Rainwater harvesting is the collection and storage of rain which falls onto the roof of a property. If you are considering using rainwater harvesting to supplement your mains water supply, James Shenton – General Manager at rainwater harvesting tank manufacturer Tuffa Tanks – shares his top tips.
Clean out your gutters
A good place to start is the gutter. Make sure these are clear and free from leaves or debris which might impede the flow of rain from the roof to the downspout. To help ensure this, flush out your downspouts with water to remove any blockages on the angles. Next, you might have to install additional pipework or a rainwater diverter to channel the water from the downspout to your rainwater storage. Although this sounds like a costly investment, a diverter sometimes comes with a purpose-built tank.
Do you choose to store water above or below ground?
You’ll need to consider whether you want an above-ground tank near to your property or below-ground water storage. There are pros and cons to both but, generally, an above-ground tank will be easier to use and access for inspections and maintenance while the below-ground tank is more expensive to install, requiring excavation and additional pipework.
Invest in a good quality system
You get what you pay for. Select a tank from a renowned manufacturer with a good track record in providing reliable and, if possible, purpose-built systems.
When shopping around, you want to look for tanks which at least have large capacities as well as filtration and pump options to give a regular, pressurised water supply.
However, we would also recommend systems which are manufactured from recyclable polythene, require limited maintenance, corrosion resistant and UV stabilised.
On the subject of capacity
The average water butt will hold between 100 to 300 litres. Although this sounds good enough, you might actually need more – depending on your requirements. During wetter periods, there is every likelihood that the tank will overflow. In urban areas, this may cause localised surface water that is not easily diverted to a drain or natural watercourse, leading to temporary flooding of pathways or gardens and making you really popular with your neighbours!
Watch out for foreign objects
Rainwater harvesting is not without its hazards and your system should be inspected regularly to ensure foreign objects don’t negatively affect the quality of water. To begin with, install a leaf filter to prevent nozzles and sprayers from becoming blocked. Next, ensure your tank is correctly sealed and – if your system has one – only examined through a dedicated inspection hatch.
Use rainwater to keep your garden looking great
From the outset, you should consider how you want to use your harvested rain. With good filtration, rainwater is perfect for the garden – the lack of chemicals (such as chlorine) give the rainwater a neutral pH balance which is better for irrigation and plants than mains water.
Not only that, but it’s also much cheaper. According to Anglian Water, an average hosepipe uses between 550 to 1000 litres of water per hour. Therefore, whether you are watering the garden or washing the car, using water from a purpose-built rainwater harvesting tank will lead to significant savings on your water bills.
Can rainwater supplement your mains water supply?
Rainwater can also supplement your mains water supply inside the house. For example, the Energy Saving Trust estimates that flushing the toilet and using your washing machine accounts for about 33% of average household water use in the UK. A rainwater harvesting tank can easily be retrofitted to your property, but if you want to supplement your mains water usage in this way, you will need a qualified plumber to install and fit the pipework into your property. You can find one through the Association of Plumbing & Heating Contractors or via WaterSafe.
Regardless, if successful, you could be saving quite a bit on your water bills.
Reap the rewards from rainwater harvesting
Water is a precious natural resource that we take for granted in the UK. Rainwater harvesting offers an affordable and sustainable alternative supply to mains water. A quality tank is relatively inexpensive and, once installed, will provide regular free water throughout the year for many years.