- Project plans
- Project activities
- Legislation and standards
- Industry context
- Specialist wikis
Last edited 09 Dec 2020
Water is an increasingly scarce resource. As population increases, and climate change makes rainwater patterns less predictable, it is becoming more important that we reduce the amount of water that we consume and discharge into the sewerage infrastructure.
In addition, the treatment of water to make it suitable for drinking and other uses consumes a considerable amount of energy. Treating water to make it suitable for drinking just to use it for purposes that do not require this level of treatment, such as watering gardens or flushing toilets, is extremely wasteful.
Environmental concerns, utilities bills and the imposition of restrictions such as requirements for sustainable urban drainage systems and hosepipe bans means that people are increasingly looking to re-use or re-cycle water.
Typically water is categorised within one of three broad groups, with the degree of contamination increasing and so the number of suitable uses decreasing and the treatment requirement increasing:
- Fresh, potable water or ‘drinking water’ is sometimes referred to as ‘white water’.
- Wastewater from showers, baths, washbasins and washing machines that is not considered to be potentially dangerous, is referred to as ‘greywater’.
- Water from toilets that may be contaminated with hazardous material is referred to as ‘blackwater’ (or sometimes brown water, foul water, or sewage). Some definitions of blackwater also include water from kitchen sinks, dishwashers and waste disposal units which may contain food particles.
It is possible to collect greywater and, after treatment, use it for purposes that do not require drinking water quality, such as toilet flushing and garden watering. This greatly reduces the demand on mains water as well as reducing the volume of water discharged into sewage systems.
As well as conserving water this will also save users money on their water bills (if they have water metres installed). According to the Environmental Agency (2011), greywater recycling systems have the potential to reduce the amount of mains water used in the home by about a third.
The limitations of initiatives such as rainwater harvesting and greywater harvesting are that even though it reduces demand for mains water, it does not actually contribute to a reduction in water consumption. In addition, long payback times combined with small storage volumes mean it can be less effective than other water conservation measures.
 Related articles on Designing Buildings Wiki
- Delivering water efficiency in commercial buildings: A guide for facilities managers.
- Environment Agency.
- Flood and Water Management Act.
- Green roof.
- Greywater recycling at the Millennium Dome.
- Hosepipe ban.
- Marine energy and hydropower.
- Passive water efficiency measures.
- Planning for floods.
- Rainwater harvesting.
- Reed bed.
- SuDS - is there light at the end of the tunnel?
- Sustainable urban drainage systems.
- Types of water.
- Water consumption.
- Water management.
- Water quality.
Featured articles and news
Virtual connections can help apprentices keep up with training requirements.
NEC and IWFM announce the final edition of this suite of contracts.
The convergence of mathematics, computation and design.
Her circuitous, but rewarding construction career path.
CIC publishes its carbon zero strategy for organisations.
Various techniques can be deployed to open this type of movable bridge.
Her development as a thinker and writer. Book review.
Smart motorway strategies.
Actuate UK urges change of deadline to at least December 2022.
Study shows harmful impact of late payments on SME personnel.
Upcoming changes to the commercial supply and purchase of chemicals.
CLC introduces card for learners.
CIOB members recognised for public procurement.
Experts discuss the complex issues damaging the supply chain.