Waihopai/Omaka Rivers Programme
Total Page:16
File Type:pdf, Size:1020Kb
Water Allocation and Use Community Meetings Waihopai/Omaka Rivers Programme • Setting the scene • Efficient allocation • Setting limits • Enhanced transfer • Encouraging storage • Effects of afforestation on water yield • Frost fighting • Next steps Setting the Scene •Pere Hawes (Manager Environmental Policy) Current management • Operative management framework for water allocation and use • Demand anticipated from aquifers and larger river catchments • “Sustainable Flow Regimes” established – Minimum flows for rivers – Allocation classes (each with a limit) Current management • Approximately 1300 water permits • Ease of access to water enabled rapid expansion of viticulture – Two appeals heard by the Environment Court • Productive value is approximately $1.1billion – 77% of the contribution is to primary production Driver 1: Review process • Statutory requirement – Review of the effectiveness and efficiency of “sustainable flow regime” – Emerging allocation issues as limits approached Driver 2: NPSFM 2014 (and 2011) • Requirement to give effect to the NPSFM 2014 – Set environmental flows/levels and allocation limits – Efficient allocation – Criteria for transfer – Encourage efficient use – Avoid future over allocation – Phase out over allocation Water Forum February 2012 • Initiated review • All water users and others with an interest in water invited • Current status of resources • Confirm issues to be addressed through review • Identified strategic issues Strategic issues • Full allocation of water resources* • Allocative efficiency* • Over allocation of water resources • Setting of limits* • Encouraging water storage* Water Allocation Working Group (WAWG) • Representatives of water users – Different water uses – Different geographical areas • Make use of experience in water management • Advise Council on management options • Has met monthly since July 2012 WAWG Membership • Clr Geoff Evans •Dr R. • Francis Maher Balasubramaniam • John Hickman (Bala) • Guy Lissaman • Steve Wilkes • Dr John Small • Neil Deans • Mike Insley • Dr John Bright • Dominic Pecchenino • John Patterson Strategic issues • Equitable access to water (WAWG)* • Certainty and reliability (WAWG)* • The effects of groundwater abstraction on surface water (WAWG)* • Effects of afforestation on water yield (WAWG)* Regional Planning and Development Committee • WAWG reported recommendations to Committee • Committee has adopted recommendations for the purpose of consultation • Test recommendations – Seeking feedback from water users and others with an interest in freshwater Purpose of Meeting • Provide briefing on management proposals for the Waihopai and Omaka catchments • Provide opportunity for feedback on these proposals Efficient Allocation • John Bright (Aqualinc Research Ltd) The issue • Difference between paper allocation and actual use – Use of generic allocation guidelines The issue Consented Rate of Take Water volume allocated but not used (locked up) Water volume actually used The issue Consented Rate of Take Water volume allocated but not used (locked up) Water volume actually used Water freed up for allocation to someone else The issue: a lot of water allocated but not used, even in dry years. Consented Rate of Take Water volume allocated but not used (locked up) Water volume actually used Water freed up for allocation to someone else Proposal • Accurately define reasonable use requirements for irrigation • Reasonable use volumes should reflect demand under efficient operations. • Demand determined by: – Crop type(s) – Soils – Climate – Irrigation method Water Permits – to use water Reasonable use volumes are specific to the property concerned and reflect climate, soils, crops, and irrigation systems on that property. Reasonable use volumes are typically set at a level that fully meets irrigation requirements on the property 9 years out of 10, and meets a large part of requirements in the very driest years. Annual irrigation water use 9 year in 10 reasonable use volume Reasonable Use Volumes by Month 9 year in 10 reasonable use volume by month (cubic metres per hectare per day) Reasonable Use Volumes by Month 9 year in 10 reasonable use volume by month (cubic metres per hectare per day) Info on Reasonable Use Volumes • Will provide on-line access to reasonable use volumes determined using IrriCalc – a tool for modelling irrigation water use • Provides default volumes • Flexibility to provide property specific information to justify alternative allocation Summary • Application of reasonable use test achieves efficient allocation Setting Limits – Waihopai River •Val Wadsworth (Surface Water Hydrologist) •Peter Hamill (Environmental Scientist) National Policy Statement Freshwater Management 2014 • Required