Drought Conditions on Lord Howe Island

Lord Howe Island is suffering from drought. Rainfall in 2018 was 500mm (20 inches) below the longterm average.

The Island has been hit hard this summer. In December we had only 8mm of rain, compared to the long-term average of 100mm, and 117mm in the previous December. There has been no rain at all so far in January and there is no sign of rain in coming weeks.

The Island does not have mains water. Thornleigh Farm, like many others, relies on rainwater. We have a significant investment in catchment, storage and drip irrigation facilitiesto collect and conserve water. Our water reserves have lasted all through December, but with no sign of an end to the drought we have decided to conserve our remaining supply and move the farm to care and maintenance. This means that we will not be able to supply our normal range of fresh produce.

Thank you for your support and understanding. We look forward to getting back to normal after good rains come.

Why don’t we use bore water?

Bore water is used on the Island but the water must be sterilised and desalinated for human use and irrigation. We have a lovely old well on the property. We can sterilise the water with in-line ultraviolet filtration, but we do not favour desalination because it requires large amounts of power and produces toxic waste as a by-product which is poisonous to land and marine life.

Getting Tanked

Acquiring water is perennial challenge on Thornleigh Farm. We don’t bore into Lord Howe Island’s water table, as it is already under substantial pressure. Rain is to infrequent and inconsistent to sustain the gardens on its own.

Our solution? Capture rainwater, store it, and distribute it using drip-irrigation. That means tanks. Lots of them. We just installed a new 60,000l TankWorks tank, taking our total storage capacity somewhere north of a quarter of a million litres.

The new tank sits off the old butcher shop, plumbed to the shop roof. Existing tanks are plumbed off the garage and farmhouse, which means we now draw water off most of the major structures on the farm.

 

Droughts and Flooding Rains

I love a sunburnt country,
A land of sweeping plains,
Of ragged mountain ranges,
Of droughts and flooding rains.
I love her far horizons,
I love her jewel sea,
Her beauty and her terror –
The wide brown land for me!

Lord Howe Island lies several hundred kilometres off the Australian mainland. Yet Dorothea Mackellar’s words ring as true here as they do in Broken Hill, Bourke, or beyond.

Summer was tough this year. At Thornleigh Farm, we didn’t begin well. Two factors loomed large over the property as the temperature rose:

First, the house roof. The house roof is the primary catchment area for the farm’s water supply. During the months leading up to summer, the roof was being replaced: Little water was being collected.

Second, an error led to the loss of a substantial amount of water from one of our massive water tanks. An error we will learn from, and never repeat again!

Had the summer been mild, we might have recovered. It was not. Across the whole island, grass browned, trees wilted, and streams dried up. Water reserves maintained by the local authorities were called on by the community.

Summer drought Lord Howe Island Thornleigh Farm
Luna standing in a dry paddock in summer – Her diet was supplemented with banana leaves

Our farming strategy depends on being able to irrigate the gardens by drawing down large reserves of rainwater during dry periods. With our tanks running dry, we could not sustain the gardens. Irrigation had to stop. Water was preserved for the house and the animals. Our crops wilted.

This was a trying time. Yet we have emerged stronger. Over the past months, replacement of the house roof has been completed. Huge tropical gutters, installed along extended eves, channel water towards enlarged downpipes and into newly refurbished underground tanks.

Water tank lord howe island
Re-concreting, sealing, and lining an underground tank

We can now hold tens of thousands of litres of water in those tanks. Submerged pumps, automatically actuated by float switches, drive water to the main (and much larger) above ground storage tanks whenever the water rises above preset levels.

Water tank Lord Howe Island
A submerged pump sitting inside a newly lined underground tank

The difference this work has made cannot be overstated. At a personal level, I can attest to the dread I used to feel when heavy rain began pelting at the old house roof. Water would flow in through the ceiling, the windows, and towards the doors as it ran past damaged gutters and through rusted roof sheeting.

Now, the roar of rain can be enjoyed again. It means only one thing: A torrent of water flowing into our water tanks. And has the water ever poured! Big low pressure systems arrived in April, bringing heavy rain and taking our tanks from empty to full in no time.

I love this sunburnt country, especially this island portion. Lord Howe is a jewel upon the sea. A ragged mountain outcrop, joined by little mini-plains. Now, at Thornleigh, we will mitigate her droughts by harnessing the flooding rains.