Rain Barrel Comparison to Large Rainwater Tanks

If you're living in the Inner West or nearby areas like Kogarah or St. George, you've probably noticed how quickly water bills can rise—especially in dry spells. That’s why more homeowners are looking into rainwater harvesting as a smart, sustainable solution. Whether you're trying to keep your garden green year-round or want a backup water supply, performing a rain barrel comparison and installing a rainwater system is a solid move.

Now, when it comes to choosing between a rain barrel and a large rainwater tank, it’s not just about size. It’s about what works best for your property, your goals, and yes—your plumbing setup too. Let’s break it down.

What Are Rain Barrels?

Rain barrels are the go-to for small households or anyone new to water conservation. They're typically 190 to 340 litres (that’s around 50 to 90 gallons) and designed to sit snugly under a downspout. These are perfect for watering your garden or washing the car—nothing too full-on.

They usually come with:

1. Mesh screens to keep mozzies and debris out

2. Overflow valves for excess water

3. Simple installation you can handle in an afternoon

A homeowner in St. George once asked us if a single rain barrel could water her veggie garden. We installed a 340L model under her garage roof, and after one decent rainfall, it filled up completely. She was able to hand-water her patch for days—and loved the savings.

What Are Large Rainwater Tanks?

On the other end, large rainwater tanks—sometimes called cisterns—offer storage starting from 750 litres and can go beyond 11,000 litres (200 to 3,000+ gallons). These are the heavy-duty option. They can be above or below ground and are often connected directly to your irrigation or household plumbing systems (non-potable, of course).

They’re best for:

1. Keeping a large garden alive during water restrictions

2. Supporting toilet flushing and laundry use

3. Getting drought-ready in areas prone to dry seasons, like parts of Sutherland Shire

You’ll want to think about permits and professional installation with these. But the payoff? You’ve got a serious backup water supply.

Key Differences: Rain Barrels vs. Large Rainwater Tanks

Rain Barrels: Pros and Cons

Pros

1. Affordable, especially if you’re just starting out

2. Easy to install yourself

3. Portable—great if you rent or plan to move

Cons

1. Small storage fills up fast

2. Won’t cut it if you’re planning to run sprinklers or connect to plumbing

3. Needs regular emptying or use to avoid overflow

Pro-Tip: If your roof has multiple downpipes, install a barrel under each one and link them with connectors. This boosts your capacity without taking up too much space.

Large Rainwater Tanks: Pros and Cons

Pros

1. Can supply a household or keep a big lawn green

2. Handles heavy rainfall without constant overflow

3. More efficient for homes with large roof areas

Cons

1. Costs more upfront

2. Takes up space and often needs professional installation

3. Maintenance is more involved

Pro-Tip: Install a first flush diverter to keep the initial dirty runoff out of your tank. It’ll save you a lot of cleaning and improve water quality.

Choosing What’s Right for You

Here’s how we usually help customers in the Inner West decide:

Space

Got a small backyard or limited access? A rain barrel is probably your best bet.

Water Needs

If you’re only watering a herb garden, you don’t need a 3,000L tank. But if you want to feed toilets, washing machines, or irrigation systems, go bigger.

Budget

Rain barrels are great for tight budgets. Large tanks cost more but offer better long-term value.

Regulations

Some councils in NSW have specific rules about tank sizes and installations. We’ll help you navigate that.

One of our regular clients in Kogarah initially went with a rain barrel but found herself refilling watering cans multiple times a day. We upgraded her to a 2,000L slimline tank with a pump after doing rain barrel comparison, and she hasn’t looked back since.

FAQs About Rain Barrel Comparison

What is a good size for a rain barrel?

Stick to 190–340L if you’re starting out. That size fills up fast with one storm and is easy to manage.

Are collapsible rain barrels worth it?

They work great for small patios or rental properties but aren’t as tough or long-lasting.

How do you keep rain barrels from stagnating?

Use mesh screens, keep them shaded, and empty them regularly. We also recommend mosquito dunks or a dash of cooking oil to stop bugs.

How many rain barrels do I need?

Divide your roof area by 9.3m² (about 100sqft). One 60-gallon (around 227L) barrel per section works well. You can always connect more in a series.

What is the best colour for a rain barrel?

Stick to blue, green, or brown. These block UV light better than white or clear barrels, which can get slimy quick.

What if I want to know more about rain barrel comparison?

If you're still on the fence about which system to go with, you're not alone. Each property is different, and what works for your neighbour might not work for you. We’re happy to give tailored advice on rainwater harvesting—whether you want to start small or go all in with a large setup. From the Inner West to Sutherland Shire and all around NSW, we’re here to help you make a smart, water-wise decision.

At All Needs Plumbing, we offer a $0 callout fee, 24/7 same-day service, and a 15% discount for seniors. Thinking of upgrading your hot water setup while you're at it? You’ll get $150 off hot water systems when you book with us. 

Let’s sort your rainwater collection system the right way—from sizing and selection to installation and maintenance.

Ready to get started? Contact us today and let’s talk rainwater solutions that work for your home.

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