How to Choose and Install a Rainwater Tank – The Key Steps
Installing a rainwater tank is a fantastic way to reduce your water consumption and save on bills, For households on rural properties its their main supply. The tank selection and installation process involves two key elements:
- Positioning and Installing the Tank
- Plumbing Connections – Inlet, Outlet, and Overflow.
Step 1: Positioning and Installing the Tank
Choosing the right location for your tank is critical to ensure optimal water collection and ease of use. Even as part of this first step, engaging with a Licensed Plumber to provide assistance is recommended, they can provide an onsite consultation and look at the layout of existing downpipes/gutters and plumbing pipework to provide feedback as to which of the possible locations around your property would be most suitable in that respect.
Once the most suitable location is identified, the space available can then be established.
Measuring the space. The width, length and height of the space available (measured in millimetres) are all important.
We can then look at the tanks available and recommended options
We can offer the supply and delivery of the following types of Rainwater tanks:
Underground poly rainwater tanks
Slimline and modline steel rainwater tanks
Once you’ve picked the right tank size and type, you need to find a flat, stable area for installation. Here are some key considerations:
Flat, Stable and Prepared base: The base must be solid enough to support the full weight of the tank when it’s filled with water. Poly tanks can be sighted on either a compacted Crusher dust base or a reinforced concrete slab. Steel tanks require a concrete slab.
Guides for steel and poly base prep can be found in the links below:
Proximity to Downpipes: Place your tank close to the building’s downpipes so you can easily connect them for rainwater harvesting. Shorter piping distances simplify the installation process and can reduce installation costs.
Maintenance Access: Make sure there’s enough space around the tank for future maintenance and cleaning.at a minimum 100mm is required in any given direction, not accounting for fittings and other plumbing connections.
Step 2: Plumbing Connections
The plumbing setup is also a key element, there are several considerations, including rainwater flow from the roof into the tank, distributing rainwater from the tank to other parts of the house or garden, and managing overflow:
- Connecting the Roof to the Tank Inlet
Gutter and Downpipe System: Your rainwater is collected from the roof and directed to the tank via gutters and downpipes. A well-maintained gutter system ensures the maximum catchment of clean water. Gutter Guard, Rainheads and first flush diverters are all important accessories that can help minimise any debris that may be washed off/from the roof. A first flush diverter can prevent the initial flow of dirty rainwater (containing dust, leaves, or pollutants) from entering your tank, allowing only cleaner water to fill the tank.
- Outlet Connection – Water Usage from the Tank
Pump Systems: If you’re using the tank water for household use (toilets, washing machines, etc.), you’ll need a pump to distribute the water. We have a comprehensive selection of pressure pumps available in different output capacity and use types.
If mains water is available onsite, regulations mandate the use of mains water for anything that may involve human consumption (including showering etc), however it can be used for Toilet flushing and laundry use, particular pump systems can be supplied with “switch over valves” that enable the transition of supply from rainwater to mains should the tank be empty, it is critical that sanitation services in a household are maintained at all times, even if the tank is empty. If mains water is not available to the property, typically a rural or acreage property, then this does not apply.
Post tank Filtration System: For households purely reliant on non-mains water supply. If the water will be used for human consumption, installing a filtration system is highly recommended to ensure the water is clean and safe for use. We offer a number of options in this regard, we supply and recommend the Puretec range of filtration products , The G7 Filter system is a great comprehensive system suitable for most applications.
- Overflow System
Overflow to a Stormwater service or Rubble Pit: Rainwater tanks have an overflow fitting to handle excess water when the tank is full. This overflow needs to be directed away from the house and/or tanks foundations. The best practice approach is having the overflow plumbed into the stormwater service available with most urban properties ,or if a rural property, a rubble pit.
Bonus tip: Most Tank types and sizes have optional positions where fittings might be placed during tank construction. For example, having the overflow already pointed toward the stormwater service may simplfy pipework, reduce installation cost and provide a neater finish to the overall project.
Example Diagram for Poly Round tanks:
Example Diagram for Poly Slimline tanks: 
In Summary:
When installing a rainwater tank, make sure you take the time to prepare a stable base. Additionally properly routing water pipework from your roof into the tank, setting up a reliable pump and filtration system, and handling overflow with a stormwater service or rubble pit ensures your tank functions efficiently and lasts for many years. Engaging a Licensed Plumber to provide assistance is recommended