HINDS DRAINS WORKING PARTY MINUTES 30 OCTOBER 2014
A meeting of the Hinds Drains Working Party was held at the MRB Boardroom on
Thursday 30 October 2014 at 9:00am
PRESENT:
Peter Lowe (Chair) (Community)
Deane Taylor (Deputy Chair) (Community)
Stuart Wilson (Ashburton Zone Committee)
Bill Kingston (Community)
Ian Mackenzie (Community)
Craig Fleming (Community)
Murray Harbutt (Community)
Mark Webb (Fish and Game)
John Waugh (Forest and Bird)
Nicholas Dunn (Department of Conservation)
Gordon Guthrie (Ashburton Zone Committee)
Phil Everest (Community)
Philippa Beckman (Minutes Secretary: Environment
Canterbury)
Bob Bower (Technical Support: Environment Canterbury)
Dan Harrison (Engineering: Environment Canterbury
Brett Painter (CWMS Infrastructure: Environment Canterbury)
GUESTS:
Reuben Edkins
Hamish Tait
APOLOGIES:
Karl Russell (Arowhenua)
Sheryl Stivens (Ashburton Zone Committee)
Barry Smith (Community)
Lesley Woudberg (Facilitator: Environment Canterbury)
1.
MINUTES OF 09 OCTOBER AND 20 OCTOBER MEETINGS
Minutes of the 09 October and 20 october meetings were approved
2.
MATTERS ARISING FROM THE MINUTES
The weir on Taylors drain is to be removed, following discussions between the family
concerned and Peter Lowe.
3.
UPDATES SINCE LAST MEETING
3.1 Mark Webb reported on the Lake Hood outlet making the following points:
 0.5m may be possible. It is a very large wetland area; 200-300m long. There is a
need to find a discharge point.
 There may be fish spawning between 200-300m
 Gravel – spawning gravel is required and may need annual maintenance
 May need to seed with trout: Maybe from the Ashburton River so they can find
home
If water is insufficient, note that the Ashburton District Council has a valid water
right for that area so diversion should be possible.
Actions:
o Phil Everest and Mark Webb will prepare a proposal regarding the Lake
Hood outflow.
o Mark Webb, Ian Mackenzie and Peter Lowe will identify one drain for
enhancement and prepare a proposal.
o Peter Lowe and Stuart Wilson will identify mahinga kai areas and prepare
a proposal to include water and signage requirements
3.2 Ashburton Zone committee report:
 Peter Lowe spoke to the Zone Committee reporting on this group’s actions to
date. These were well received.
 Funding: Funding is needed for several activities such as stockwater change,
water in Hinds, riffles, signage for mahinga kai. This committee will request the
Zone Committee for funds:
Action: Peter Lowe to approach Zone Committee for funds.
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HINDS DRAINS WORKING PARTY MINUTES 30 OCTOBER 2014

4.
In future, HDWP updates to the Zone Committee will be made 3-monthly rather
than monthly.
MANAGED AQUIFER RECHARGE: PRESENTATION BY BOB BOWER
Bob Bower gave a presentation to the working group on MAR (See Appendix), providing
background information on MAR, examples of MAR practised elsewhere, lessons learned and
their relevance to the Hinds proposal, and details of the Hinds proposal to date, along with a
possible timeline. The talk covered the following:
4.1 Background: High level summary of managed aquifer recharge – set of physical tools
4.2 Targets and outcomes of MAR for Hinds (quality and quantity)
4.3 Lessons Learnt – Hind River MAR trial (2012)
4.4 Groundwater storage and pressures
4.5 Targeting Groundwater Quality
4.6 Springs, drains, flows and flooding
4.7 MAR Pilot Project: Why, Where, What, When, Who
4.8 Replenishment Scheme: How could a successful pilot be implemented catchment wide.
Comments and questions on specific slides
 25 Outcomes (slide 8). How inclusive are these? They don’t suit the whole community.
 Balancing Groundwater Storage (slide 10). Irrigation is becoming more efficient; farms are
only using a fraction of what is consented. Maybe we are placing too much blame on the
discharge components. General agreement that many factors are at play in the balance of
groundwater storage.
