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Ecosystem
degradation
Reusing processed
sewage
Contaminated
food provision
Drinking water treatment
Global water withdrawal
percentage by sector
Waste water
discharge
Sewage sludge
flora and fauna that are crucial in the natural cycling of these ecosystems,
thus ensuring their long-term function. Indeed, many rivers are straight-
ened and wetlands and marshes drained or dried out behind dikes to ensure
agricultural expansion, however, this invariably causes higher water velocity,
higher risk of floods, and increased organic pollution further downstream
(Bruijnzeel 2004; UNEP, 2005). These ecosystems also help buffer global
climate change (Nepstad 2007). Hence, restoration must not address the
catchments in terms of forests and riverine vegetation including ground
layer, but must also ensure the natural meandering pathways and the flood
marshes and wetlands to ensure proper filtration and buffering mecha-
nisms against extreme flows. Worldwide, nearly 900 million people still do
not have access to safe water (UNDESA 2009)
Restoration to re-establish diverse grazing and cropping systems, partially
restoring naturally supplementing plants and trees in more diversified crop-
ping and grazing systems, combined with green technology in irrigation
efficiency, could help drastically reduce the 70–90% of the water currently
consumed and partly wasted by agriculture. This, in turn, would increase
water availibility to cities, improve water quality, as well as make more water
available for irrigation. Such cropping systems capture more water through
wetlands, marshes and lakes during flood seasons, rather than this causing
floods and marine pollution as a result of seasonally extremely high veloc-
ity and volume. This is particularly important for countries like Pakistan,
where a near doubling in population from 184 million people in 2010 to a
projected 335 million people by 2050 (UN population division, 2007) – and
already facing water scarcity and flood challenges. Pakistan is one of many
states that will need to address new ways to secure sufficient water supply
for upholding food security in the future.
Restoration is financially viable (TEEB, 2009): Cities like Rio de Janeiro,
Johannesburg, Tokyo, Melbourne, New York and Jakarta all rely on pro-
tected areas to provide residents with drinking water. They are not alone
– a third of the world’s hundred largest cities draw a substantial proportion
of their drinking water from forest protected areas (Dudley and Stolton
2003). Forests, wetlands and protected areas with dedicated management
actions often provide clean water at a much lower cost than man-made sub-
stitutes like water treatment plants for example in Venezuela: the national
protected area system prevents sedimentation that if left unattended could
reduce farm earnings by around USD 3.5 million/year (Pabon-Zamora
et al
. 2008).
Figure 8:
As water is extracted and used
along the supply chain, both the quality and
quantity of water available is reduced.