Do we need to start installing rainwater harvesting systems into commercial buildings?

After such a hot, dry summer, we’re all aware of the need to use water more efficiently. With water shortages likely to be a more frequent issue in the UK over the next few years, now is the time to take action. We talk a lot about reusing grey water as part of your business’s water efficiency strategy, but do businesses also need to start installing rainwater harvesting systems into commercial buildings?

Why bother to harvest rainwater?

Rainwater is free. There are times of the year when it’s plentiful and other drier times when it is in short supply, so it makes sense to harvest it and store it ready for dry spells. In doing so, your business could save a lot of money, with the potential of getting an ROI on your commercial rainwater harvesting system sooner than you might think. And remember that the drier the UK becomes, the more expensive water will be, so any investment you make now could pay for itself even more quickly.

By harvesting rainwater during heavy spells of rain, you are also helping to reduce the risk of localised flooding.

What can you use harvested rainwater for?

UK tap water is highly treated because it needs to be potable - drinking, bathing and food preparation all require exceptionally clean water. However, those activities don’t account for all our water usage, and this is where rainwater comes in. Rainwater is perfectly safe to use to flush toilets, water grounds and plants, clean vehicles, and wash down yards and paths. It is also OK to use rainwater to wash clothes in.

Types of commercial rainwater harvesting

With commercial rainwater harvesting, the water is collected from roofs and gutters and directed into a reservoir tank via filters which stop debris (such as twigs, leaves and also the majority of sediment) contaminating it. The water then goes into a flow-calming inlet before entering the reservoir tank so it will not disturb any sediment that may have settled in the tank. Reservoir tanks are also installed with an overflow pipe that will direct water into the ground away from your premises, thereby reducing the risk of flooding.

If the reservoir is placed underground, the water is then pumped to the toilets, other appliances and outside taps as and when needed. Alternatively, the harvested water can be pumped up to a header tank at the top of the building, then gravity will get the water from the tank to where it is needed.

If you have large premises, it is possible to utilise a number of storage tanks and link them together.

Are there any regulations with regard to rainwater harvesting?

The Environment Agency states that rainwater harvesting is an efficient way to use water. As it is not harmful to the environment, it is not regulated - unless you opt to use it in conjunction with abstraction from ground or surface water. However, you do have to comply with certain conditions including ensuring the reservoir you collect the water into only contains rainwater and not using the harvested rainwater as a clean water supply.

As a result of the UK’s shortage of reservoirs, a drive for companies to become water positive, and rises in utility bills, in the future rainwater harvesting could play a huge part in the efficient use of business water.

Interested in learning more about the services Castle Water provides? You can read about our business water services, water efficiency audits & trade effluent advice. Contact us to learn more or get an instant quote today.