A Homeowner’s Guide to Rainwater Tanks

Most people don’t really think about where their water comes from until there’s a drought or they get a massive water bill. 

In those times, a rainwater tank goes from being a nice idea to an asset. Today especially, many people are considering installing a water tank. Yet, everyone should be informed before they make a decision like that. Here’s some information to consider before you buy.

Why Rainwater Tanks Are Worth Considering

The average Queensland household spends around $1,200 a year on water. And with the cost of living crisis, that bill can put a real strain on families. But a properly installed rainwater tank has been shown to cut water use by up to 50%, depending on your tank size, how much it rains, and how you use the water.

It’s not just about saving money, either. Collecting your own rainwater helps reduce runoff, takes the pressure off the council’s supply, and gives you more control over how and when you use water. But like everything in life, there are pros and cons to it. Let’s weigh it up.

The Pros of Installing a Rainwater Tank

Reduces Runoff and Flooding Risk

Instead of water running off your roof and straight onto the street (or into a clogged drain), it gets stored in your tank. This helps prevent streets and drains from being overloaded, especially during storms. In communities like Rockhampton that are close to waterways and at risk of seasonal flooding, having enough tanks in local homes can help reduce the damage.

Extra Water During Restrictions

If you can remember back in 2020,  people were told not to wash their cars or water the garden during daylight hours. When water became a limited resource because of the drought, folks with rainwater tanks weren’t as restricted. That extra supply doesn’t show up on your utility bill and can keep your plants alive even when everyone else’s grass is turning yellow.

Useful in Bushfires

In hotter months, bushfires become a real risk in regional Queensland. If you’ve got a larger water tank on your property, it could help in a firefighting effort. Having access to this extra water supply may help save more lives and local property if needed.

Saves Water

Australians tend to have a bit of a soft spot for saving water. Even the person who invented the dual flush to save water was an Aussie. And the reason is that it can get dry. Really dry. So saving water isn’t just about cutting costs; it’s about doing the right thing. By using tank water for things like gardening, and washing your car, you reduce demand on the strained public supply when needed. In residential usage, about 9% or 117 billion liters can be saved annually through water tanks.

The Dreaded Water Bills

Nobody enjoys opening the mail and seeing a crisp white envelope. Nine times out of ten, it’s just another bill. But when your tank takes a lot of your daily water needs, the difference is noticeable. According to the ABS, this extra conserved water that I mentioned before meant a saving of $540 million dollars for Aussie households.

In some areas, usage reduction is as high as 63%, especially outside major urban centers. That’s a pretty big win.

Rainwater Is Softer

Compared to tap water, rainwater carries a lot less minerals in it, like calcium and magnesium. While these are safe to drink, they can build up in pipes and appliances over time. Using rainwater, for example, can help overcome some of the challenges that hard water can have on your plumbing and appliances. (Here’s more in-depth on what hard water does if you’re interested)

The Cons to Be Aware Of

Upfront Cost

Like any home improvement, you’ve got to spend a bit to save in the long run. Tanks vary in price based on their size and material. For example, it is more expensive to set up a concrete or fiberglass rain tank than a plastic one.

The initial cost is definitely a factor you need to consider. But it’s like buying shares or solar panels, they can have an upfront cost but save you money over time. So what you really need to ask is whether will it pay for itself over time. Some areas even offer government rebates so check what’s available locally.

Maintenance Is a Must

Rainwater tanks aren’t “set and forget.” You’ll need to clean them out, check for cracks or leaks, and make sure mosquitoes aren’t breeding inside. 

Make sure to:

• Clear gutters
• Trim overhanging vegetation
• Inspect tank and pipes for wear and tear

Disinfecting with sodium hypochlorite is also good practice. 

Takes Up Space

Everything that exists takes up room. And it’s no different for a rainwater tank. They can take up space in your yard and might not be the prettiest feature. 

