Setting up a backup water supply for dry seasons

March 16, 2025

Running low on water on a rural block is not really a weather problem, it is a planning problem, because the dry stretch was always going to turn up eventually and the only question was whether you had worked out your numbers before it did. Once the tanks are down and you are ringing around for a truck, every option left is an expensive one.

So this is the thinking I would do well before it gets to that, and I will be straight with you about which bits of it we can help with and which bits we cannot.

Start by knowing what you have actually got

Most people can tell you how many tanks they have and very few can tell you how many litres are in them right now, which is the number that matters. Get the capacity of each tank written down somewhere, then work out roughly what the household goes through in a week. A dipstick, a sight tube or just a tap on the side with a piece of timber down it will tell you more in five minutes than guessing will all summer.

Once you know both numbers you can answer the only question worth asking, which is how many weeks you have got left at the rate you are going.

The arithmetic on what you can catch

This one is worth knowing because it makes the decision for you. Every millimetre of rain that falls on a square metre of roof is one litre of water, so a 200 square metre roof catches 200 litres for every millimetre that lands on it. Work out your roof area once, and every forecast turns into a number instead of a feeling.

What that arithmetic usually shows people is that the roof is not the limiting factor. The storage is. A big roof feeding a small tank sends most of a good downpour straight out the overflow and down the driveway.

Where we fit, and where we honestly do not

We do not sell water tanks and we do not sell pumps, so the storage and the pressure end of your system is coming from somewhere else and I am not going to pretend otherwise. What we do have is everything that connects it all up and everything that cuts what you use, which is the part most people under invest in.

So poly pipe in 13mm, 19mm and 25mm off the roll, the fittings and adaptors to join it, thread tape, hose clamps, in line filters, drip line, tap timers and the mulch that keeps the water in the ground once you have put it there. That is the plumbing and the efficiency half of the job, and it is genuinely ours.

Cutting what you use is the cheapest water you will ever find

A litre you do not use costs nothing and needs no storage, which makes this the first place to look rather than the last.

Get the water to the roots instead of the air. Drip line and inline dripper tube put water at the base of the plant where it soaks in, rather than a sprinkler throwing most of it into a hot breeze.
Water when it is cool. Early morning or evening watering loses far less to evaporation than the middle of the day, and a tap timer means you do not have to be standing there at six in the morning to do it.
Mulch everything. A decent layer of mulch on a garden bed slows evaporation out of the soil and keeps the root zone cooler, and it is the single easiest thing on this list.
Chase your leaks. A weeping joint or a dripping trough valve that you have stopped noticing will quietly empty a tank over a few weeks. Walk the lines when the pump is off and look for wet ground where there should not be any.
Shade what struggles. Shadecloth over the veggie patch cuts the water those beds need by a serious margin, and it is sold by the metre so you only buy the width you want.

Sort a second source before you need one

A backup you have to arrange in a hurry is not really a backup. If there is a bore or a dam on the place, find out now whether the water is fit for what you want to use it for, because bore water varies enormously and testing it is a lot cheaper than finding out through a dead vegetable patch. Greywater off the laundry can take a load off the garden too, and it has its own rules about where it may go, so that is worth a look before you plumb anything.

For drinking water, we run a Mt Lofty water exchange at the shop, so you drop the empty and take a full one, and that covers the kitchen end of things regardless of what the tanks are doing.

Keep the plumbing sound so the storage counts

None of the above matters if the line from the tank to the house is limping. Check your fittings for weeping, replace the thread tape on anything you have had apart, make sure your hose clamps are tight rather than merely present, and put an in line filter ahead of anything with a small orifice in it so grit out of the tank is not the reason your drippers block up.

Tank and pump maintenance are their own jobs and both have a post of their own, linked below, because they deserve more than a paragraph here.

The real cost of leaving it

The reason to do this on a quiet weekend is that the alternative is doing it on the worst possible day, and the worst possible day always costs more. A tap timer and a roll of drip line is an hour of your time. A carted load of water and a rushed decision about a tank is a day you will not get back and a bill you did not plan for. Your time is worth something, and the day everything is already going wrong is the day you have least of it.

Shop related products

Pope Simple Set Tap Timer. Waters at the right hour so you do not have to be up for it.
Pope Drip Eze 13mm x 30m. Inline dripper line that puts the water at the roots.
Pope Hold Down Stakes, 10 pack. Keeps the drip line where you laid it.
Pope 12mm Brass Tap Adaptor. Brass rather than plastic on the tap that gets used every day.

Did you know we also stock low density poly pipe in 13mm, 19mm and 25mm by the 25 metre roll, poly fittings and adaptors, thread tape, hose clamps, 13mm and 19mm in line filters, soaker hose, pea straw and lucerne mulch, and shadecloth by the metre in 50, 70 and 90 percent. Most of that is not on the website, so give us a ring on (08) 8536 4333 to check what is on the shelf. We also deliver, which is worth knowing when it is rolls and bales rather than a bag you can carry.

More from the block

I am the sort of person who knows where every tap on the place is and still has to go and look at the tank to tell you what is in it, which is exactly why the numbers belong on paper.

Cheers,
Candeece

Candeece