Water sustainability for

golf courses

Alex Glasgow, NZSTI

aglasgow@nzsti.org.nz 0274 962 486

2020: Not a good year!

• A “once in a lifetime” drought

• Plus a global pandemic

These events show the need to plan for the worst

The immediate future: plan for water restrictions

▪ Current rainfall pattern –complete ban on use of council water for irrigation?

▪ Develop plans around different scenarios and up-date as new information comes to light (from Water Care)

Your plan will depend on your irrigation water source

• Totally dependent on council water – you could have a severe problem

• Fully dependent on water harvest and own water storage (lake)

• Combination of some water harvest and storage supplemented with council water – you may be dependent on stored water only.

• Your own bore water supply

• Other (treated effluent, establish bore, de-salination!)

Irrigation Water sources

• Fully dependent on water harvest and own water storage (lake)

• Combination of water harvest / storage supplemented with council water

• Your own bore water supply

• Other (treated effluent, establish

bore, de-salination!)

Worst case scenario:Totally dependent on council water and there is no water

• Water greens only

• Part circle sprinklers

• Almost entirely hand watering

• Water source? Buy in

Worst case scenario:No water – have to buy it in

• Tanker – 11000 litres / load = half fills a 22 500 litre (5000 gallon) tank.

• Hibiscus Water, 11000 litres, $160 to $325 – depends on transport distance

Worst case scenario: No water – have to buy it in

Depth of

water

(mm)

Volume/

ha (m3)

Volume/

ha (litres)

No. of 22 500

litre water

tanks

Tanker

loads

Cost at

$160/

tanker

Cost per

100 days

1 10 10000 0.4 0.9 142$ 14,222$

2 20 20000 0.9 1.8 284$ 28,444$

3 30 30000 1.3 2.7 427$ 42,667$

5 50 50000 2.2 4.4 711$ 71,111$

Cost of tanker water to irrigate 1.0 ha of greens

Buying water in:

• This past summer, 2-4 weeks wait to get tanker delivery

• Multiple tankers daily may not even be possible

• Get a supply agreement in place early and even that may fall over.

• Do it yourself?

Greens management: Preparation for limited water

• What you can do is limited – big changes (change grasses) are longer term options

• Wetting agents – start early• Wetting agents with major rainfall events • Raise height of cut / increase turf density in

spring.• Renovate early in spring • Reduce N / increase K during late spring • Acclimate turf in spring

Longer term strategies: Plan for the worst to become more shock proof

• Severe restrictions on water use for irrigation

• Complete bans on the use of pesticides such as fungicides and insecticides

• Complete bans on the use of artificial fertilizers

• Massive increases in the cost of fuel

• Massive increases in the cost of imports or import restrictions

Planning for severe water restrictions

Multi faceted approach needed:

• Plan to decrease the irrigated footprint

• Use the most drought tolerant grasses

• Get better at relevant turf management practices such as developing deeper roots, rewetting dry areas

• Managing player expectations

How much water does a golf course use?

• 15 ha irrigated

• 3mm /day for 100 days

• 45 mega (million) litres

• 2000 22500 litre tanks

• 18 Olympic swimming pools

Use the most drought tolerant grasses

• Avoid grasses that die if not irrigated

• Warm season species (e.g. couch but search for the one that’s right for you)

• New species

What if you don’t water greens?

• Poa annua will die

• Bentgrass will survive and come back with autumn rain

Deep roots give drought tolerance

• Turf quality without irrigation

• Correct construction

• Focus on improving root depth

Define “expectations” and educate players.

• Summer dormant browntopfairway – quality playing surface, doesn’t die, re-grows with autumn rain.

• Define as “normal” and educate.

Define “expectations” and educate players.

• Poa annua dies if water is limited.

• Therefore bentgrass is a better option for greens.

• 10.5 foot plus greens = Poa annua

• To have bentgrass need to target suitable green speed range (e.g. 9.5 to 10.5 feet –defining max. is vital )

Marathon not a sprint

• Changes may be difficult

• Changes may take a long time

• But recent events should be a catalyst