Short answer: Shade balls in Australia are available from Evap.co, the shade ball brand of Big Ditch. A close-packed cover of 100 mm balls needs about 116 balls per square metre and costs US$44 per square metre excluding GST, with freight from the port quoted separately. Independent trials of full covers measure evaporation savings of about 40 to 75 percent.

Evap.co is the shade ball supply arm of Big Ditch, the dam construction and repair business run by Lindsey Hughson across NSW, Queensland and Victoria. Evap.co is not affiliated with EVAPCO, Inc., the cooling tower manufacturer. This page covers what you get, how many balls your storage needs, what it costs and how to order. For how shade balls work and the research behind them, read what shade balls are and how they work.

Shade balls Australia: what you get

A shade ball is a hollow plastic sphere that floats on stored water and, packed edge to edge, shades the surface and shelters it from wind. Evap.co supplies 100 mm balls.

Specification	Evap.co shade balls
Diameter	100 mm
Weight	About 40 g per ball
Balls per square metre	About 116 (close packed)
Surface coverage	About 91% of the water surface
Packing	Woven bags or jumbo bags
Maximum per 40 ft container	63,480 balls
Lead time	About 30 days from order confirmation
Delivery	To port, usually Sydney. Freight to site quoted separately

Close-packed 100 mm balls sit about 116 to the square metre and cover about 91 percent of the water surface. The other 9 percent is the small gaps between the balls.

Surface coverage is not the same as evaporation saving. Independent trials summarised in our research article measured savings of about 40 to 75 percent under full or near-full covers. The 85 to 90 percent figure often quoted for Los Angeles was an operator estimate, not an independent trial.

How many shade balls do you need?

Multiply the water surface area in square metres by 116. Measure the dam at the level it usually sits for most of the year, not at full supply, because that is the area the balls will cover. For an irregular dam, use the longest length and the average width, or follow our guide to measuring your dam surface area.

Storage	Area (m²)	Balls needed	Price ex GST (US$)	Approx. price ex GST (A$)	40 ft containers
Small tank or turkey nest, 10 m × 10 m	100	11,600	US$4,400	A$6,260	0.2
Small farm dam, 30 m × 20 m	600	69,600	US$26,400	A$37,530	1.1
Medium farm dam, 50 m × 40 m	2,000	232,000	US$88,000	A$125,110	3.7
Process or irrigation storage, 100 m × 75 m	7,500	870,000	US$330,000	A$469,150	13.7

Australian dollar figures use an exchange rate of A$1 = US$0.70, as at late October 2026. The shade ball cost calculator uses the current rate and adds GST. Freight and installation are extra.

What do shade balls cost in Australia?

Evap.co shade balls cost US$44 per square metre of covered surface, excluding GST. That works out to about A$63 per square metre at late October 2026 exchange rates, or about 54 cents per ball.

Three things change the final figure:

Exchange rate: the price is set in US dollars and fixed in Australian dollars when your order is confirmed.
Freight: balls ship to port, usually Sydney, and road freight to your site is quoted for your address.
Quantity: a full 40 ft container holds 63,480 balls, enough for about 547 square metres.

To judge value, compare the price with the water saved, not with the area covered. Our guide to shade balls versus floating covers sets out the cost per megalitre saved for each type of evaporation cover.

Where shade balls work best

University of Southern Queensland researchers found that floating modules, which include shade balls, must cover 88 percent of the surface to reduce evaporation by 70 percent. They judged them suited to storages up to about 5 hectares (Pittaway, Scobie and Schmidt, 2023).

Lined storages, tanks and turkey nest dams with a steady water level
Small, high-value storages where every megalitre counts
Odd-shaped storages where cables or a fitted cover would be hard to install
Storages where you want to block sunlight to limit algae growth

Shade balls are a poorer fit for:

Earth dams that dry out, because balls can stick in the mud and fail to re-float
Dams with an open spillway, unless the balls are contained, because they can wash out or block it
Very exposed sites, where strong wind can push balls ashore
Large dams, where the cost per megalitre saved rises well above other options

These limits come from the 2020 Assessment of Evaporation Mitigation Technologies in Queensland by the University of Southern Queensland. If you are not sure which option suits your dam, ask Big Ditch for advice before you order.

How to order Evap.co shade balls

Measure the water surface area and enter it in the shade ball cost calculator.
Send the estimate to Big Ditch from the calculator, with your delivery address.
Receive a firm quote with the exchange rate and freight to your site.
Confirm the order. Balls ship in about 30 days.
Tip the balls onto the water from the bank. They spread and pack themselves.

Frequently Asked Questions

How many shade balls do I need per square metre?

You need about 116 balls of 100 mm diameter for each square metre of water surface. That close-packed layer covers about 91 percent of the surface. A 600 square metre dam needs about 69,600 balls.

How much do shade balls cost in Australia?

Evap.co shade balls cost US$44 per square metre excluding GST, about A$63 at late October 2026 exchange rates. GST, freight from port and any installation are extra. The calculator gives a current figure for your dam size.

Do shade balls need to be installed?

Shade balls need no frame, cables or anchoring. They are tipped onto the water and spread across the surface on their own. Storages with spillways or outlets may need a floating boom or screen to keep the balls in place.

Updated October 2026 to add Evap.co specifications, pricing, sizing examples and ordering steps.

Want shade balls sized and priced for your own storage? Book a site inspection with Big Ditch and we will measure the surface and quote freight to your site.