 Water table level (slide 11). This is a wet year. In any given year there is the “noise” of
fluctuations, but with climate change the variations will get more dramatic. In an
unbalanced and declining groundwater storage system, when not managed, the system
will decline. Aim: to increase storage by actively managing recharge and discharges.
 Hinds storage trends – annual pressures (slide 12). The table shows the trends (storage
changes) and noise (pressure response) points. Comment: it is easy to blame extraction
but natural weather cycles would also imact on the trends. There is no one cause; many
things are at play in this system, nevertheless managing flows is crucial.
 Springs – groundwater spillways (slide 13). Increase in storage upgradient, with existing
drainage network, will result in small change (elevation) at spring-heads and drains flows
downstream. The aim is for a slight increase to create perennial base flow without
exacerbating the large pressure reponses associated with storm events. Two other factors
are at play in Hinds: drains – groundwater from top to bottom will safeguard against high
flow effects because they are designed to ‘drain groundwater’; pumping at a springhead
can have localised effects which will affect continuous baseflow conditions.
 MIKE SHE modelling-MAR (slide 15). From Variation 2 documentation, in the Golder MAR
report. This looks at the Valetta side of the catchment. MAR was modelled to be
distributed across the upper and middle portions of the catchment; higher on the plains
to minimise pressure (mounding) too close to drains. A 30 year model shows that over
time putting enough in improves storage capacity. High events increase pressures which
flow through; Groundwater progresses over time. Modelling also indicates that these
changes are minimised at the drains/springs resulting in only small increases in baseflows.
 Infiltration basin – operations (slide 18). MAR aims at the long term trend (storage) not
short term top up (pressure). At the site, local mounding is around the recharge site but
as the pressure response is tracked it gets dissipated. Therefore the MAR site needs to be
far enough away to increase storage in the system and avoid localised mounding near
sensitive areas for drainage. The Golder assessment looked at catchment-wide physical
features to help find the best locations for the Pilot, based on the last 10 years’ data. The
pilot will factor in seasonal variation to avoid operations during the wettest periods.
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HINDS DRAINS WORKING PARTY MINUTES 30 OCTOBER 2014

Hinds River Plains – conceptual model (slide 25). In 2012 a pilot project was carried out
using 10 cumecs on the Hinds River (from RDR spillway). The assessment of the MAR trial
was complicated by an unexpected rain event during the 4 day recharge period. The
pressure reponse to the MAR event was measured out through the aquifer system. The
project highlighted the opportunities for MAR in the Hinds Catchment.
 MAR volumes – the Golder MAR report highlights the need to recognise (with regards to
MAR) the difference between ‘new‘ and ‘replacement’ water relative to MAR modelling
(slide 33). Replacement water is mitigating for decreasing amounts of stockwater losses,
irrigation inefficiencies, and replacement scheme piping. ‘New’ water represents the
amount of water needed to actually work toward improving conditions – more dilution,
increasing groundwater storage.
 Water quality modelling (slides 35-40). The Valetta site pilot would run towards
Ashburton but would not attempt the whole Ashburton Tinwald area.
Brett Painter was asked to describe the project under discussion for the Hurunui area.
Brett stated that options for getting nitrate mass out of the system dilution could include
capture curtains and then denitrification, but this would be difficult and expensive.
Another option being potentially looked at in the Hurnuni is to pump out and reuse
nitrate rich water; reducing additional nitrate fertiliser by the amount already present in
the water.
 MAR pilot (slide 41). The aim is to get water level high enough to show some benefits to
the Tinwald area. The pilot should be sited far enough away so as not to spike the
springhead. The long term aim is to learn a lot, so that more targeted activities can be
planned in locations of particular N concentrations or land uses.
 MAR pilot source water (slide 46). Comment: MAR does not require a huge amount of
water. If the proof of concept works, then further considerations can be made factoring
in water requirements.
General Comments and questions:
 Some of the boundaries or shadings on maps in this presentation are incorrect or
misleading. Action: Bob Bower to correct the maps.
 Who can benefit from the pilot? In the short term there will be some benefits, but in the
longer term trend groundwater will improve.
