This is an excellent article that presents information supporting water recycling in urban settings, which demonstrates how easily recycled water to irrigate vertical farms.
Heinz, I, Salgon, M. & Koo-Oshima, S. (20110. Water reclamation and intersectoral water transfer
between agriculture and cities - a FAO economic wastewater study. Water Science, & Technology,
63(5), pp.1067-1073. Retrieved July 6, 2011 from LexisNexis Academic.
ABSTRACT
Cost–benefit studies on replacing conventional agricultural water resources with reclaimed water
in favour of cities are still rare. Some results of a study under auspices of the Food and
Agriculture Organisation (FAO) are presented. By means of an illustrative example at Lobregat
River basin in Spain, it could be proved that reclaimed water reuse and intersectoral water
transfer can result in economic and environmental benefits at the watershed level. The
agricultural community faces cost savings in water pumping and fertilising, increases in yields and
incomes; the municipality benefits from additional water resources released by farmers. Farmers
should be encouraged to participate by implementing adequate economic incentives. Charging
farmers with the full cost of water reclamation may discourage farmers from joining water
exchange projects. Particularly in regions with water scarcity, investments in reclaimed water
reuse and water exchange arrangements usually pay back and are profitable in the long term.
Key words 9 cost–benefit analysis, intersectoral water transfer, irrigated agriculture, municipal
water supply, wastewater reuse, water exchange, water reclamation
INTRODUCTION
In arid and semi-arid regions, treated wastewater (reclaimed
water) reuse is an effective measure to tackle water scarcity
problems. This applies particularly to countries where irrigated
agriculture, usually the biggest water user, plays a major
role in the economy. It is also of note that in most cases
treated and untreated wastewater is still being discharged into
rivers causing adverse environmental and even health
impacts. Certainly, there are many regions where reclaimed
water reuse is already practised for irrigation and other
purposes. Irrigation with reclaimed water helps to grow
more food and preserve water resources. It is quoted that at
least 10% of the world’s population is thought to consume
food produced by irrigation with wastewater (WHOFAO-
UNEP 2006). In southern countries of Europe, 2% of
the total treated effluents are reused after reclamation, mainly
for agricultural irrigation. In the Mediterranean Region, reuse
is increasing at a rate of 25% per year (Jime´nez & Asano
2008). In Spain, Lazarova & Bahri (2008) claim that 22% of
the collected wastewater is reused in agriculture. With
increasing water scarcity and growing populations, the
importance of water reclamation and reuse will rise. In
addition, our thesis is that scarcity problems in cities can be
mitigated by intersectoral transfer of freshwater replaced by
farmers who use treated wastewater with economic benefits
both for farmers and the society.
Wastewater treatment and reuse projects require effective
technical infrastructures and economically efficient and
socially acceptable solutions: reuse projects must be financially
feasible and affordable. An economic framework
including assessment criteria is barely needed for the evaluation
of economic and financial feasibility of wastewater reuse
projects (Asano et al. 2007).
Numerous publications in the field of wastewater reuse
technologies exist. Many applications worldwide are
described in Jime´nez & Asano (2008). One example can be
found in Virginia, South Australia, where the effluents from
Ingo Heinz (corresponding author)
Ex-University Dortmund,
Germany,
E-mail Ingo.Heinz@uni-dortmund.de
Miquel Salgot
University of Barcelona,
Spain,
E-mail salgot@ub.edu
Sasha Koo-Oshima
Food and Agriculture Organisation of
the United Nations,
Rome,
E-mail Koo-Oshima.Sasha@epa.gov
doi: 10.2166/wst.2011.292
1067 & IWA Publishing 2011 Water Science & Technology 9 63.5 9 2011
the Bolivar wastewater treatment plant in Adelaide are
transferred to the Virginia area, north of Adelaide, for irrigation
of horticultural crops. The water reclamation plant
incorporates dissolved air flotation and filtration processes.
Apart from it, measures to increase the amount of reclaimed
water available such as the development of an aquifer storage
and recovery system have been investigated (Marks et al.
