Managed Aquifer Recharge Programme Information Hinds/Hekeao Catchment (Canterbury) Managed Aquifer Recharge Programme Information Bob Bower, Principal Hydrologist RDR Klondyke Storage Consent Hearing 15th February 2018 1:40 pm

What is Managed Aquifer Recharge? A set of physical tools designed to intentionally recharge water into an aquifer for economic, environmental, social, and culture benefits. https://www.un-igrac.org/areas-expertise/managed-aquifer-recharge-mar

2nd April 2018 ~400,000,000 m3/year 2017 of recharge Restoring groundwater levels for springs and baseflows to river Increase reliability of groundwater bores

National MAR Pilot Projects Gisborne MAR Pilot Hinds/Hekeao Groundwater Replenishment Scheme Southland MAR Pilot

Managed Aquifer Recharge Tools of Integrated Water Management

Groundwater Replenishment Scheme The Bigger Picture Catchment-scale, conjunctive, sustainable groundwater management. Tools of MAR Groundwater Replenishment Scheme

Hinds Catchment Between Rangitata and Ashburton Rivers HINDS RIVER VALETTA MAYFIELD HINDS

Hinds/Hekeao Catchment Approach Economics March 2014

(Scott, 2013)

BALANCING GROUNDWATER: QUANTITY & QUALITY ADDITIONAL YIELD ADDITIONAL MAR ADDITIONAL ALLOCATION SUSTAINABLE YIELD MAR OVER ALLOCATION ABSTRACTION Nutrient Leaching Increases “LOSSES’ IRRIGATION & OPEN RACES NATURAL YIELD RAINFALL GROUNDWATER OUTFLOW EVAPORATION RIVER & STREAMS BASEFLOWS TO SPRINGS AND RIVERS RECHARGE DISCHARGE NATURAL GROUNDWATER STORAGE DECLINING STORAGE & SPRING FLOWS MANAGED STORAGE INCREASING STORAGE & BASEFLOWS Golder 2017, Hinds Managed Aquifer Recharge Pilot Trial: Phase 1 Report

Depth to Groundwater (m) Changing dynamic groundwater storage DEPTH OF BORE LEVELS (K37/0300 – GWE-4) -5 -10 -15 -20 -25 WETTER SEASONS Depth to Groundwater (m) DROUGHT SEASONS IRRIGATION & STOCKWATER EFFICIENCIES + GROUNDWATER USAGE DROUGHT SEASONS -22.8m 1973 1975 1977 1979 1981 1983 1985 1987 1989 1991 1993 1995 1997 1999 2001 2003 2005 2007 2009 2012 2014 2016 Time

36 Spring-fed streams and Hinds River Over 230 km of streams and groundwater dependent ecosystem habitat Cultural Values including Mahinga Kai sites (HDWP) Threatened Aquatic and Endangered Species Until recently strongholds for native and non-native species

Average Annual Nitrate-Nitrogen Concentration (mg/L) Hinds Catchment – Increasing of Nitrate Levels 12 10 8 6 4 2 Drinking water max accepted value (MAV) SHALLOW GROUNDWATER SURFACE WATER DRAINS Guideline – 80% protection of aquatic biodiversity Average Annual Nitrate-Nitrogen Concentration (mg/L) Half MAV average concentration target Guideline – 90% protection of aquatic biodiversity DEEP GROUNDWATER 1990 1995 2000 2005 2010 2015

MAR Programme: Targeting Drinking Water Benefits Tinwald High Nitrate Area MAR Programme: Targeting Drinking Water Benefits Key Drinking Water Issues 80% of Ashburton Residents take water from rural bores CDHB reports some of highest rates of enteric diseases (Ashburton District) Drinking water protection a national concern (E.g. Havelock) Tynwald Plume targeted my MAR Pilot Trial 6 community supply systems including towns of Hinds, Mayfield and Ashburton

Hinds Mitigations QUANTITY QUALITY Cap new groundwater allocations Review existing permits for actual usage (metering rule) Community solutions Allow surface users to transfer to groundwater Initiate MAR pilot for proof of concept testing QUALITY Reduce nitrogen losses at farm level 36% by 2035 Set a groundwater quality target for catchment reached of 6.9 mg/L by 2035 Initiate MAR pilot for proof of concept testing

MAR Pilot Testing Site MAR Site final location Higher nitrate plume MAR testing location background HINDS RIVER VALETTA MAR Site final location MAYFIELD HINDS Higher nitrate plume Most impacted baseflows Source Map – Golder, 2017

Hind/Hekeoa Catchment Infiltration Basin with Forebay, and Monitoring MAR SITE BORE SITE ACCESS GATE FOREBAY MAIN INFILTRATION BASIN MAIN BASIN LEVEL TIMARU TRACK FRASERS ROAD OVERFLOW BYPASS GATE MAR SITE BOUNDARY

YEAR 1 – WATER QUANTITY AND QUALITY COMPOSITE RESULTS (GWD-4 BORE) 5 10 15 20 25 30 10 8 6 4 2 DEPTH TO WATER Groundwater level as measured from the surface (m) Nitrate N Concentration (mgN/L) FIELD MONITORING LAB RESULTS NO3-N LINCOLN AGRITECH SENSOR NO3-N 27/4/16 17/5/16 6/6/16 16/7/16 5/8/16 4/10/16 26/6/16 25/8/16 14/9/16

Year 1 - Results Quantity Quality Site operations 279 Days of operations – 10 June 2016 to 9 June 2017 Year 1 - Results Increases in groundwater levels approximately 7 km from the Pilot Trial site. Site operations 2.4 Million m3 of new recharge 8% of Valetta GAZ overallocation Quality MAR command area: groundwater nitrate-N values from 14 g/m3 to < 4 g/m3 Improvements in quality for domestic supply bore tested, but much more needed. Passive soil aquifer treatment (S.A.T.)

Developing a Catchment-Scale Groundwater Replenishment Scheme Current Programme of Works (2017 to 2019)

Prepared for the MAR GG Business Case Workshop Community Scaled Solutions for Catchment Scale Issues Hinds GRS Goals Increase and actively management groundwater storage (levels) Community scale solutions Improve water quality in aquifer (springs) Improve flows and quality in spring-fed streams and rivers for ecological and cultural values Improve and protect drinking water supplies What key aspects of the GRS Mission and Goals need to be confirmed for the Business Case? WGA NZ

Prepared for the MAR GG Business Case Workshop Work Programme Hinds GRS Programme Business Case and Master Plan Community scale solutions Setting Goals and Programme Milestones Continuing to develop the MAR Tools through science-based testing and designs Representative and Accountable Governance Community input and guidance Set annual recharge goal 125,000,000 m3 (10 year Goal) What key aspects of the GRS Mission and Goals need to be confirmed for the Business Case? WGA NZ

2017-18 New MAR Testing Sites

Testing Site Concept Design Full Utilisation of ADC Unused Stockwater (500 l/s) MAR Pilot Site currently 113 l/s with enhancement in consenting process (March) 16 sites have been consented up to 50 L/s per site. 12 have been constructed, 3 are currently operating. Near River Recharge in consenting (up to 200 l/s). Greater than 500 l/s MAR capacity tested by May 2018. Testing Site Concept Design

COMMUNITY PARTNERSHIPS Focusing on maintaining strong and diverse partnerships to ensure programme goals are representative of community

Christchurch 4 Ash Street, Christchurch Central 8011 Telephone: 029 201 2996 WALLBRIDGE GILBERT AZTEC www.wganz.co.nz bbower@wganz.co.nz Questions?