However, there are slimline models available now that hug the wall or fence line, and smart landscaping can help it blend in. And underground models are much less noticeable.

Water Supply Is Inconsistent

Rain isn’t guaranteed. In dry seasons, your tank might run dry just when you need it most. But even a partly full tank gives you options and in wet months, it’ll fill back up quickly. 

Not Always Safe to Drink (Without Treatment)

Rainwater is great for the garden and cleaning, but don’t drink it unless it’s been properly treated. Roof contaminants, animal droppings, and industrial pollution can all find their way into your tank.

It’s best to use rainwater for things such as watering the garden which poses little health risks.

Some measures to make the water more sanitary are to have

• First-flush diverters
• Fine mesh screens
• Sediment filters
• Clean it with sodium hypochlorite in the appropriate way

If you rely on rainwater to survive or drink, it’s important that you take appropriate measures to make sure your water is sanitary.

Different Types of Tanks

🟩 Plastic (Poly) Tanks

These are affordable, lightweight, and rust-resistant. Polyethylene tanks make up over 50% of the market. Plastic is very mouldable so can come in many sizes and shapes, including slimline styles.

However, plastics can break down over time and release microplastics. These microplastics can enter the rainwater and be harmful to humans if consumed. Try to avoid tanks older than 15 years, especially if they are worn out.

🟦 Steel Tanks

Steel tanks are quite strong and durable. However, they can rust without proper coating. With maintenance, these can last up to 10- 15 years.

🟧 Fibreglass Tanks

These are longer-lasting and more common in commercial settings. Fibreglass doesn’t rust or degrade the same way steel or plastic does. However, they can be more costly and hard to maintain underground.

⬛ Concrete Tanks

Best for underground use, concrete is super durable and can have a pretty long shelf-life. It stays cooler in summer and hides well under landscaping. Concrete is also less likely to be damaged during storms. 

However, this material is more expensive. Care also needs to be taken to avoid cracks. A plastic coating is also usually added because concrete is porous and can let water escape.

What You Can Use Tank Water For

Gardening

This is probably one of the more practical uses of rainwater. This can cut down your water bill but also has the least health risks. Especially in summer, plants need extra water because of just how hot it can get. Personally, my grandfather has been gardening all his life and uses rainwater for his plants.

Emergency Use

During a bushfire, having access to an extra supply of water can be crucial. Moreover, during periods of drought or water restriction, you can still keep up with some of your activities that need water.

Everyday Tasks

This can be a cheap way to do tasks like giving your car a bit of a wash. However, even for something like bathing, it is recommended that water is appropriately sanitised and safe for use.

Drinking (MUST BE SANITISED)

Some people rely on rainwater to drink. Whilst this is not recommended at all, if this is to be done it is imperative that the water is sanitised. Viruses, pesticides, and heavy metals can enter the tank through runoff. 

What About Rockhampton?

Rockhampton gets a decent amount of rainfall each year, which is good for a water tank. Locals have been using tanks here for over 100 years, and the community is well-versed in droughts, bushfires, and floods.

But there are local risks to be aware of:

• Flying foxes are common, and their droppings can contaminate roofs.
• The risk of viruses means any contact with bat urine or feces must be taken seriously.
• Frogs, lizards, and possum droppings can contaminate the water system.

To minimise health risks:

• Use a first-flush diverter
• Clean gutters regularly
• Use fine mesh at tank entry
• Disinfect the water tank appropriately with sodium hypochlorite or as per the guidelines.
• Never drink untreated rainwater.

Installing a rainwater tank isn’t just about saving money, although that’s a big part of it. It’s about taking control of your home’s water use, being prepared during emergencies, and doing your bit for the environment.

However, at the end of the day, this is your choice to make the most useful, safest, and cheapest decision.

And remember, if you’ve got something wrong with you’re plumbing… We’re happy to help. 

Whether it’s blocked drains, leaking taps, or smarter water usage, you deserve plumbing that works for you.