2002). In the US, agricultural irrigation is the biggest water
reuse activity. In the State of California, 46% of the total
volume of reclaimed water is used for this purpose (California
StateWater Resources Control Board 2002). For example, the
city of Santa Rosa treats to a tertiary level the effluents of five
different cities in the Sonoma County. More than half of the
water produced is used to irrigate approximately 2,310 ha of
farmlands. During the winter months when there is no
demand for irrigation, the effluent is used to recharge an
aquifer and produce electricity using the energy from geysers
(California Energy Commission 2002; Asano et al. 2007).
Some economic analyses of wastewater reuse for different
purposes, such as agricultural and landscape irrigation, industrial
applications and potable reuse, can be found. They
address both the costs and the benefits of water reclamation
(Aquarec 2006a, b; Asano et al. 2007). Farmers who convert
to reclaimed water can lower their expenses on irrigation if
the cost of reclaimed water is cheaper than that of conventional
sources. Additional economic benefits can occur
thanks to the improved availability of reclaimed water,
which may allow increases in yields and sales revenues;
especially in water shortage periods, farmers can prevent
losses.
Moreover, farmers can release conventional water for
cities by replacing it with reclaimed water generated by those
or other cities. Such a water exchange (or intersectoral water
transfer) can result in manifold benefits for municipalities,
such as cost savings in water extraction, water delivery,
water resources development, drinking water treatment, and
removal of nutrients in wastewater treatment (Segui et al.
2008). Further benefits may include improvements in the
economic development of urban areas due to increased
water availability (e.g. industries, tourism). Beneficial impacts
on nature on water bodies and aquatic habitats can result from
reduced overexploitation of aquifers, rivers and lakes, from less
wastewater discharges and from prevented seawater intrusion
(Mujeriego et al. 2007). However, not all of those impacts can
be simply evaluated in economic terms (Aquarec 2006b).
On the other hand, environmental and health risks can
decrease the benefits if the prescribed legal requirements
for reclaimed water quality and application are not met.
Wastewater reuse for irrigation is practised worldwide,
often without any treatment or with a combination of
only partial treatment, sometimes without wearing personal
protective equipment (shoes, gloves) or washing of
produce to protect consumers of raw vegetables (WHOFAO-
UNEP 2006; Asano et al. 2007). The biggest irrigated
area using untreated wastewater in the world is located in
Mexico, D.F., where the majority of this water is reused for
agricultural irrigation (Jime´nez 2008a). In the area presently
receiving wastewater, the Mezquital Valley (named
also Tula Valley), a century ago agriculture could not be
developed due to the lack of water. Currently, around
74,000 farmers irrigate 76,000 ha using mainly the wastewater
from Mexico City. Wastewater with organic matter
and nutrients for plants is greatly appreciated by the
farmers. Due to its fertilising content, leasing prices of
wastewater irrigated agricultural land increased by a
factor of nearly three compared with rain-fed agricultural
land, and it is further possible to grow two or three crops
per year instead of just one. The disadvantage is the
potential negative effects on health: a 16-fold increase in
morbidity by helminths in children in comparison to
unexposed nearby areas has been reported (Jime´nez
2008b). Even though there exists a self-purifying capacity
of water (flowing in pipelines, channels, and streams and
through the soil, as well as when it is stored in impoundments),
it is not enough to reach good quality for irrigation
without hazards. Additional treatment plants are being
planned to treat Mexico City wastewater, which will
improve the sanitary conditions in the area and will
increase the cost of water supply.
As cost–benefit studies on intersectoral water exchange
are still rare, some of the results of a research project, funded
by the Food and Agriculture Organisation (FAO), will be
presented (Heinz et al. 2008). In this research project, eight
case studies were carried out in Spain and Mexico. One of
them, located at the Llobregat River Delta in Spain, will be
used as an illustrative example.