 What is the time frame? A premonitoring meeting has been set for 31 October. From
there sites need to be finalised and a plan to start pouring water be made. Timing for the
pouring should be at the end of the irrigation season (March), or risk losing another year.
 What is the financial plan? ECan’s budget has been set for the next financial year, but the
concept has been floated and met with general approval for the 2015-2016 budget. This
group needs to request that some of the budget be released to allow for a withdrawal
now. Actions:
 Peter Lowe and Lesley Woudberg will make a formal request to Ecan for early
release of funding.
 Bob Bower will prepare a model with costing and report back to the group’s next
meeting.
5.
TARGETED STREAM AUGMENTATION: BRETT PAINTER
Brett Painter spoke to the group about a pilot project in Selwyn Waihora aimed at getting
cooler, cleaner water into the creek. Pilot testing is being carried out on:
 Deep bore water close to a stream on a property in the Killinchy Swamp area above
Lake Ellesmere. The heavier soils in this area slow down absorption, which means
that an increase in recharge will not have a great impact. At 60 m deep, the bore
water has lower temperature, lower flow, and lower N concentration. An advantage
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HINDS DRAINS WORKING PARTY MINUTES 30 OCTOBER 2014
of this is that it uses a turn on-turn off system that allows quick response. A bank of
bores could become a possibility.
While there are some differences, there could be some comparabilities of this project
with Eiffelton.
 Existing stockwater network. The stockwater network is currently not working very
well. They are looking at moving most of the take to CPW; for example the Irwell site
for recharge basin, near lowland springheads. Utilising existing and new
infrastructure the plan is to manage some stockwater areas for mudfish/native fish
habitats.
Discussion:
 Does the Hinds plan have rules that prevent development such as this? Flexible
solutions are needed.
 Because of Lake Ellesmere, cleaner groundwater is pushed up.
 At the top end N is higher; closer to the lake it is lower.
6.
RIPARIAN MANAGEMENT
Definitions, ideas and recommendations are needed.
Action: Dan Harrison, Ian MacKenzie and Peter Lowe will meet to discuss some ideas for the
next meeting. They will also look at some of the literature used by the Selwyn Waihora
Committee.
A riparian management course is being held in Hamilton on 11-12 November. If anyone would
like to go they should contact Lesley Woudberg.
7.
ACTIONS
Mark Webb, Phil
Everest
Mark Webb, Ian
Mackenzie, Peter Lowe
Peter Lowe, Stuart
Wilson
Prepare a proposal regarding the Lake Hood outflow. Refer item 3.1
and three consensus decisions below.
Identify one drain for enhancement and prepare a proposal. Refer
item 3.1 and consensus decisions below.
Identify mahinga kai areas and prepare a proposal to include water
and signage requirements. Refer item 3.1 and consensus decisions
below.
Consensus decisions
1) Proceed as soon as possible with a trial on one drain to create
made with the full
fish habitat improvements. The intention is identify up to 8 sites on
support of all
one drain then survey fish population, install the artificial habitat
members of the HDWP improvements then in 6 to 8 months survey the fish population
again and in the winter ascertain if the work done will survive high
drain flows.
2)Proceed as soon as possible with 3 sites to enhance mahinga kai.
This would include signage, country stock water supplementation
to the Fords road site and agreement with nearby landowners on
drain maintenance, other sites are Lake Hood outlet and Winslow,
Swamp road corner.
Correct maps in the MAR presentation (refer item 4).
Bob Bower
Recommend that Ecan progress as soon as possible with funding to
Peter Lowe, Lesley
allow the MAR pilot to proceed by the end of this year, the reason is
Woudberg
the need for the HDWP to have sufficient data to make an informed
decision by October 2015.
Discuss ideas for riparian management for the next meeting (refer
Dan Harrison, Ian,
MacKenzie, Peter Lowe item 6).
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HINDS DRAINS WORKING PARTY MINUTES 30 OCTOBER 2014
The meeting concluded at 11.30am.
Next meeting:
Monday 1 December 1:00 pm; MRB Boardroom.
Appendix: Managed Aquifer Recharge (MAR) Hinds Plains – Overview and Pilot Project Discussion:
Bob Bower. On ECan website http://ecan.govt.nz/publications/Council/hdwp-mar-report-bower20141030.pdf
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