STATEMENT OF EVIDENCE OF DANIEL ROBERT WATSON ON BEHALF OF THE HAWKE’S BAY WINEGROWERS’ ASSOCIATION

& GIMBLETT GRAVELS WINEGROWERS’ ASSOCIATION

STAGE 2 MATTERS

25 JANUARY 2019

Counsel instructed:

J D K Gardner-Hopkins Phone: 04 889 2776 james@jghbarrister.com PO Box 25-160 WELLINGTON

Solicitors acting:

Alison McEwan Phone: 06 835 8939 Fax: 06 835 3712 PO Box 446 NAPIER

BEFORE THE SPECIAL TRIBUNAL FOR THE NGARURORO AND CLIVE RIVERS WATER CONSERVATION ORDER AT NAPIER

IN THE MATTER of the Resource Management Act 1991 (“Act”)

AND IN THE MATTER of a Special Tribunal appointed

under s202 of the Act to consider an application for a Water Conservation Order

THE SPECIAL TRIBUNAL: Richard Fowler (Chair) Alec Neill (Member)

Dr Roger Maaka (Member) Dr Ngaire Phillips (Member) John McCliskie (Member)

1

1 Qualifications and experience

1.1 My full name is Daniel Robert Watson.

1.2 My role is National Vineyards Manager for Craggy Range Vineyards.

1.3 Qualifications: B.Sc Agriculture, Assoc. Degree Winegrowing, Masters Viticulture, Masters in Business (Finance).

1.4 Summary of experience:

i Commenced working in the wine industry in Australia in 1992 for

Coldstream Hills Winery (1.5 years), De Bortoli (6 months) and Long Gully Winery as an Assistant manager (2 years).

ii Accepted role as Vineyard manager in Western Australia for Blackwood Valley Wine Partnership for 3 years.

iii Commenced employment with Delegat’s Wine Estate in 1999 as

Assistant manager in Hawkes Bay in role for 2 years, then promoted to Vineyard manager in 2001 responsible for all Hawkes Bay

vineyards.

iv Resigned in 2004 and accepted a role as Chemical adviser with

Northern Territory Primary Industries, remained in role until 2007.

v Accepted position as Vineyard manager in Marlborough for

Matakana Estate in 2007, remaining in role until 2011.

vi Accepted position as vineyard manager for Craggy Range in

Martinborough in 2011, remained in Martinborough to 2015 and promoted to Regional vineyard manager for Craggy Range in 2015

based in Hawkes Bay.

1.4 My evidence supports the submission by Hawkes Bay Winegrowers’ and Gimblett Gravels Winegrowers’ Associations (“Winegrowers”) on the draft

Water Conservation Order (“WCO”) for the Ngaruroro and Clive Rivers. The Winegrowers oppose any WCO in regards to its application to the Lower

Ngaruroro River. The Craggy Range submission sought the same outcome as the Winegrowers, for similar reasons.

2

2 Scope of evidence

2.1 This evidence addresses the following matters:

i Role and practice of irrigation in the Hawke’s Bay wine industry,

using Craggy Range as an example; and

ii Vineyard irrigation best practice and innovations, illustrating the

importance of closely controlled irrigation in winegrape production.

3 Introduction

3.1 Irrigation is a key tool in the vineyard to manipulate vine growth and development.

3.2 As water is a scarce resource and continues to increase in scarcity, it is the responsibility of every vineyard manager to use water judiciously in an environmentally sustainable manner. Best practice irrigation management

involves using the most up to date soil moisture monitoring, irrigation scheduling and irrigation systems available in a targeted manner to influence

target grape quality and yields. The viticulture industry has been at the forefront in developing new irrigation technologies in response to increasing

market demand for premium to super premium wines produced in an ecologically sustainable framework.

3.3 The information presented in this report summarizes what Craggy Range is doing in their Hawkes Bay vineyards to increase grape quality while

minimizing water use at every step in the grape production process.