MATERIALS AND METHODS
The Llobregat River Basin is situated in the North-East of
Spain close to the city of Barcelona. During the last decades,
the river Llobregat has been highly polluted by industrial and
urban wastewaters and experiences periodic floods and
droughts. Overexploitation, and furthermore the occurrence
of natural salt formations and the corresponding mining
exploitations in the upper basin, are causing an increase
in the water salinity and consequently salinisation of the
1068 I. Heinz et al. 9 Water reclamation and intersectoral water transfer between agriculture and cities Water Science & Technology 9 63.5 9 2011
aquifers. Since 1991, a comprehensive programme of wastewater
treatment plants has been implemented along the
Llobregat River Basin. A water reclamation programme has
been planned and in part already implemented (Age`ncia
Catalania de l’Aigua 2007). In the considered area, there are
two main wastewater treatment plants: the Sant Feliu de
Llobregat plant and the Prat de Llobregat plant, both with
tertiary treatment. Especially the latter plant – with a wastewater
generation of around 120 Mm3/yr one of the biggest
treatment plants in Europe – is typically a multi-purpose
project that aims also to recharge aquifers, improving the
stream flow and quality of the river, irrigating wetlands and
preventing seawater intrusion with the adequately treated
effluents.
In the following, the first plant has been selected as an
example to show the potential economic efficiency of the
water reclamation and intersectoral water transfer. The effluent
from this plant of 19 Mm3/yr could be used for irrigation
purposes in an agricultural area of more than 600 ha, with
mainly herbaceous crops. The existing tertiary treatment
consisted only of sand filter and disinfection, and only a
few farmers use this water due to its high conductivity of
2.95 dS/m on average. Due to the high salinity of the effluent
the farmers mix it with well water. The farmers prefer to use
the aquifer and the Llobregat river water as the main
resources. In drought periods, however, the farmers have to
use it compulsorily to a greater extent. Normally, the permission
to use water from the Lobregat river is 1.5 m3/s. In water
shortage periods, however, the use is reduced to 0.8 m3/s. In
order to make the tertiary effluents more acceptable for the
farmers the conductivity must be reduced by upgrading the
treatment plant.
Furthermore, the Catalonian Water Agency (ACA)
initiated the construction of a seawater desalination plant
with a capacity of 60 Mm3/yr in order to augment the water
availability for the municipality of Barcelona.
In order to assess the economic efficiency of the wastewater
reuse the cost and benefits must be compared. The cost
components include the capital cost, the operation and
maintenance costs of the upgraded tertiary wastewater treatment
and the cost of conveying the reclaimed water to the
fields. The economic benefits for the farmers include not only
the cost savings in water pumping (e.g. groundwater) and in
fertilising (due to the nutrient content of reclaimed water) but
also increases in yields. A surplus of the economic benefit
above the cost can lead to additional income of farmers.
However, the actual income increase depends on how much
they have to pay for the reclaimed water. If the cost exceeds
the benefit, the water reclamation project would not be
economically efficient, unless there are further beneficial
impacts. As mentioned already, they can result from the
water exchange between cities and farmers, who replace
freshwater with treated wastewater.
The economic efficiency of such a water exchange
depends on the costs of extraction, storage and conveyance
of freshwater to the cities and on the cost savings in municipal
water services in the entire area of influence, such as
reduced expenses in groundwater abstraction, in drinking
water treatment due to reduced pollution of rivers and in
water resource development.
Another methodological approach refers to the economic
value of the increased municipal water supply. This approach
does not differ substantially from the first one. The water
value indicates both the cost of and the willingness to pay for
obtaining additional water. If FW is the freshwater released
and u the unitary (marginal) value of water, the economic
benefit of water transfer H to cities can be computed by
H ¼ FW u ð1Þ
The water value u is naturally influenced by the costs of
water infrastructures (mainly supply and sanitation). The
value can change in the course of time. It may rise due to
growing cost of intersectoral water transfer or it may decrease
due to the water user’s reduced willingness to pay as a
consequence of the increased urban water supply. In the
long term, u rises with increasing water scarcity if precipitation
diminishes or water demand is growing. Scarcity costs
may be interpreted as scarcity rents that emerge wherever the
water availability does not satisfy water demands (Heinz et al.
