Water makes up most of our bodies and also most of
what we eat. In addition to the water we drink, the average
home in the United States uses 53 liters (14 gallons)
per person each day for washing clothes and
dishes, and 79 liters (21 gallons) a day for bathing and
personal hygiene. The typical home flushes 121 liters
(32 gallons) per day down the toilet. That adds up to
958 liters (253 gallons) of water each day
As interior designers, we want to help our
clients conserve water while maintaining a good quality
interior environment. In order to understand the role
of water in the design of our buildings, let’s start by
looking at how we use it and where it comes from.
Water holds heat well and removes large quantities
of heat when it evaporates. Because water will vaporize
at skin temperatures, our bodies use evaporation to give
off excess heat.
We associate water psychologically with cooling, and
find water and splashing brooks or fountains refreshing.
We employ sprays of water, evaporative coolers, and cooling
towers to cool our buildings. We protect our buildings
from fire with a system of very large pipes and valves
that deliver water quickly to sprinkler systems.
In the past, communities used a municipal fountain
or well as a water supply, and its sculptural form
and central location made it the community’s social
hub. Today, a fountain or pool in the town center or in
a shopping mall becomes a meeting place.
We celebrate the importance of water in our lives
with ceremonial uses, which influence our feelings
about the presence of water in our buildings. Christian
churches practice baptism with water, sometimes including
complete immersion of the person being baptized.
The Jewish tradition includes ritual purification
baths. Catholic churches have containers for holy water
at their entrances, and pools are found in the forecourts
of Islamic mosques.
Rivers and seas have historically connected countries.
With the advent of the industrial revolution, factories
were located along rivers to take advantage of
water for power and for transportation. We use water to
generate electricity at hydroelectric plants.
Water is often the focus of landscaping, inside or
outside of the building. Reflections in water contrast
with plantings and ground covers, and the sparkle,
sound, and motion of water attract our attention. Water
in a garden supports the growth of desirable plants and
animals. Traditional Islamic architectural gardens in
arid regions take advantage of small, tightly controlled
channels to bring water into the center of buildings.
The total amount of water on the earth and in the atmosphere
is finite, unless little icy comets melt in our atmosphere
and contribute a small additional amount. The
water we use today is the same water that was in Noah’s
proverbial flood. Ninety-nine percent of the earth’s
water is either saltwater or glacial ice. A quarter of the
solar energy reaching the earth is employed in constantly
circulating water through evaporation and precipitation,
in a process known as the hydrologic cycle
The most accessible sources of water for our use are
precipitation and runoff. Rain, snow, and other precipitation
provide a very large but thinly spread supply of
relatively pure water. Precipitation can be captured on
a local basis in cisterns (containers for rainwater), a
strategy that is rarely used in the United States but
widely found in other parts of the world where rains are
rare and water is precious. Water that runs off the earth’s
surface results in a more concentrated flow that is more
easily captured in cisterns or ponds. Any daily precipitation
that doesn’t evaporate or run off is retained as
soil moisture. After plants use it to grow, it evaporates
back into the atmosphere.
Groundwater sinks into the soil and fills the open
spaces with water. The upper surface of the groundwater
is called the water table. Groundwater makes up
the majority of our water supply. It can also be used
to store excess building heat in the summer for use in
the building in winter. Groundwater can harm building
foundations when it leaks into spaces below
ground.
The earliest agrarian societies depended upon rain for
agriculture. Historically, rain falling in the countryside
ran into creeks, streams, and rivers, and rivers rarely ran
dry. Rainfall was absorbed into the ground, which served
as a huge reservoir. The water that accumulated underground
emerged as springs and artesian wells, or in
lakes, swamps, and marshes. Most of the water that
leaked into the ground cleansed itself in the weeks,
months, or years it took to get back to an aquifer, which
is a water-bearing rock formation.
Early towns developed near rivers for access to
transportation and wells. Streets sloped to drain in the
river, which ran to river basins and the sea. Later on,
marshy areas were filled in and buildings were built,
along with paved streets and sidewalks. Storm sewers
and pumping stations were constructed to carry away
the water. The rapid runoff increased the danger of
flooding, and concentrated pollutants in waterways.
Water ran out of the ground into overflowing storm sewers,
without recharging groundwater levels.
Today, subdivisions slope from lawns at the top to
street storm drains at the bottom. Once water enters a
storm drain, it dumps out in rivers far away from where
it started. Huge amounts of storm water also leak into
sewer pipes that mix it with sewage and take it even farther
away to be processed at treatment plants. The result
is a suburban desert, with lawns that need watering
and restricted local water supplies.
In most of the United States, the rainwater that falls
on the roof of a home is of adequate quality and quantity
to provide about 95 percent of indoor residential
water requirements. However, a typical U.S. suburban
household could not meet all its water needs with rain
off the roof without modifying the members’ water use
habits. Rainwater can make a major contribution to the
irrigation of small lawns and gardens when a rain barrel
below a downspout or cisterns located above the level
of the garden collect and store water for later release.