4 Irrigation Volumes and Practical Considerations – an overview

4.1 Gimblett Gravels vineyard

a There are two row spacing’s on the vineyard, 1.6 m applying 2.5 mm/hr and 2.0 m rows applying 2.0 mm/hr. Refer to Annexure 1 for a summary

of dripline specifications.

b The soils on the property are unique in that the water holding capacity is

very low due to a high percentage of stones, sands and very fine silts. Soil pores are very large and consequently do not hold a large volume of

water, this compares with the Kidnappers vineyard in Te Awanga which

3

contains fine clay/silt comprising many small soil pores that retain

moderate to high volumes of soil water.

c Topsoil on the Gimblett Gravels vineyard comprises fine silts and stones

therefore water is quickly lost in the upper profile. For this reason irrigation normally starts quite early in the season once the topsoil begins to dry. In

general, irrigation would start sometime in October or early November depending on seasonal conditions, with the stonier areas and younger

vines having priority. The siltier blocks would generally require irrigation 10-14 days after the earlier blocks. The exact start date for irrigation is

determined by soil moisture probes.

d As a general rule, around 1.0 mm/day would be required in October (1.6 m rows – 2.8 hrs/week), potentially increasing to 1.5 mm/day in November

pre flowering (4.2 hrs/week on 1.6 m rows).

e Once fruitset has occurred and canopy development is complete, usually

mid December irrigations in red varieties are withheld at our Craggy Range vineyard for a period of at least 10-14 days depending on

conditions. The aim is to stop shoot growth and encourage the vine to begin a fruit development phase. It is vitally important that a period of quite

high stress occurs to minimize berry size and halt vegetative growth.

f It is normal over this period to observe tendrils wilting, leaves facing away

from the sun in the afternoon and vines appearing ‘wilted’. It is very important that the soil probes are checked daily and the blocks are walked

regularly to ensure that an over stress situation does not occur. If the moisture stress is too extreme the vine may start dropping leaves, which are important for fruit ripening later in the season. In extreme cases vines

can begin senescence early or even die.

g It is also important that in lower vigour blocks that are showing delayed or

incomplete canopy development, water stress after fruitset is minimized.

h Young developing blocks also should not be subjected to the high stress

regime as this can delay vine development.

i In Chardonnay blocks a mild period of water stress is required to slow

canopy growth however the time period and degree of water stress is much less than in red varieties, as berry size is not as important and we

4

also need to protect the basal leaves as they are important in minimizing

sunburn on the berries.

j Approximately 10-14 days after fruitset, once the period of stress has

occurred in red varieties, irrigations can be increased.

k As a general rule, 2.0 – 2.5 mm/day will be required, equating to 5.6 – 7

hrs per week in 1.6 m rows. Run times of 2.0 – 2.5 hrs per irrigation are preferred to ensure root growth is encouraged at depth.

l At this stage of the season the water reserves deep in the profile are virtually zero and the vine is completely dependent on water from rainfall

or irrigation. If a sustained period of very hot weather occurs, irrigations up to 3.0 mm/day may be required, which is 8.4 hrs per week (2 -2.25 hrs every 2nd day).

m It is important that irrigations are scheduled over weekends as required and blocks are checked over the weekend to ensure no ‘misses’ in the

cycle. Due to the very stony nature of the soils, if a valve is faulty and not identified quickly, rapid vine defoliation can occur resulting in fruit quality

deterioration and possible fruit rejection. It is imperative that all blocks are regularly checked to ensure valves are operational, and blocks are walked

post irrigation cycle to check for wetting under vine. Soil probes can help identify if irrigations have occurred in blocks containing soil probes

remotely.

n At the onset of veraison (late January/early February) the vine undergoes

a rapid period of growth and requires increased volumes of water for berry ripening. We actively avoid any water stress over this period to ensure berry sugar accumulation and colour development is not hindered. The

volume of irrigation applied is dependent on the crop loading and seasonal conditions. In moderate to high crop situations with minimal inputs from

rainfall, irrigation volumes can peak up to 2.5 – 3.0 mm/day. This irrigation regime would continue for at least 2 weeks until colour development is

complete.

o Approximately 7-10 days out from harvest in late March or early April,

irrigations can be tailed off to prevent possible berry dilution and delayed maturity. Some water stress just before harvest is not necessarily a bad

outcome in terms of fruit quality as physiological maturity can be

5

enhanced. Once harvest has occurred, assuming conditions are dry,

irrigations post-harvest are recommended at a reduced amount to maintain leaf condition and promote carbohydrate partitioning in the

permanent parts of the vine.

p The current Craggy Range water consent allows for just over 3.0 mm/day

on the Gimblett Gravels vineyard, 8.4 hrs/week in 1.6 m rows, 10.5 hrs in 2.0 m rows.