2007); they reflect the costs needed to reduce the water
shortage in the future.
RESULTS AND DISCUSSION
The investment cost of upgrading the tertiary treatment at the
Sant Feliu de Llobregat plant to make the effluent better
suitable for agricultural irrigation, plus the cost of a pipeline
network, amounts to 1.112 Mh. Pumping the effluent to the
fields would cost 208,390 h/yr. As Table 1 shows, the total
cost of water reclamation (column 5) exceeds the total added
value for farmers (column 4). So, this wastewater reuse
project would not be economically efficient in the mentioned
circumstances. However, the question arises whether there
are further benefits resulting from intersectoral water transfer.
Even in such a case the farmers will reject converting to
1069 I. Heinz et al. 9 Water reclamation and intersectoral water transfer between agriculture and cities Water Science & Technology 9 63.5 9 2011
reclaimed water if they would have to pay the full cost. In
contrast, as Table 1 indicates, they would be better off if they
were charged in part, such as with the conveyance cost
only, resulting to an income increase of around 253,000 h/
yr. The question remains whether this is a sufficient economic
incentive to use reclaimed water instead of conventional
resources.
Table 2 shows the results of the cost–benefit analysis for
the same wastewater reuse project as described above, but
modified by the consideration of intersectoral water transfer.
At this example, the current domestic water price of 1.11 h/m3
in the research area is used as a lower estimate of the
economic value of the released freshwater. To some extent
this price contains infrastructure, scarcity and environmental
costs. Water users in Catalonia are charged a special tax
(around 26% of the domestic water price) in order to guarantee
the long-term water supply of towns and to improve the
quality of both surface and groundwater (Age`ncia Catalana
de l’Aigua 2007).
In contrast to the results shown in Table 1, wastewater
reuse in agriculture becomes economically efficient as the
benefits of the city are additionally regarded. The added value
or economic net-benefit of water exchange between agriculture
and municipality can be estimated to be more than
6.9 Mh/yr (Table 2).
As mentioned, environmental costs and benefits and
other impacts should be considered as well; however, they
are difficult to monetarise. In literature, many approaches can
be found to evaluate such so-called ‘‘intangible’’ impacts or
‘‘externalities’’ (Griffin 2006; Aquarec 2006a). In principle, the
externalities can be evaluated by expressing the importance
people give to the impacts concerned (such as the value of
wetlands irrigated by wastewater). The usual approach is to
explore the willingness of people or communities to bear the
cost of obtaining the benefits or of preventing adverse
impacts. If impacts cannot be monetarised easily or not at
all (e.g. certain health risks) they should be taken into
account by using physical impact measures.
The unitary cost of water exchange of around 0.22 h/m3
may be compared with the domestic water price of 1.11 h/m3
as a lower estimate of the water value. Obviously, there is a
big gap between this cost and the willingness to pay for water.
This difference indicates a lower estimate of the unitary
benefit added for the citizens. Water exchange between
farmers and the city would provide additional water for
high-valued purposes at considerably lower cost. In terms
of cost–benefit analysis, an expansion of the intersectoral
water transfer could be worthwhile until a maximum net
benefit might be achieved. However, constraints such as the
limited availability of freshwater used by farmers and financial
barriers must be taken into account.
Water prices should cover both the infrastructure and the
scarcity costs as far as possible. In reality, this is not the usual
case for political reasons (for instance, due to low income of
poor families). There are many examples where even the
infrastructure costs are not fully recovered by water prices,
Table 1 9 Costs related to water reuse – an example in the Llobregat River Delta, Spain
Cost savings in water pumping
(1,000 h/yr)
Cost savings in fertilising
(1,000 h/yr)
Increase in sales revenue
(1,000 h/yr)
Added value in agriculture*
(1,000 h/yr)
Cost of reclaimed water**
(1,000 h/yr)
62.6 10.4 388.1 461.1 798.2
*The added value includes the cost savings in water pumping and fertilising and the increase in sales revenue.