For centuries, traditional builders have incorporated
rainwater into their designs. In the world’s drier regions,
small cisterns within the home collect rainwater to supplement
unreliable public supplies. With the advent of
central water and energy supplies in industrial societies,
rainwater collection and use became less common. It
has become easier to raise the funds (with costs spread
to consumers in monthly bills) to build a water treat-ment
plant with the related network of pipes than to
convince individuals to collect, store, and recycle their
own water. An individual who chooses to use rainwater
to flush toilets must pay for this private system up front,
and continue to pay through taxes for municipal water
treatment, so conservation can add expense.
Designing buildings to hold onto even a part of the
50 to 80 percent of rainwater that drains from many
communities requires a radical rethinking of how neighborhoods
are built. Recently, progress has been made in
designing building sites to improve surface and groundwater
qualities. The community master plan for the Coffee
Creek Center, a new residential development located
50 miles southeast of Chicago, was completed in 1998
by William McDonough _ Partners. Coffee Creek itself
is being revived with deep-rooted native plants that
build healthy and productive soil and assure biological
resiliency and variety. A storm water system makes use
of the native ecosystem to absorb and retain rainwater,
while wastewater will be treated on site, using natural
biological processes in a system of constructed wetlands.
In Bellingham, Massachusetts, workers are ripping
up unnecessary asphalt to let rainwater into the ground.
Concrete culverts are being replaced with tall grasses to
slow runoff from parking lots. Cisterns under school
roofs will catch rainwater for watering lawns. Tiny berms
around a model home’s lawn are designed to hold water
until it is absorbed into the ground, and a basin under
the driveway will catch water, filter out any motor oil,
and inject the water back into the lawn.
In Foxborough, Massachusetts, the Neponset River
is being liberated from under the grounds of Foxborough
Stadium. The Neponset was partially buried in culverts
in the late 1940s, and weeds and debris choked the remaining
exposed portion. Plastic fencing and hay bales
appeared to imprison the stream in an attempt to halt
erosion. The river is now being freed into a 20-meter
(65-ft) wide channel and wetlands corridor on the
edge of the new stadium complex, creating a 915-meter
(3000-ft) riverfront consisting of an acre of open water,
four acres of vegetated wetland, and three acres of vegetated
upland. The new 68,000-seat Gillette Stadium will
use graywater to flush the toilets that football fans use
on game days. Storm basins that drain into retention
ponds filter out the oil, salt, and antifreeze that collect
in parking areas. The project also includes a 946,000-liter
(250,000-gallon) per day wastewater treatment facility
and extensive use of recycled construction materials.
Acid rain, a result of air pollution in the northeastern
United States, Canada, and some other parts of the
world, makes some rainwater undesirable. Dust and bird
droppings on collection surfaces and fungicides used for
moss control can pollute the supply. Steep roofs tend to
stay cleaner and collect less dirt in the rainwater.
PROTECTING THE
WATER SUPPLY
Individual water use has increased dramatically in the
recent past. People in Imperial Rome used about 144
liters (38 gallons) a day, and the use in London in 1912
was only 151 liters (40 gallons) per person. Just before
World War II, typical daily use in American cities was
up to about 435 liters (115 gallons). By the mid-1970s,
Los Angeles inhabitants were using 689 liters (182 gallons)
per person each day.
Our current practices use large amounts of highquality
water for low-grade tasks like flushing toilets.
Better conservation practices reserve high-quality water
for high-quality tasks like drinking and preparing
food, reduce overall use, and recycle water for lower
quality uses.
The increasing population and consumption per
person puts pressures on the limited supply of clean
water, threatening world health and political stability.
When people upstream use more than their share of
water, people downstream suffer. Agriculture and industry
use very large quantities of water. Building and
landscape designs often disregard water conservation to
make an impression through water use. Extravagant watering
of golf courses and swimming pools in desert areas
flaunt an affluent lifestyle at the expense of other
priorities. Water pumped out of coastal areas pulls saltwater
into freshwater aquifers.
As the world’s water use rose from about 10 to 50
percent of the available annual water supply between
1950 and 1980, available potable water declined rapidly.
Potable water is water that is free of harmful bacteria
and safe to drink or use for food preparation. The
water carried from the public water supply to individual
buildings in water mains—large underground
pipes—must be potable.
Protecting and conserving our clean water supplies
is critical to our health. Until recently, a reliable supply
of clean water was not always available, and epidemic
diseases continue to be spread through unsanitary water
supplies. Water from ponds or streams in built-up areas
is unsafe to drink, as it may contain biological or chemical
pollution.
Bacteria were unknown to science until discovered
in Germany in 1892. In 1817, thousands of people in
India died from cholera. The epidemic spread to New
York City by 1832, causing panic. A breakthrough came
in 1854, when a London physician showed that local
cases could be traced to one water pump that had been
contaminated by sewage from a nearby house. Cholera
remains a great danger today, with an epidemic originating
in Indonesia in 1961 traveling slowly around the
world to reach Latin America in 1991.
