Available Colours
Available Colours
* Product May Vary Slightly. Polymaster will not be held liable for incorrect colour impressions, request your Polymaster colour sample to view colours. Polymaster tank colours represented match COLORBOND steel colours. *COLORBOND® and colour names are registered trademarks of Blue Scope Steel Ltd™.
RWT31700
31,700L Round Water Tank
This popular large 31,700ltr (7,000 gallons) rainwater tank is well suited to rural properties or large town blocks where you require plenty of water storage especially in combination with a second tank when rainwater is your main supply for household use. This certified rainwater tank is manufactured with strength in mind. It also allows you to collect rainwater and be prepared for times of low rainfall.
When you invest in a rainwater tank it’s important that you get one that lasts and is fit for purpose. Australian standards are put in-place to give households, peace of mind when it comes a tanks’ usability.
- No joins, no seams — one-piece moulded with a self-supporting roof that won’t sag.
- Safe for drinking water — food-grade, BPA free, certified to AS/NZS 4766.
- Big capacity, one footprint — 31,700L in a single tank, with a 40mm outlet for strong flow.
Get in touch
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Dimensions
Capacity:
31,700L (7,000 gallons)
Inlet Height:
1,610mm
Diameter:
4,100mm
Overall Height:
3,040mm
All measurements listed are approximate only
Standard Fit Out
Strainer Position:
12 o’clock
Overflow Position:
11:30 o'clock
Outlet size:
40mm (Brass)
Outlet Position:
6 o’clock
Strainer Size:
400mm
Ball Valve:
40mm
Guides & Specifications
Installation Manual
Water Tank Category Brochure
When you invest in a rainwater tank it’s important that you get one that lasts and is fit for purpose.
Australian standards are put in-place to give households, peace of mind when it comes a tanks’ usability.
EXPERT SOLUTIONS
What makes Polymaster tanks the toughest?
- Self-supporting roof design means no support poles are necessary
- Extra thick walls for maximum strength
- Double strength UV+ resin ensures ultimate protection against the harsh sun
- One-piece construction with no joins, seams or part-lines
PRODUCT FEATURES
Highest Quality & Standards
Every tank is built to strict Australian standards, with quality fittings and components ensuring lasting performance and dependable, everyday water storage.
Ball Valve
Controls water flow at the outlet, letting you open or shut off supply quickly and reliably whenever it’s needed.
Brass Outlet
A durable, corrosion-resistant outlet fitting that connects to your plumbing or hose for reliable, long-term water access.
Lifting Lugs
Moulded into the tank for safer, easier handling during delivery and installation, without extra equipment.
Strainer
Filters debris and leaves from incoming water before it enters the tank, keeping stored water cleaner.
Overflow
Directs excess water safely away from the tank once it’s full, protecting the base and surrounding site.
Gallery
Explore Our Water Tank Gallery
See the 31,700L round water tank in real-world settings, from rural properties to rooftop and aerial views, showcasing its size, build quality, and Colorbond® finish across a range of installations.
FAQs
Frequently Asked Questions
Got questions about the 31,700L round water tank? Here are answers to some of the most common questions about durability, safety, and performance to help you choose with confidence.
Are round rainwater tanks and components weatherproof?
Yes — Polymaster rainwater tanks are fully UV resistant and built for Australian weather conditions. Components are carefully selected to ensure they’re protected and resistant to the elements.
When would I choose the 31,700L over the 50,000L Mega Tank?
The 31,700L offers a smaller footprint (4.1m diameter vs 4.6m) while still delivering serious capacity, making it a good fit where site space is limited but you still need large-scale storage.
What do your round water tanks weigh?
Weight varies with tank size and the number of fittings, but our round water tanks are comparable in weight to fibreglass or galvanised alternatives.
Is the smooth wall poly tank weaker than corrugated poly tanks?
This is a common myth. Wall strength comes down to material thickness and type, not the corrugated or smooth finish. Both designs offer similar strength — it’s a matter of aesthetics rather than durability.
What makes Polymaster worth it over cheaper alternatives?
One-piece rotomoulded construction means no seams to fail, and UV+ double-strength resin protects against cracking and fading. It’s built to hold its shape over time, rather than developing the visible sagging some cheaper tanks show with age.
Are round rainwater tanks and components weatherproof?
Yes — Polymaster rainwater tanks are fully UV resistant and built for Australian weather conditions. Components are carefully selected to ensure they’re protected and resistant to the elements.
When would I choose the 31,700L over the 50,000L Mega Tank?
The 31,700L offers a smaller footprint (4.1m diameter vs 4.6m) while still delivering serious capacity, making it a good fit where site space is limited but you still need large-scale storage.
What do your round water tanks weigh?
Weight varies with tank size and the number of fittings, but our round water tanks are comparable in weight to fibreglass or galvanised alternatives.
Is the smooth wall poly tank weaker than corrugated poly tanks?
This is a common myth. Wall strength comes down to material thickness and type, not the corrugated or smooth finish. Both designs offer similar strength — it’s a matter of aesthetics rather than durability.
What makes Polymaster worth it over cheaper alternatives?
One-piece rotomoulded construction means no seams to fail, and UV+ double-strength resin protects against cracking and fading. It’s built to hold its shape over time, rather than developing the visible sagging some cheaper tanks show with age.