**The total cost of reclaimed water of 798,216 h/yr includes the annual capital cost of 77,384 h/yr and 512,442 h/yr, the operation and maintenance cost of wastewater treatment, plus
the cost of conveying the reclaimed water to the fields of 208,390 h/yr. The annual capital costs are computed by multiplying 1.122 Mh, the investment costs of the new tertiary treatment
plant and pipeline network, with the capital recovery factor of 0.06897 (average service time 35 years and rate of interest 6%).
Table 2 9 Net benefits of intersectoral water transfer – an example
Cost of water exchange*
(1,000 h/yr)
Value added in agriculture
(1,000 h/yr)
Economic value of improved water availability for the city**
(1,000 h/yr)
Net benefit of water exchange
(1,000 h/yr)***
1,608.9 461.1 8,103 6,979.8
*The total cost of water exchange of 1,608,916 h/yr includes 798,216 h/yr, the total annual cost of the reclaimed water (Table 1) plus 810,700 h/yr, the extraction and conveyance cost of
freshwater. No capital cost of the latter is considered as it is assumed that the existing infrastructure is sufficient to extract and distribute the released water to the city. The unitary cost
of water exchange is around 0.22 h/m3, i.e. 1.6 Mh/yr divided by approximately 7.3 Mm3/yr, the water volume exchanged.
**The freshwater release of approximately 7.3 Mm3/yr multiplied with the domestic water price of 1.11 h/m3 renders a lower estimate for the economic benefit of 8.103 Mh/yr.
***The net benefit of water exchange is the sum of the value added in agriculture of 461,100 h/yr and the economic value of improved water availability for the city of 8,103,000 h/yr
minus the total cost of water exchange of around 1,608,900 h/yr (column 1).
1070 I. Heinz et al. 9 Water reclamation and intersectoral water transfer between agriculture and cities Water Science & Technology 9 63.5 9 2011
like in Catalonia, Spain (Age`ncia Catalana de l’Aigua 2007).
Ideally, water prices should cover also the environmental
costs associated with the provision of municipal water services;
however, they are often ignored. The European Water
Framework Directive (WFD) commits the Member States to
take into account the principle of cost recovery (WFD 2000).
However, it should be taken into account that pricing is not
the only financing instrument to achieve cost recovery. Apart
from water tariffs, cost recovery can be ensured also by
subsidies provided by governments or by transfers from
international organisations. But in order to assess the economic
efficiency of intersectoral water transfer projects, u
should reflect the true value of water as far as possible.
Charging farmers with the full cost of water reclamation
can discourage them from converting to irrigation with
reclaimed water and participating in water exchange. Thus,
cities involved in water reclamation programmes are often
reluctant to charge farmers. On the other hand, farmers may
contribute to the costs of water transfer if they expect
significant income increases from reclaimed water application.
Cost sharing may help poorer municipalities to finance
the construction cost of wastewater treatment and reclamation
plants. It is suggested, and sometimes practised, to charge
the farmers with the current price of freshwater, so that its
replacement with reclaimed water will pay, provided the
price of the latter is lower. The revenue from water pricing
could be used as a further financial resource for funding
wastewater reuse projects (Abu-Madi et al. 2007).
To encourage farmers to join water exchange projects
reclaimed water may be provided to farmers at a discount, for
free or even by compensation (FAO 2007). When cities gain
from water exchange they may refrain from charging farmers
with the full cost of wastewater delivery. Ideally, the total
economic net benefit resulting from intersectoral water transfer
may be divided among the agricultural community and
cities. To find an agreement, structured negotiations appear to
be most appropriate. Water users such as industries, tourist
companies and golf courses, who benefit from the release of
freshwater, should also contribute to the costs of reclaimed
water.
Public funds can be crucial in those cases where water
reclamation and transfer projects would be economically
feasible but not affordable for the municipalities. At the
Llobregat River Delta, the water reclamation programme is
financially supported from national and EU funds (Age`ncia
Catalana de l’Aigua 2007).
