loader image
Rainwater Harvesting

Rainwater Harvesting

What is Rainwater Harvesting?

As a definition, rainwater harvesting is the capturing, filtering and storing of rainwater from the roof of a building, for reuse. However, it is more than just this. Rainwater harvesting is a method of ecological and sustainable rainwater management. The storing and reuse of harvested rainwater is an increasingly important alternative to the customary centralised drainage of rainwater.

On-site collection and use of rainwater covers a variety of applications including:

  • toilet flushing
  • laundry
  • irrigation
  • climate control of buildings
  • cleaning

and more, at private and rented properties, residential areas, community developments, industrial sites, hotels, streets, parks, golf courses, theme parks, car parks, stadia, etc.

Rainwater Harvesting

There are many different types of rainwater harvesting system, designed to meet the different uses for the collected and stored water:

  1. Water collected in storage tank(s) and pumped directly to the points of use. These are most suited to reuse that requires a pressurised water supply. This includes spray irrigation systems, vehicle washing systems, washing machines etc.
  2. Water collected in storage tank(s) and fed by gravity to the points of use. These are most suited to small water butts, with a tap at the base. In rare cases, they can be very effective in properties with high eaves, or roof plant-rooms where the main collection area sits above the plant area. In these cases the whole system can be fully gravity fed.
  3. Water collected in storage tank(s), pumped to an elevated cistern and fed by gravity to the points of use. These are most suited to supply critical points of use i.e. WC flushing. The reason for this is that, as a WRAS fluid category 5 liquid, any mains top-up must be accompanied by a type AA or Type AB air gap. In the event of a power outage, any pumped systems will fail. However a gravity fed system will continue to provide water, and top-up with mains water via a mechanical ball valve, offering a robust supply of water.

How do you collect rainwater in the UK?

Rainwater is harvested from roofs (via guttering) or hardstandings and contained in a tank, either above ground or below ground.

Hard roof surfaces are considered the most suitable for rainwater collection. Guttering and pipework should allow the water to freeflow from the collection surface to the storage tank by gravity or siphonic action. Before entering the tank, the water is filtered to separate any debris such as leaves and moss from the water. If possible, it is recommended to avoid collection from green roofs, and from trafficked areas. This is because green roofs can discolour the rainwater yellow through nutrient leaching.  Trafficked areas also require the addition of a hydrocarbon interceptor to remove fuels and oils form the rainwater prior to use.

Systems and treated water should conform to the British Standards. The most common standard used is the British Standard BS8515:2009, however this was superseded in 2018 by the new standard BS EN16941-1:2018. All systems should conform to this standard.

Water that conforms to Table NA.3 of BS EN16941-1:2018 (below) will provide water suitable for WC flushing, laundry and garden watering in most residential commercial and industrial situations. Additional equipment such as a UV (ultraviolet) light or chemical disinfectants can be used to further sterilise the water.

Rainwater Harvesting

Is rainwater harvesting legal in the UK?

Yes, it is perfectly legal to harvest rainwater that falls onto your property in the UK. In fact it is often encouraged. As the demand on water increases due to an increased population and erratic, less predictable weather conditions, harvesting your rainwater which would otherwise soak away, will reduce the demand on your mains water supply, and help to attenuate surface run-off aiding in the prevention of localised flooding. It will therefore save you money on your water bill and also reduce your carbon footprint.

It should be noted that if you live in an apartment or terraced property you may need to ask permission of the free-holder, or neighbour if the roof and downpipes are shared. However, this is often just a formality!

Finally, there are also British Standards and other regulations, such as building regulations, that must be followed so be sure to check these before installing a system.

What are the benefits or rainwater harvesting?

There are lots of reasons to harvest your own rainwater. A few are listed below:

  • Less calcium build-up in domestic appliances such as washing machines
  • Less demand on mains water
  • Cheaper water bills
  • Makes your home more sustainable
  • Attenuation of surface run-off (Sustainable Urban Drainage Systems)
  • Improved self-sufficiency, and carbon footprint reduction.

Is rainwater harvesting worth it?

Absolutely! If you choose to invest in a rainwater harvesting system, you will be futureproofing your home against water shortages, water price increases and will be reducing your carbon footprint.

Rainwater is considerably better for watering your plants and the general health of your garden than mains water because it doesn’t include the chemicals that are used to treat the mains supply.

If used for laundry, you may find you won’t need to use as much softener and your washing machine will likely last longer because it won’t get clogged with limescale.

Rainwater Harvesting

What are the best rainwater harvesting systems in the UK? We’re glad you asked!

Here at Aquaco, we are at the forefront of research and development of water recycling technologies.

We have an in-house team of engineers who are driving the industry forward by constantly designing and testing new processes, materials and technology in order to provide the most efficient, cost effective solution for your home or business.

If you’re thinking about investing in a Rainwater Harvesting system, then please fill out the ‘Get a Quote‘ form, and one of the team will contact you with further information. Otherwise, you can call us on 01622870200.

Rainwater Harvesting

Water abstraction reservoir

Water Abstraction

What is water abstraction?

The Environment Agency defines water abstraction to be ‘the removal of water resources, permanently or temporarily, from rivers, lakes, canals, reservoirs or from underground strata’. Underground strata includes groundwater from boreholes or wells. 