Figure 1: soil moisture in block 24 Gimblett Gravels Merlot from 30th September 2015 to 30th November 2015. Note the regular irrigations over this period maintaining soil moisture in a comfortable zone.

Figure 2: Soil moisture in block 24 GG from December to end February. Note the drying phase from the 10th December to the 20th December.

6

Figure 3: Soil moisture in block 14 GG from 1st October 2015 to 1st February 2016. Note the drying phase throughout December. 4.2 Kidnappers vineyard

a Kidnapper’s irrigation is treated completely differently from the Gimblett Gravels vineyard. Dripper spacing is 0.6 m, 1.6 lts per hour providing 4.8

lts/hr/vine.

b The soils retain a reasonable amount of water and tend to take time to

warm up in spring therefore irrigations are not normally required early in the season. Soil probes are monitored regularly throughout this period to

help guide when irrigations should commence.

c Irrigation would normally commence just before flowering towards the end

of November however this is heavily dependent on seasonal conditions, if rainfall is above normal irrigations could be delayed. As the vineyard is

remote from the Gimblett Gravels management base, irrigation monitoring can be problematic resulting in potential missed irrigations and slow

response to faults. The Harvest brand remote water meters are a useful tool to monitor if irrigations are occurring, as well as the soil probes.

d Early season in November and early December, irrigation volumes

approximating 0.5 – 0.75 mm/day would be required, 3.0 – 5.0 hrs/week.

e Deeper irrigations are preferred on this vineyard as the under-vine sward

rapidly depletes soil moisture in the topsoil however the controller only allows a maximum of 2 hr cycles which is prohibitive. Short irrigations will

7

water the under vine grass however provide little benefit to the vine. Based

on 3 – 5 hrs/week, 3 applications of 1.5 hrs would normally be sufficient.

f Once fruitset is complete, a short period of minimal irrigation is required to

slow shoot growth.

g Towards the end of December and into January and February, irrigations

would be increased to around 1.0 mm/day, or 6 hrs/week (3 x 2hrs).This volume sounds high, however we need to allow for competition from the

under vine sward. The soil probes are monitored closely, if a wetting phase is noted over time, irrigations would need to be reduced.

h Approximately 10-14 days from harvest irrigations should be stopped to promote maturity. Refer to figure 6 below for a typical soil moisture trend.

i The consent allows for 44.67 cu.m/ha/day, or 4.4 mm/day.

Figure 4: Soil moisture at the KV vineyard from 1st November 2015 to March 2016. Note the drying phase towards the end of December and in March.

8

Gimblett Gravels water use

Season Total water use m3 m3/ha Consent m3

% Variance

17/18 163218 2024 251213 65% 16/17 149978 1860 251213 60% 15/16 144345 1790 251213 57% Kidnappers water use

Season Total water use m3 m3/ha Consent m3

% Variance

17/18 21819 1455 71585 30% 16/17 18740 1249 71585 26% 15/16 12747 850 71585 18%

Table: Total water use previous three season Gimblett Gravels and Kidnappers vineyard.

j Table 2 summarizes water use on both the Gimblett Gravels and Kidnappers vineyards over the previous three season. Actual water use is

well below consented levels on both properties through the use of drip irrigation and advanced irrigation scheduling and monitoring tools.

k The irrigation practices employed at Craggy Range would generally be in line with standard irrigation practices in the viticulture industry.

5 Application methods

5.1 Irrigation application on both the Gimblett Gravels and Kidnappers vineyards is via drip irrigation which has the flexibility to apply varying volumes of water

very precisely and efficiently with minimal evaporation from the soil surface.