to set environmental flows and/or levels – Allocation limit – Minimum flow Triple class system C shut-off, B restrictions begin C B shut-off, A restrictions begin Flow B A A shut-off SFR Flow decreasing with time Waihopai River - Current management • SFR Flow – Waihopai River above Gibsons Creek Diversion: 1.35 m3/s Waihopai River - Current management • Class A – 0.25 m3/s • Class B – 1.13 m3/s • Class C – 67% of any flow above 3.6 m3/s Waihopai River - Current management • Class A restriction – No take below 1.5 m3/s at Craiglochart • Class B restriction – No take below 1.9 m3/s at Craiglochart • Class C restriction – No take below 3.6 m3/s at Craiglochart • Rationing 9 8 Natural Flow Gibsons Ck 0.35 m3/s, Losses 0.15 m3/s 7 Class A allocation 0.4 0m3/s Flow after abstraction Class B allocation 1.13 m3/s 6 5 Class C allocation 2.80m3/s Flow m3/s) 4 3 2 1 Environmental flow 1.00 m3/s 0 0 1020304050607080 Time (days) Current status • Class A and Class B fully allocated • 283,000 m3/day of Class C allocated • Rationing has not been implemented • Takes of groundwater managed as surface water • Takes from tributaries have Waihopai minimum flow apply Waihopai River - Review • Minimum flows reviewed • No evidence of adverse effects at low flows • Allocation classes reviewed • Any increase/alteration in allocation adversely effects reliability of existing users • No C class limit • Concerns that exercise of large C class takes effects reliability of other C class takes • Non-compliance with NPSFW Waihopai River - Review • Rationing still required to meet SFR at Gibsons Creek diversion • Equity of treatment when compared to other Wairau catchment takes • All other Wairau catchment takes subject to Wairau River minimum flows • Effect of takes of groundwater in lower part of the catchment on river flows? 10 Natural Flow 8 Gibsons Ck Diversion 0.35 m3/s, losses 0.15 m3/s Class A allocation 0.4 0m3/s Flow after abstraction Class B allocation 1.13 m3/s 6 Class C allocation 2.80m3/s 4 Flow m3/s) 2 Environmental flow 1.00 m3/s 0 0 1020304050607080 -2 Time (days) Waihopai River - Proposal • Current triple class system retained – Allocation limits – Minimum flows • Class C capped at 2.8 m3/s • Rationing retained – Flexibility provided to users to develop own regime • Use daily average flow to administer minimum flow – Timing of daily average? Waihopai River - Proposal • Wairau River minimum flow to apply –8 m3/s at Tuamarina Waihopai River - Proposal Waihopai River - Proposal • Takes of riparian groundwater continue to be managed as Lower surface water Waihopai • Lower Waihopai groundwater takes managed separately Omaka Waihopai River - Proposal • Takes from tributaries will still attract Waihopai minimum flow Waihopai Setting Limits – Omaka River •Peter Davidson (Groundwater Scientist) •Peter Hamill (Senior Water Quality Scientist) Omaka - Current management • No Sustainable Flow Regime included in WARMP • Allocation limit for “Omaka River Valley Aquifer” • Class A of 14,860m3/day • No minimum flow set Omaka - Current management • Developed informal allocation regime over time • Successive water permits subject to more stringent environmental conditions • Match availability with certainty of supply • Seek to maintain groundwater levels at Woodbourne • Have come to be referred to as Class A, Class B and Class C Omaka – Current management • Aquifer driven by Omaka River flows • Two low yielding aquifer layers • All river flow lost to aquifer in typical summer • Underground flows continue to Woodbourne area Omaka River/Aquifer Hydrology Connection with Woodbourne Omaka River/Aquifer Hydrology – Omaka River flow range: 67 – 253,000 l/s – Shallow aquifer level range: 1.8 m. – Deeper aquifer level range: 12 m Omaka River/Aquifer Hydrology Omaka River/Aquifer Hydrology Omaka River - Current status • Fully allocated resource under informal regime • Concerns expressed in Woodbourne area regarding status of aquifer levels • Reduced reliability of existing takes Omaka River - Review • Review of informal allocation regime – Naturally ephemeral river in lower reaches – Not required to set minimum flow – Important habitat in permanently flowing reaches – Flow connection important at critical times of the year • Connection with Woodbourne investigated – Surface and subsurface flows contribute to aquifer levels at Woodbourne Omaka River - Proposal • Manage Omaka River and Woodbourne as same management unit Omaka River - Proposal • Formalise triple class system C shut-off, B restrictions begin C B shut-off, A restrictions begin Flow B A A shut-off SFR Flow decreasing with time Omaka River - Proposal • Seek to maintain aquifer levels at Woodbourne – Managing flows at which Class C, B and A can be abstracted • Seeking to retain recharge of aquifer at Woodbourne at higher flows