Rainwater Tanks Made in Melbourne for Australian conditions

Fleximake Rainwater Bladder tanks are designed and manufactured in Australia. Our bladder tanks are self-supporting and are made of heavy duty, reinforced PVC material which is puncture resistant, allowing them be robust yet flexible. These flexible and collapsible rain water tanks are superior to the traditional, rigid tanks as they take up less space and can easily utilise areas that are unusable for other purposes such as spaces with limited height. This means that you can place it under your house or under a deck (i.e. under deck tank or under house rainwater tanks). 

You can also fit our rainwater bladder tanks in spaces that have an awkward shape that a rigid tank would not be able to fit in. Not only is it convenient and allows your rainwater collection system to be hidden, but it is also easier to install as it is flexible. We have two different fabric material options for these tanks; Potable (suitable to store drinking water as per AS/NZ 4020) and Non-Potable. Standard sizes of our rainwater tanks range from 750L to 40,000L. We can manufacture custom dimensions and shapes to perfectly fit your space and capacity requirements.

Fleximake can provide three different arrangements for connecting the downpipe to the bladder tank for harvesting rainwater; bottom fill, top fill and side fill. These provide great flexibility, allowing you to choose the method that is most suitable for your specifications.

If our standard rainwater bladder tanks do not suit your needs or if you have an inquiry, you can simply contact us and we will give you a solution to perfectly fit your requirements.

We offer three filling inlet connection configuration choices for flexible rainwater bladder tanks to perfectly fits your unique space.

Bottom Fill Configuration

Top Fill Configuration

Side Fill Configuration

Leaf Eater Original


All tank options have multiple accessories to support the installation and make it more affective. Find out about these compatible accessories by visiting the accessories page below.

Features of Fleximake Rainwater Bladder Tanks

  • Made of heavy duty, puncture resistant and reinforced PVC material
  • Flexible, but robust and durable
  • Easy to install
  • Guaranteed longevity
  • Can be made to fit any space available
  • Wide selection of standard sizes to fit your needs
  • Can be made to custom requirements
  • Easy to transport as it can be rolled into a small package and costs less to transport
  • Can be placed in areas with a height restriction and awkward shaped spaces

Features of Fleximake Rainwater Bladder Tanks

Traditionally the method for storing rainwater has been hard corrugated iron or poly tanks. These tanks take up a lot of usable space that could be used for other endeavours. As homes become larger and block sizes become increasingly smaller, a rainwater storage solution is needed for both space and aesthetic conscious home owners who desire to save money. Rainwater bladders are flexible tanks that are not rigid, allowing them to fit into spaces that would not usually be used to store water. For example, underneath the house or as an underdeck water tank. There are some flat rainwater tanks available in the market, however, the flexible nature of the bladders makes them superior compared to other types of low profile rainwater tanks.

Bladders tanks enable you achieving a low cost rainwater harvesting solution. Unlike rigid rainwater tanks, our flexible rainwater bladder tanks are easy and cost much less to transport especially to rural areas. As you can imagine, only a few rigid poly tanks can fit into a large truck at once, causing it to be very expensive to transport. On the other hand, a large bladder tank, such as one with a capacity of 20,000L, can be rolled up into a small package of 60cm x 50cm x 50cm for transporting. This makes bladders an ideal solution for rural rainwater tanks application.

Once the bladder tank arrives at its destination, it is easy to install as you do not have to push a large container as you would for a rigid rainwater tank. Due to its flexibility, rainwater bladder tanks can accept much greater installation dimension tolerances compared to a rigid water tank, saving installation time. Rainwater is a valuable natural resource that has been collected by Australians for domestic, agricultural and commercial use since colonial times. With Fleximake flexible rainwater bladder tanks, storing water is less space consuming and gives opportunities for rain collection to every Australian.

Rainwater Bladder Tank Sizes

At Fleximake, we have a range of standard sizes with capacities from 800L small rainwater tanks to 40,000L large rainwater tanks. The table below shows the dimensions for each size.Please visit fmestore for Fleximake standard rainwater tanks prices. These can be used as residential rainwater tanks and also for commercial water storage application. Up to tank capacity of 10,000L are commonly used as under deck rainwater tanks in houses.

Model No.Width (m)Length (m)Height (m)Capacity (L)
RWP-010-0301 m3 m0.45 m800 L
RWP-010-0401 m4 m0.45 m1,100 L
RWP-010-0501 m5 m0.45 m1,400 L
RWP-010-0601 m6 m0.45 m1,650 L
RWP-010-0801 m8 m0.45 m2,250 L
RWP-010-1001 m10 m0.45 m2,850 L
RWP-015-0301.5 m3 m0.7 m1,650 L
RWP-015-0401.5 m4 m0.7 m2,300 L
RWP-015-0501.5m5 m0.7 m3,000 L
RWP-015-0601.5 m6 m0.7 m3,700 L
RWP-015-0801.5 m8 m0.7 m5,000 L
RWP-015-1001.5 m10 m0.7 m6,400 L
RWP-020-0302 m3 m0.75 m2,550 L
RWP-020-0402 m4 m0.75 m3,650 L
RWP-020-0502 m5 m0.75 m4,700 L
RWP-020-0602 m6 m0.75 m5,750 L
RWP-020-0802 m8 m0.75 m8,000 L
RWP-020-1002 m10 m0.75 m10,000 L
RWP-030-1003 m10 m1 m20,000 L
RWP-040-1004 m10 m1 m30,000 L
RWP-050-1005 m10 m1.1 m40,000 L

Fleximake can provide you a tailor made, custom rainwater tank solution to perfectly fit your requirements. We can design and manufacture rain water bladder tanks to exactly match your need in regard to the size. We can also manufacture very large bladders for large scale rainwater harvesting system. The friendly team at Fleximake are always happy to help in regards to any specific requirements. Please simply fill the Enquire form below or give us a call on 1300 195 295. We’ll discuss your needs, rainwater tank sizing and deliver the perfect solutions to you on time. We can help you to achieve successful DIY rainwater collection system.

How to choose a size for your rainwater bladder tank

When deciding on a rainwater tank, it may be tricky to estimate the water storage size as we cannot exactly predict how often it will rain. However, you should consider the past rainfall data for your area, water usage and space availability.

The amount of water you can collect mostly depends on the amount of rainfall in your area, for example it would rain more in coastal areas compared to areas isolated from water. The Bureau of Meteorology (BOM) publishes past monthly rainfall data for your area in the website, Table Format. BOM also publishes this data in a Map Format.

Once you have found your rainfall data, you can then find out the volume of water that you could collect, by multiplying the amount of rainfall with your roof area. If you do not know the roof area, you can find it by looking at the building plans or going online to google maps. This is important so that you can know a rough number on how much water you could collect every month.

You may also need to consider the climate patterns and irregularities in your area. If your area is prone to spontaneous heavy rains or dry seasons, then it is best to get a larger tank to keep the water for more necessary times. It is also important to estimate your water usage prior to deciding the size of your rainwater tank. This helps you to avoid choosing an unnecessarily large tank or a tank that is too small. Lastly, you need to consider how much space is available for you to place your rainwater tank. Fleximake rainwater bladder tanks and under deck water tanks can utilise unusable place, allowing them to be space efficient. Once all of these have been considered, you can decide the most suitable size for your rain harvesting tank that collects sufficient water for the best price.

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