5.2 Drip irrigation applies water along the vine row creating a targeted ‘sausage’

of wetted soil which the vine roots can readily access. This promotes a concentration of vine root growth and weed growth in the wetted area and

tends to discourage root growth in the drier mid row area.

5.3 This is not ideal from a fruit quality perspective as the drip irrigation, if not

tailored to the particular soil type can result in soil nutrients being poorly utilized as the vine is concentrating its roots in a narrow strip of soil under

vine. This area tends to be ‘mined’ of nutrients while the mid row area is poorly utilized.

5.4 When the Gimblett Gravels vineyard was planted in 1999/2000 in an effort to

promote vigorous root growth throughout the soil profile, the soil was ripped

9

multiple times both down the row and across the row to open up the soil

profile and remove compacted soil layers that were evident.

5.5 Fertilizer application via the drip system was minimized in an effort to

encourage a branching root system rather than a concentration of root hairs close to the surface in the under-vine area. Although this practice reduced

vine growth in the early years, we now see that over time the vines have developed very deep root systems spread throughout the soil profile and

consequently are not as reliant on supplementary irrigation early in the season and are able to withstand periods of water stress without significant

impacts on yield and quality.

5.6 Drip irrigation is more capital intensive than traditional irrigation systems such as overhead sprinkler and flood irrigation systems and requires advanced

filtration and control systems. Correct site preparation prior to installation of the irrigation system is important to ensure there are no impediments to root

growth. Drip systems also require an elevated level of management inputs to ensure the correct amount of water is applied at the right time.

5.7 If managed correctly drip irrigation is the most efficient method to apply water in a vineyard and results in much lower volumes of water applied compared

with sprinkler and flood systems.

5.8 Drip irrigation can also be easily automated which allows for precise water

applications to match vine water requirements. An irrigation controller capable of logging water applications and storing different irrigation programs to suit

different varieties and growth stages is used on both vineyards which can be accessed remotely.

5.9 This provides a very powerful tool to target periods of wetting and drying at

key times in the season to optimize both fruit quality and yield.

5.10 There is now technology available to link soil moisture probes with irrigation

control systems enabling automated application once soil moisture levels reach pre-determined refill points. Although this technology is not currently in

use on Craggy vineyards it does have the potential to improve irrigation application efficiency even further.

10

6 Innovations

6.1 Controlled Deficit irrigation

a Controlled Deficit Irrigation (CDI) or regulated deficit irrigation has been

used for many years in premium quality viticulture to optimize water use efficiency while also reducing vegetative growth and improving fruit quality

with zero or limited effect on yield.

b The practice involves imposing consistent and moderate levels of water

stress during key phases of vine growth and development. The Australian wine grape industry was instrumental in completing much of the early

pioneering work in this area driven by a shortage of water in most of the grape growing regions.

c As many viticulture regions in New Zealand such as Hawkes Bay are

experiencing sustained water shortages, CDI practices are becoming common place and considered normal practice.

d CDI is heavily reliant on the ability to precisely control the timing and quantity of irrigation applied to the vineyard which well-designed drip

systems are ideally suited.

6.2 CDI Strategies

a The timing of water stress is closely linked to the growth stages of the vine. The key growth stages are:

i Phase I – occurs following budburst to just after flowering. Shoot growth is followed by berry growth and is extremely rapid in phase I

and consequently water stress early in this phase can reduce shoot growth and disrupt flowering significantly. CDI strategies are not generally imposed over this period.

ii Phase II – occurs from just after flowering/fruitset to veraison and is characterized by a period of rapid berry growth and slowing shoot

growth. CDI can be used to restrict berry size and limit vegetative growth providing fruit quality benefits. Depending on the level of

water stress yields can be reduced slightly. Craggy Range target this period in all red varietals by withholding water for a 2-3 week

period to a point where severe water stress appears.

