter regulations (Jude) - GW compliance strategy (Jock) - Installation and verification (Stephen) 2
investigations Groundwater
Groundwater investigations – Why? • Initiated in 2005 in response to increasing demand and declining groundwater levels 4
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 5
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 6
Groundwater investigations Phase 3 & 4 - Groundwater assessment Models used to simulate different water abstraction and climate scenarios to predict impacts on the groundwater Phase 3 – Wairarapa resource AND impacts on surface Phase 4 – Kapiti / Wellington water bodies 7
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 8
Groundwater investigations Proposed management zones Middle Valley 9
Groundwater investigations Proposed abstraction categories Spatial component Category A Direct hydraulic connectivity Category B High hydraulic connectivity Category C Moderate to low hydraulic connectivity 10
Groundwater investigations Proposed abstraction categories – Middle Valley Category A Direct hydraulic connectivity Category B High hydraulic connectivity Category C Moderate to low hydraulic connectivity 11
Groundwater investigations Proposed abstraction categories Depth component Mangatarere water Parkvalewater Middle Ruamahanga wate management zone management zone management zone Parkvale Stream / Mangatarere Ruamahanga B B’ Booths Creek Stream River Category B Category A 10m Category B Category A 20m 30m Category C 12
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 13
Groundwater investigations SPASMO irrigation allocation tool Climate data Irrigation type Soil type Annual irrigation requirements 14
New water metering regulations
New water metering regulations • Applies to all takes greater than 5 litres/sec • Standards for water measuring devices specified Daily records (in m 3 ) required unless approval • for weekly records provided by Regional Council 16
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 17
New water meter regulations Timeframes • 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 18
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 19
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 20
GW compliance monitoring strategy for water takes
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 22
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 23
Installation and verification
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 25
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 26
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 of 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 27
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 28
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 29
Installation Requirements on completion • Submission of installation and commissioning report – see Irrigation NZ Guidelines for a template (Appendix H) 30
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 31
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) 32
Installation and verification Examples • Good straight length of pipe • Likely to meet installation best practice • Likely to be suitable for in-situ verification 33
Installation and verification Examples • Fails requirements for installation and verification • Poor straight length • Significant headwork alterations required 34
Installation and verification Examples • Gate valve on water meter flange • Likely inadequate straight pipe before meter • Some work required but not significant 35
Installation and verification Examples • Increase straight pipe prior to meter possibly required • Inadequate straight pipe after meter • Shift gate valve 36
Installation and verification Examples • Generally good straight length • Increased straight length may be required due to gate valve or shift gate valve 37
Installation and verification Examples • No straight length • Significant alterations required 38
Installation and verification Example – GW test site @ Hammonds 2008 – faulty mechanical meter, pipe length OK but gate valve on intake side of meter 39
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 40
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 41
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