The role of urban agriculture within
the urban metabolism – a critical
Robert Biel
UCL Development Planning Unit
Water poverty is not the same as scarcity
Entitlements argument (Sen 1982) , as counter to
Malthusian assertion that poverty derives from
As with food, water poverty can therefore
undoubtedly exist even in a context of plenty
The blockage is thus not absolute supply, but rather
limitations in governance, distribution etc.
Nevertheless, there is a strong argument that water
may be becoming objectively scarce (Marks 2007)
... for many reasons, including industrial demands on
water ... most recent developments arguably
attempt to stave off entropy at the expense of
increased intensity of water use, e.g. semiconductor
industry (Williams et al 2002) or in context of Peak Oil
(Lydersen 2007)
But most importantly for our purposes, the problem
is related to food scarcity/crisis ... because ...
... food is embodied water
You consume about 1000x as much water through
your food as the water you drink
... roughly one litre of water for each calorie (FAO
This poses severe constraints, which from one angle
can be addressed at the institutional/governance
level (Molden and de Fraiture 2004)
But the other necessary angle is ...
... change in agricultural methods!
some of the unsustainably high water consumption
undoubtedly results from failings of the mainstream
food system:
... high input
... not just of energy and of chemicals, but of water
e.g. effect of Green Revolution lowering water tables
is well documented (Buchholz 1984)
Key to everything is
maintaining soil structure
(Howard 1943)
we thereby minimise not
only demands on water
input but leaching of
nutrients by water
it is possible to aspire to a
viable agriculture which
focuses mainly on the
harvesting and flow of water
... as in the case of Zimbabwean
farmer Zephania Phiri Maseko
(Lancaster 1996)
The political economy enters a phase which is
chaotic, but also one of opportunity (Biel, forthcoming)
This crisis triggers some kind of reflex, but what
On the Malthusian premise, the response would be
conflictual, but this is not necessarily true ...
... it can be a co-operative reflex
Co-operation and regime solutions are perfectly
compatible with both game theory and evolutionary
models (Nowak 2006)
Research now reveals how crowds, far from
‘stampeding’ in an irrational manner, tend to
increase their co-operative and rational behaviour in
situations of stress or danger (Bond 2009; Winn 2009)
This can apply very well to water. In researching a
book on ‘water wars’, when Wendy Barnaby found
that co-operative responses to water scarcity
overwhelmingly prevail over the conflictual, her
publishers cancelled their interest (Barnaby 2009)
This confirms a lot of previous research on ‘water
wars’ (Wolf 1999, Alam 2002). While most of this
literature is in the IR field, but there is a strong
hypothesis that this would be reflected in local
resource management too
Although internecine conflict is less than one might
think, there is undoubtedly a defensive struggle
against attempt by powerful interests to ‘grab’ water
When in El Salvador, decentralisation became an
excuse to privatise it, people protesting this were
accused under an anti-terror law (Cispes 2007)
... but I don’t think this will succeed in suppressing
c.f. Cochabamba Water Revolt in Bolivia from 2000,
againstWorld Bank attempts to ‘privatise’ water in
the interest of the US Bechtel corporation; or the
failure Enron’s 1998 attempt to launch internet
speculative water economy via its subsidiary Azurix
“cities as hybrid phenomena that emerge from the
interactions between human and ecological
processes.” (Alberti 2008: 6) ; they are therefore
complex, multiequilibria systems which do not
follow a single trajectory to a single point of
... interface between natural systems and
social/institutional ones
Water can be regarded as an important means of
transmission within this metabolism
... but that’s only a general proposition: we must
strive to understand it concretely
... achieved through a
combination of mulches and
green manures
phacelia tanacetifolia
Hypothesis is that by use of similar sustainable
methods, rainwater should suffice
... this is confirmed by some recent research (e.g.
Veríssimo 2010)
In this hypothesis, the more successful the
conversion to low-input methods, the more selfcontained the plot, from a water viewpoint (the
same would apply to other inputs)
... this provides a brilliant defence against water
poverty ...
... but does it weaken insertion of urban agriculture
in the metabolism?
We would have to seek the answer by looking
somewhere around the diversity of forms of urban
agriculture; it is perfectly OK for some forms to be
more self-sufficient and others more strongly
interdependent with other parts of the metabolism
In order for urban agriculture to make a serious
contribution to the goal of ‘cities feeding people’, it
must include certain organisational forms where the
production is far higher than the food needs of the
people engaged in it
... the metabolism insertion of such high-productivity
would be far higher than for the subsistence sector
Example: the Will Allen model
Allen’s model probably functions to some extent as a
closed-loop system, inasmuch as the salad crops act
to purify the water in a manner analogous to river
plants: even Allen was surprised to learn that the
system spontaneously developed a state of
equilibrium in this respect
At the same time,
insertion in social
networks is very
It is possible as part of a diverse approach to include
certain forms which intensively make use of those
resources (grey water, also compostable waste etc.)
which are available within the urban system
... this may be achieved through an extension of the
industrial ecology model. Just because it is not
subsistence based, this high-productivity
department of urban agriculture necessarily fosters
distribution and social networks
These resources are nevertheless drawn into smallscale loops within the individual project, while at the
same time fostering wider loops at the community,
district or city level

The role of urban agriculture within perspective Robert Biel