11

iii Phase III – this occurs from about veraison onwards and is

associated with an increase in berry size, accumulation of sugars, a decrease in acidity and increasing pH, berry softening and a colour

change most pronounced in red varieties. Water stress during this period can increase wine colour, aroma and flavour while potentially

reducing yield and sugar accumulation. Normal practice on the Gimblett Gravels vineyard in red varieties is to increase water

application at veraison over a 2 week period, then gradually reduce irrigation approaching harvest. In Chardonnay more water is applied

during the post veraison stage as the aim is to minimise any water stress due to the impact on berry size and flavor compounds.

6.3 Sub-surface Irrigation

a The use of sub-surface drip irrigation is increasing in vineyards and can reduce issues related to significant under vine weed growth and

concentration of the vines root system to the drip line wetted zone particularly if the drip line is installed in the mid row area.

b In addition, plant water uptake can be higher under sub-surface compared with surface irrigation systems. Advancements in recent times utilizing a

physical barrier over the dripper or drippers impregnated with herbicide reduce root intrusion which can be a problem in sub surface systems. The

drip line is typically installed 200-300 mm below the soil surface.

c Water use efficiency is improved as evaporation from the soil surface is

reduced, also water used by weeds is reduced as weeds are not encouraged in the under vine area. Large vineyards in Hawkes Bay have sub surface systems in place and this practice is gaining in popularity as

dripper technology improves. Sub surface systems provide the potential to increase irrigation efficiency even more than standard drip systems.

6.4 Monitoring

a Water is an extremely powerful tool to influence both grape quality and

yields.

b The objective of the irrigation scheduling program is to apply the minimum

amount of water to maximize fruit quality and yield within target levels.

12

c Over-watering represents a waste of a limited scarce resource, potential

dilution of quality, reduce yields and result in excessive pumping costs. Under-watering can restrict quality through limiting the amount of leaves

providing photosynthate to the developing berries resulting in delayed, uneven ripening, incomplete flavor development and imbalances between

sugar and acid levels in grape berries.

d Irrigation scheduling is a complex process and is based on a number of

monitoring tools including:

i Weather data and forecasts – we use multiple weather forecasts

from specialized suppliers such as Metris and Weatherstation forecasting services to provide the most accurate site climate forecasts. Combined with these forecasts we have site weather

stations on each vineyard which measure rainfall, temperature and humidity. By analyzing this information we can assess daily

evapotranspiration losses and future irrigation requirements.

ii Soil moisture probes – There are 8 soil probes located around the

Gimblett Gravels property located in representative blocks and soil types providing volumetric water content readings of the soil. These

probes utilize Time Domain Transmissometry technology and log soil moisture regularly throughout the day providing live data.

iii Water Pressure Chamber – This technology measures water potential and represents a direct measurement of vine water stress

allowing extremely precise irrigation scheduling. The advantage of this method is that no assumptions have to be made regarding root distribution or the relationship between soil water content and vine

uptake. We take water potential readings in the critical period approaching flowering and throughout the fruitset/post fruitset period

to allow precise sustained water stress to be imposed.

iv Visual observations of vine water status – blocks are typically

checked every day or every second day during summer for signs of water stress such as slowing in shoot and lateral growth, cupped

leaves, drooping/blackened tendrils and basal leaf yellowing.

e By combining direct observations of vine water stress and water pressure

chamber readings with indirect methods such as soil moisture probes and

13

weather data, precise irrigation scheduling is possible which ensures vines

are not over- or under-watered and the water resource is being utilized efficiently.

f As water is a very powerful tool in influencing both grape quality and yield, by utilizing a number of scheduling tools we are able to optimize irrigation

as a key management tool during periods of the season when conditions dictate irrigation inputs.

7 Conclusions

7.1 Craggy Range utilises drip irrigation technology to enable precise, targeted

application of water with the objective to impose water stress during key stages in the season. Irrigation scheduling utilise a number of methods including

weather forecast and weather station monitoring, soil moisture probes, water potential readings and visual observations of water status. Recent innovations

in irrigation application technology includes controlled deficit irrigation and sub surface irrigation which offers the potential to reduce water use with minimal

detrimental impacts on fruit quality and yields. These practices and innovations are relatively widespread in the viticulture industry in the region.

Daniel Watson

25 January 2019

1

Annexure 1 – Craggy Range vineyard irrigation design specifications