Best Rainwater Tanks Options for Small and Large Properties

Rainwater harvesting has become increasingly popular across Australia, and for good reason. With unpredictable weather patterns and growing concerns about water security, more homeowners are turning to rainwater tanks as a practical solution. Whether you're living on a compact suburban block or managing a sprawling rural property, there's a tank option that'll suit your needs perfectly.

In this guide, we'll explore everything you need to know about choosing the right rainwater tanks for your property. From understanding your storage requirements to comparing different tank types and materials, you'll walk away with all the knowledge needed to make a confident decision. Plus, we'll cover maintenance tips, installation considerations, and even touch on whether you can safely drink rainwater from your tank. Let's get stuck into it!

Understanding Your Rainwater Storage Needs

Before you start shopping for a rainwater tanks, it's essential to figure out exactly what you need. Getting this right from the start will save you money and ensure you're making the most of every drop that falls on your roof.

Assessing Your Property Size and Water Requirements

Your property size plays a huge role in determining the right tank for you. A small courtyard home in Sydney will have vastly different needs compared to a five-acre block in regional Victoria. Think about what you'll actually use the water for garden irrigation, toilet flushing, laundry, or perhaps even drinking water.

How Much Rainwater Can You Collect from Your Roof?

Here's a handy formula: for every square metre of roof area, you can collect roughly one litre of water per millimetre of rainfall. So if you've got a 150m² roof and receive 600mm of annual rainfall, you could potentially harvest around 90,000 litres yearly. That's quite impressive!

What Size Rainwater Tanks Do I Need for My Property?

This is probably the most common question homeowners ask, and the answer depends on several factors working together.

Small Property Recommendations (Under 500m²)

For compact blocks, space is your biggest constraint. Slimline tanks ranging from 1,000 to 3,000 litres work brilliantly in tight spaces. They can tuck neatly against walls or fences without dominating your outdoor area.

If you're mainly using rainwater for garden irrigation and the occasional car wash, a 2,000-litre tank should serve you well. However, if you're planning to connect to toilets and laundry, consider bumping up to 5,000 litres or installing multiple smaller tanks.

Large Property and Rural Recommendations

Bigger properties can accommodate larger rainwater tanks, and frankly, they should. Rural homes often rely more heavily on tank water, especially if mains connection isn't available. Tanks ranging from 10,000 to 50,000 litres are common on larger blocks.

Best Rainwater Tanks Types for Different Properties

Not all tanks are created equal, and choosing the right style can make all the difference to both functionality and aesthetics.

Slimline Tanks: Perfect for Tight Spaces

Slimline tanks are the heroes of suburban backyards. Their narrow profile typically under 700mm wide means they fit comfortably beside houses, along fences, or in narrow side passages. They're available in capacities from 400 to 5,000 litres.

These tanks often come in a range of colours to complement your home's exterior. Installation is straightforward, and many homeowners manage it themselves with minimal fuss.

Round Tanks: Maximum Capacity for Larger Blocks

Round tanks remain the most popular choice for good reason. Their design is structurally efficient, meaning you get more storage capacity for your dollar. They're available in sizes from small 500-litre options right up to massive 50,000-litre models.

The main consideration with round tanks is space. You'll need adequate clearance around the tank for installation and maintenance access. They work best on larger properties where visual impact isn't a primary concern.

Underground and Modular Options

Underground tanks are fantastic when you want storage without sacrificing garden space. They're installed beneath driveways, lawns, or paved areas, keeping everything hidden from view. The trade-off is higher installation costs and more complex maintenance access.

Modular tank systems offer remarkable flexibility. You can start with a smaller capacity and add modules as needed. Bladder tanks fit beautifully under decks or in crawl spaces, making use of otherwise wasted areas.

What Are the Best Materials for Rainwater Tanks?

The material you choose affects durability, cost, water quality, and installation requirements. Here's what you need to know about each option.

Polyethylene (Poly) Tanks

Poly tanks dominate the Australian market, and it's easy to see why. They're lightweight, affordable, and resistant to rust and corrosion. Most come with warranties of 20 years or more, offering excellent value.

These tanks won't affect water taste and require minimal maintenance. The main downside is UV degradation over time, though quality manufacturers use UV-stabilised materials to combat this.

Steel and Concrete Alternatives

Steel tanks offer exceptional durability and can last 30 years or longer with proper care. They're available in corrugated or flat panel designs, with options for different coatings including Colorbond. Steel tanks are ideal for larger capacities and rural properties.

Concrete tanks are the heavyweight champions literally. They're incredibly durable and naturally cool the water inside, reducing algae growth. However, installation requires heavy machinery, and they're significantly more expensive upfront.

Maintenance and Water Quality

Keeping your tank in good condition ensures clean water and extends its lifespan considerably.

Regular Cleaning and Inspection Tips

Inspect your tank every six months, checking for debris, cracks, or signs of contamination. Clean gutters and inlet filters regularly blocked filters reduce collection efficiency dramatically.

Most rainwater tanks benefit from professional cleaning every two to three years. This involves removing sediment from the tank floor and checking internal components.

Can You Drink Rainwater from a Tank?

With proper precautions, yes! Australian guidelines support drinking properly collected and maintained rainwater. Install appropriate filtration typically a sediment filter followed by UV sterilisation for drinking water applications.

Keep your roof clean, install first-flush diverters, and maintain your system regularly. If you're concerned, have your water tested periodically for peace of mind.

Installation Considerations

Getting installation right is crucial for optimal performance and compliance with local regulations.

DIY vs Professional Installation

Smaller slimline tanks can often be installed DIY, saving several hundred dollars. However, larger tanks and plumbed connections generally require professional assistance. Incorrect installation can void warranties and create safety hazards.

Always check council regulations before proceeding. Some areas require permits for tanks above certain sizes, while others have specific placement requirements. Getting this sorted beforehand avoids headaches later.

Finding Your Perfect Rainwater Tanks

Choosing the right rainwater tanks doesn't need to be overwhelming. By understanding your property's requirements, comparing tank types and materials, and considering long-term maintenance needs, you're well-equipped to make a smart decision.  

Remember, the best rainwater tanks is one that matches your specific situation your property size, budget, intended use, and aesthetic preferences all matter. Don't rush the decision. Take time to get quotes from reputable suppliers and ask plenty of questions.