In 1939, typhoid carried through the water supply
killed 30 people at an Illinois mental hospital. Typhus
and enteritis sickened people in Rochester, New York,
when polluted river water was accidentally pumped
into supply mains in 1940. As recently as 1993, cryptosporidiosis
microorganisms in a poorly maintained
public water supply in Milwaukee, Wisconsin, killed 104
people and made 400,000 people ill.
Proper collection, treatment, and distribution of
water protect our supplies. Rainwater has almost no bacteria,
and only small amounts of minerals and gases.
Many communities collect clean water from rain running
down mountainsides into valleys in reservoirs.
They limit human access to these areas to avoid contamination.
Large aqueduct pipes carry the water from
the reservoir to communities, usually by gravity flow.
Communities without access to relatively uninhabited
mountain areas make do with water of less purity from
rivers, or tap underground water flows with wells.
The availability of clean water determines where
homes and businesses are located, and how many people
can live in or visit an area. Water from wells and
mountain reservoirs needs relatively little treatment.
River water is sent through sand filters and settling
basins, where particles are removed. Additional chemical
treatment precipitates iron and lead compounds.
Special filters are used for hydrogen sulfide, radon, and
other dissolved gases. Finally, chlorine dissolved in
water kills harmful microorganisms. The result is an increased
supply of clean water to support the development
of residential and commercial construction.
WATER SUPPLY SYSTEMS
Water mains (Fig. 6-5) are large pipes that transport
water for a public water system from its source to service
connections at buildings. A service pipe installed
by the public water utility runs from the water main to
the building, far enough underground so that it doesn’t
freeze in winter. Within the building or in a curb box,
a water meter measures and records the quantity of
water passing through the service pipe and usually also
monitors sewage disposal services. A control valve is located
in the curb box to shut off the water supply to the
building in an emergency or if the building owner fails
to pay the water bill. A shutoff valve within the building
also controls the water supply.
In rural areas and in many small communities, each
building must develop its own water supply. Most rely
on wells, supplemented by rainwater and by reliable
springs where available.
Wells
Wells supply water of more reliable quantity and quality
than a rainwater system. Water near the surface may have
seeped into the ground from the immediate area, and
may be contaminated by sewage, barnyards, outhouses,
or garbage dumps nearby. Deep wells are expensive to
drill, but the water deep underground comes from hundreds
of miles away, and the long trip filters out most
bacteria. Well water sometimes contains dissolved minerals,
most of which are harmless. Hard water results from
calcium salts in the water, which can build up inside hot
water pipes and cause scaling. Hard water can also turn
soap into scum. A water softener installed on the pipe
leading to the hot water heater will help control it.
Well water is usually potable, if the source is deep
enough. It should be pure, cool, and free of discoloration
and odor problems. The local health department
will check samples for bacterial and chemical content
before use. Wells are sunk below the water table so
that they are not affected by seasonal fluctuations in the
water level. Pumps bring the water from the well to the
surface, where it is stored in tanks under constant pres-
sure to compensate for variations in the flow from the
well. The water can be filtered and chlorinated at this
point. Pumps and pressure tanks are usually housed in
outbuildings kept above freezing temperatures.
The use of water should be related to its quality. Almost
every North American building has potable water.
In most buildings, the majority of this clean water is
used to carry away organic wastes.
When water is used efficiently and supplied locally,
less water is removed from rivers, lakes, and underground
aquifers. Less energy and chemicals are required
for treatment and delivery, and less storm water is
wasted and discharged to pollute rivers, eliminating the
need for additional expensive water treatment plants.
Interior designers can help to conserve clean water by
specifying efficient fixtures and considering the use of
recycled water where appropriate.
Municipal Water Supply Systems
The water in a community’s water mains is under pressure
to offset friction and gravity as it flows through the
pipes. The water pressure in public water supplies is usually
at or above 345 kilopascals (kPa), which is equal
to 50 lb per square in. (psi). This is also about the maximum
achieved by private well systems, and is adequate
pressure for buildings up to six stories high. For taller
buildings, or where the water pressure is lower, water is
pumped to a rooftop storage tank and distributed by
gravity, a system called gravity downfeed. The water storage
tank can also double as a reserve for a fire protection
system.
Once the water is inside the building, its pressure
is changed by the size of the pipes it travels through.
Bigger pipes put less pressure on the water flow, while
small pipes increase the pressure. If the water rises up
high in the building, gravity and friction combine to decrease
the pressure. The water pressure at individual
fixtures within the building may vary between 35 and
204 kPa (5–30 psi). Too much pressure causes splashing;
too little produces a slow dribble. Water supply
pipes are sized to use up the difference between the service
pressure and the pressure required for each fixture.
If the pressure is still too high, pressure reducers or regulators
are installed on fixtures.
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