Rainwater Harvesting for the Garden and Home a Guide

Building a Garden Rainwater Harvesting System

With summers getting hotter and the threat of hosepipe bans becoming more of a way of life here in the UK, there’s no wonder more people are looking for ways to capture rainwater for the garden.

But where do you start? If you’re not familiar with the rainwater harvesting process then it may feel a little daunting to begin with, so we’ve put together this simple guide, to take away some of the mystery and show you how easy it is to install a rainwater catchment system for gardens and homes.

So how do you go about harvesting rainwater?

Rainwater is typically collected from a roof and fed by a downpipe (drainpipe) into a water storage tank. During this stage, it’s important to filter the water coming into the tank, so that as much debris (e.g. leaves, twigs etc. carried in the water) are removed, to help prevent the water from going sour in the tank.

Once in the rainwater storage tank, the harvested water can be used for a variety of *non-potable (non-drinking water) purposes, from simple garden watering and/or cleaning the car, to supplying water for toilets, washing machines and so on.

Simply put, that’s all there is to it! However….

…there are of course many variations to this simple process , such as the amount of water being stored, where the water storage tank is situated (e.g. this can be above ground or, for larger installations, often below ground); as well as extra elements that can be added to the system, such as a pump to provide more pressure to move the water from the tank to your desired location(s); or adding a mains water top-up to the stored water tank, to automatically top-up the tank if the water level falls below a minimum level (this is particularly useful, for example, in situations where the set-up depends solely on water supplied from the tank to flush toilets).

Here are 3 examples of different sized Garden Water Harvesting installations, to give you an idea of how they can work…

Small Installation – Rainwater harvesting system for garden watering, using a decorative Water Butt and downpipe diverter with filter.

This simple set up enables you to collect water from the roof of your property, filter and store the water in a slimline water butt and utilise the water either from a hosepipe or watering can.

The Noblesse Water Butt is from our range of Decorative Water Butts. We have a number of different designs with varying capacities, to suit all types of available space and the desired volumes of water you may like to store.

A Medium Sized Installation – Collecting rainwater for garden watering, car washing etc. using a 3P Filter Diverter, 800 Litre Wall Tanks and an external SteelPump for extra pressure.

These slimline 800L Wall Tanks hold a lot of water considering their small footprint of just 60cm x 80cm. Super versatile, they can be used as a single 800L tank, or connected together to store a larger capacity of water. Available as a single tank or as part of our Rainwater Harvesting Kit which allows you to select your desired components (including optional pump) for a more bespoke set-up.

For a similar set up to the Rainwater Harvesting Kit but with larger tanks, our 1500L Above Ground RWH System provides an even greater capacity of water storage along with the additional option of locating the pump inside the tank if preferred.

A Larger (Underground) Installation – using the 3P Rainwater Harvesting Filters and pump to supply water for garden watering, toilet flushing, clothes washing etc.

The above illustration shows various elements which can be used in a larger RWH installation. The Rainus Filter can feed directly into the tank without the VF1 and vice versa, depending on the size of the roof. The VF1, Calmed Inlet and Uno Overflow Siphon are available separately or as one of the several Rainwater Tank Filter System Kits we have available.

For further information on any of the products mentioned in this article or if you would like help choosing products for your own Garden Rainwater Harvesting System, please contact us.

*Note: whilst some of the products in this article can be used as part of a potable (drinking water) rainwater harvesting set-up, there are additional elements (for example UV Filtration) which are not covered in this article. You should therefore refer to a specialist in this field, for further information about harvesting rainwater for drinking water purposes.