ENVIRONMENT AND ENERGY
23
further actions on flood risk reduction are taken.
Over 70% of this increase can be attributed to
economic growth in flood-prone areas, in addition
to climate change. The Organisation for Economic
Co-operation and Development cites climate
scenarios based on modelling undertaken by
Winsemius and Ward (2015), which shows that
the flood damage in urban areas could reach
USD0.7–1.8-trillion per year by 2080. The release of untreated wastewater from
expanding human settlements and increasing
industrial production generates physical,
chemical, and biological pollution, impacting
both human and environmental health. The
presence of faecal coliforms, which originate
from human and animal excreta, is used as
an indicator of the presence of all potential
pathogens in surface waters.
Globally, drought is arguably the greatest single
threat from climate change but locally, sea-level
rise (affecting coastal areas) or other threats could
be larger (for example areas that are extremely
vulnerable to floods or landslides). Consequences
of drought can be very significant from a socio-
economic and environmental perspective. Its
impacts range from lower agricultural productivity
and disruptions of ecosystem functioning to
increased food prices, while insecurity and famine
can trigger mass migration. Early findings from the global water quality
monitoring programme show that severe
pathogen pollution affects around one-third of all
river stretches in Africa, Asia, and Latin America,
putting the health of millions of people at risk.
Even though sanitation coverage has increased
and treatment levels have improved in some
countries, such improvements need to happen
simultaneously in order to avoid increased
contaminant loadings. This could probably
explain the increased loadings of faecal coliform
bacteria (FC) observed in Africa, Asia, and Latin
America over the past two decades.
Some of the measures to increase the
resilience to drought events include the
acceptance of wastewater as a reliable source
of water for agriculture and many other uses.
Global water demand is predicted to increase
significantly over the coming decades. In
addition to demand from the agricultural sector,
which is currently responsible for 70% of water
abstractions worldwide, large increases are
predicted for industry and energy production.
Changing consumption patterns, including
shifting diets towards highly water-intensive
foods such as meat (that is, 15 000ℓ of
water are needed for 1kg of beef) will worsen
the situation. It is therefore unsurprising
that the World Economic Forum (WEF) has
consecutively assessed the water crisis as
one of the major global risks over the past five
years. In 2016, the water crisis was determined
as the global risk of highest concern for people
and economies for the next 10 years.
Organic pollution (measured in terms of
biochemical oxygen demand – BOD) can have
significant impacts on inland fisheries, food
security, and livelihoods, severely affecting
poor rural communities that rely on freshwater
fisheries. Severe organic pollution already affects
around one-seventh of all river stretches in
Africa, Asia, and Latin America, and has been
steadily increasing for years. The release of
nutrients (nitrogen, phosphorus, and potassium)
and agrochemicals from intensive agriculture
and animal waste can further accelerate the
eutrophication of freshwater and coastal marine
ecosystems, and increase groundwater pollution.
Most of the largest lakes in Latin America and
Africa have seen increasing anthropogenic
loads of phosphorus, which can accelerate
eutrophication processes.
AMBIENT WATER QUALITY
The availability of water resources is intrinsically
linked to water quality. The pollution of surface
water and groundwater may prohibit its
different uses in the absence of costly pre-
treatment. The deterioration of water quality
is expected to increase further in the next
decades, particularly in resource-poor countries
in dry areas, which will further endanger human
health and the environment, while constraining
sustainable economic development. Increased discharges of inadequately treated
wastewater, resulting from economic and
industrial development, intensification and
expansion of agriculture, and growing volumes
of sewage from rapidly urbanising areas, are
contributing to the further degradation of water
quality in surface and groundwater around the
world. As water pollution critically affects water
availability, it needs to be properly managed, in
order to mitigate the impacts of increasing
water scarcity. PA
www.plumbingafrica.co.za October 2017 Volume 23 I Number 8