Impound (store) water

The Environment Agency defines a water impoundment as ‘a structure within inland waters that can permanently or temporarily change the water level or flow’. This includes:

  • dams
  • weirs
  • fish passes
  • hydropower turbines
  • sluices
  • penstocks
  • culverts
  • lock gates
  • retaining walls
  • flumes
  • reservoir embankments
  • temporary diversions during construction work


You must have an impoundment licence before you start work on an impoundment structure

Water abstraction vs extraction

You may be wondering why it’s not called water extraction. The only difference between extraction and abstraction is that ‘abstraction is the act of abstracting, separating, withdrawing, or taking away i.e. the state of being taken away, while extraction is an act of extracting or the condition of being extracted.

The basic principle is that abstraction is the process of withdrawing the water, and extracting is the transportation of it once it has been abstracted. 

Discharge water

Discharge water is mostly considered to be liquid effluent or wastewater that has been released into surface waters or into/on the ground. 

Wastewater includes poisonous, noxious, or polluting matter/substances, waste matter, and/or trade or sewage effluent. 

You may need an environmental permit if you discharge liquid effluent or wastewater. 

It is regulated to ensure the quality of the water that is being returned, to control the volume of water that is being returned and to prevent contamination and pollution.

Water abstraction licence

The UK is already experiencing erratic weather, often resulting in extensive flooding but also droughts and water scarcity.

The effect that climate change will have and is indeed already having on water in the UK and the rest of the planet is significant, so it is vital that water is conserved wherever possible, hence the need for new legislation.

 The Government plans ‘to address unsustainable abstraction’ and ‘improve access to water by introducing more flexible conditions that support water storage, water trading and efficient use’. 

If a business abstracts and uses more than 20 cubic metres or 20,000 litres of water per day, they will now require a ‘Water Abstraction Licence’ from the Environmental Agency. 

The licence allows the Environment Agency to ‘control the level of abstraction to protect both water supplies, and the environment’.

An abstraction licence also ‘guarantees that no one else who applies for an abstraction licence can take the share of water that is already allocated to you’.

In addition, ‘it will specify where you can take the water from, the quantities that you can take and what you can use the water for’. 

Licences are usually valid for 12 years, and carry a presumption of renewal, however you will have to re-apply to ensure that you still require the same amount of water and that it is being used efficiently.

If you wish to abstract water from an underground source, such as a well or borehole, you will usually require a ‘groundwater investigation consent to construct’ and will then need to have a pumping test carried out before you can apply for an abstraction licence.

There are three different types of licence available depending on the intended use. These include: 

  • Full abstraction licence for most types of abstraction over 20 cubic metres per day
  • Temporary licence for abstraction over 20 cubic metres per day over a period of less than 28 consecutive days
  • Transfer licence for moving water from one source of supply to another with no intervening use. 


There are exemptions so please check with the Environment Agency as to whether or not you do need a licence. 

Water - planning for the future

‘An increasing population, demand from agriculture and industry and improving our resilience to drought will all put significant pressures on our water resources. The climate emergency – periods of hotter and drier weather – will only exacerbate these pressures’ – Emma Howard Boyd, Chair of the Environment Agency

If we don’t take action now, England will face serious water shortages, affecting both business and how we each live our lives day-to-day.

The Government has created a National Framework which has explored the long-term needs of all sectors that depend on a secure supply of water.

This includes public water supplies provided by water companies to customers’ homes and business, direct abstraction for agriculture, electricity generation and industry, and the water needs of the environment. 

‘Our modeling assumes that around
700 million litres per day
of water that comes from
unsustainable abstractions will
need to be replaced by other
means between 2025 and 2050′

Regional planning will play a large role in developing a more detailed picture of the future water resource needs of each region across England. The region plans will outline step-changes including:

  • Increasing resilience to drought
  • Delivering greater environmental improvement
  • Long term reductions in water usage
  • Leakage reduction
  • Reducing the use of drought permits and orders
  • Increasing supplies
  • Moving water to where it’s needed

The following graph shows the estimated future water needs of each region in England. 


What is river abstraction?

River abstraction is the withdrawal of water from a river. 

How much water can be abstracted without a licence?

If you use or plan to use more than 20,000 litres or 20 cubic metres or water per day, you will most likely need a water abstraction licence. It is illegal to remove more than 20,000 litres without a licence. 

Why is water abstraction important?

Water abstraction has multiple benefits, the main one being that it can help to reduce the water level of bodies of water, to prevent overflow and possible flooding. 

However, it is important that water abstraction is regulated to ensure there is enough water available to support an increasing population and to safeguard the water supply for the next generation.

How can Aquaco help?

An alternative to abstracting water and therefore applying for one of these licences, is to invest in a water recycling system for Greywater (wastewater from toilets, sinks, showers etc…), Rainwater harvesting or both.

These systems will significantly reduce the amount of water your business will use, but they will also save you time, money and will decrease your impact on the environment by reducing your carbon footprint.

Established in 2009, Aquaco is at the forefront of the research and development of water recycling technologies.

We have an in-house team of engineers who are driving the industry forward by designing and testing new processes, materials and technology in order to provide the most efficient, cost-effective solution for your home or business.

Aquaco manufactures and supplies domestic Greywater and Rainwater recycling systems, right through to huge commercial systems including our flagship projects for Google, Amazon and Facebook offices in London!  

For domestic projects, choose to install our Domestic Greywater recycling system which takes wastewater from toilets, sinks, showers etc… or our Domestic Rainwater harvesting system which collects rainwater from the roof and uses it for showers/sinks.

Or you can choose our Combined system which incorporates both the Greywater and the Rainwater. These systems will not only significantly reduce or even erraradicate the need for mains water, but it will also save you time, money and will decrease your impact on the environment by reducing your carbon footprint. 


Share on facebook
Share on twitter
Share on linkedin