Water
Over the last few years much attention has been given to energy and energy conservation, which has deflected attention away from concerns about water. The UK concrete sector is very aware of the importance of water, especially when considered alongside the likely impacts of global warming and climate change.
Water is a finite resource. And, unlike oil, there is no
substitute for water. Of all the water on Earth, less than one
percent is easily accessible freshwater for human consumption, and
this water has to be shared with the natural environment. The small
amount of water that we are left with is unevenly distributed in
space and time, and is sometimes polluted. Over a billion people
still lack access to improved water supplies and one-third of us
already live in water stressed areas. If present levels of
consumption continue, two-thirds of the global population will live
in areas of water stress by 2025. Increasing human demand for water
coupled with the effects of climate change mean that the future of
our water supply is not secure.
In the UK we have historically taken water too much for
granted as our wet maritime climate which has provided a relatively
assured supply of domestic, agricultural and industrial water.
Recent floods, however, confirm the unpredictability of our water
resources; we had eight drought years in the past fourteen years
and although 2000 and 2004 were wet years, the trend is towards
less rainfall in the south of England and more in the north and
west.
It may come as a surprise but the truth is that the UK has
less available water per person than most other European countries.
London is drier than Istanbul, and the South East of England has
less water available per person than the Sudan and Syria. Water is
scarce in parts of Scotland, Wales and Northern Ireland as well as
in England - large scale drought is already occurring in the UK,
with the lowest rainfall, groundwater and reservoir levels for
decades.
Each person in the UK currently uses about 150 litres of water every day. This has been rising by 1% since 1930. This consumption level is not sustainable in the long-term. If we do not take action now, climate change, population shifts and behaviour mean the UK will face increased water stress in the future.
All construction products have embodied water in them and the
UK concrete sector is doing all it can to
minimise its impact on this resource.
Embodied water
Embedded water refers to the amount of water required to
produce a product from start to finish. Embedded water is most
commonly used with reference to agricultural products but may be
applied to non-agricultural goods as well, such as construction
products.
Therefore even your home has water embedded in it. Though no
studies have been done on homes in the UK, a 2004 study in
Australia estimated that a typical Australian house represents
about 15 years worth of operational water 15 years of water for
cooking, cleaning, washing, drinking, toilet flushing and gardening
all embedded within a single home 1. This study
estimated that a kilo of concrete has about two litres of
embedded water, a kilo of timber about 20 litres, a kilogram of
steel about 40 litres, a kilo of aluminium about 88 litres, and
that a kilogram of plastic has about 185 litres of embedded water.
It is safe to assume that a British home will also have a great
deal of water embedded in it.
References and further reading
1. G Treloar, M McCormack, L Palmowski, and R Fay, Embodied
Water of Construction. Environment Design Guide, The Royal
Australian Institute of Architects, 2004