As several studies showed, the cost of wastewater reuse
projects is often significantly lower than the cost of seawater
desalination, in terms of energy implications and greenhouse
gas emissions, and transmission of distant resources (Spulber
and Sabbaghi 1998). For instance, at Llobregat Delta the
average unitary cost of water exchange between agriculture
and cities can be approximated to 0.34 h/m3, whereas,
according to the literature, the unitary cost of seawater
desalination ranges between 0.45 and more than 1.0 h/m3
depending on the technique applied (FAO 2006). However, if
the volumes of freshwater that can be released are limited, sea
and brackish water desalination will become inevitable to
satisfy increasing water demands.
Authorities may require the use of reclaimed water as a
condition for granting or renewal of freshwater abstraction
rights (Asano et al. 2007). However, where it is needed to
motivate farmers to join intersectoral water transfer, such
policies will be probably counterproductive. There is a risk
that farmers face losses in productivity and income, especially
if the economic value added through reclaimed water use is
relatively small.
Governmental interventions that aim to find agreements
with farmers are advisable. The FAO suggested
recently the establishment of transparent methods to
negotiate allocation of water amongst competing uses
(FAO 2007). The economic benefits to be expected from
water exchanges must be demonstrated and the farmers
should be involved from the very beginning of water reclamation
programmes. Contracts can be based on temporary
trade of water between rural and urban sectors without
requiring the transfer of ownership of water abstraction
rights or, alternatively, on purchasing permanent entitlements
(Byrnes et al. 2008). If farmers request excessively
high rewards for releasing freshwater, they must anticipate
that no water trade would take place. Cities will undertake
other measures, such as developing and conveying remote
sources. If cities offer too small payments, farmers might not
participate depending on the economic value added due to
reclaimed water application in irrigation.
The range of freshwater price p to be paid to farmers may
be specified by the following simple formula:
rxRW/FW V/FWopouxFW þ rxRW/FW Q/FW ð2Þ
where
r: reclaimed water rate,
RW: reclaimed water volume per year,
FW: freshwater volume per year,
V: value added in agriculture (such as cost savings and
increases in yields),
u: unitary economic value of freshwater,
Q: total cost of water exchange.
1071 I. Heinz et al. 9 Water reclamation and intersectoral water transfer between agriculture and cities Water Science & Technology 9 63.5 9 2011
Then, it is to be considered that:
– The farmers face income increases if the revenue from
water trade plus the cost savings and soared crop sales
exceed the expenses from reclaimed water r RW.
– The farmers’ revenue from selling freshwater entitlements
to cities is p FW.
– The price p should ensure that farmers obtain income
increases.
– For cities, the price p for freshwater entitlements should
ensure that the compensation payments p FW to farmers
plus the total cost of water exchange Q do not exceed the
sum of the economic benefit of the released freshwater
u FW and the revenue r RW from charging farmers for
providing reclaimed water.
– As long as the price p is within the range as indicated in
Formula (2), wastewater reuse and intersectoral water
transfer will be beneficial for both farmers and cities
(win-win situation).
– As far as not covered by water pricing, the adverse and
beneficial environmental and health impacts should be
taken additionally into account.
CONCLUSIONS
As the illustrative example of Sant Feliu de Llobregat plant
near Barcelona in Spain shows, water reclamation can lead to
significant economic benefits in irrigated agriculture. Even
though these benefits are lower than the cost of water
reclamation, considerable economic benefits for the municipality
can be expected fromintersectoral water exchange. The
reason for that is the high economic value of freshwater
released for the urban water use in comparison with
the total cost of the water exchange. However, because the
water supply tariffs are often too low, there is a pervasive
underestimation of the benefits if they are used to express the
economic value of water.
Farmers face income increases due to the use of the
nutrient content of reclaimed water, less water abstraction
cost and additional sales revenues due to additional and
more reliable water supply. Lowering groundwater tables, falling
dry surface waters and impairment of ecosystems are
usually the consequences of overexploitation and discharging
effluents into the environment. Through application of treated
wastewater in irrigated agriculture and augmenting the urban
water supply by freshwater release such adverse impacts can be
reduced. Cities can avoid expenditures for digging deeper wells,
drinking water treatment and developing distant sources.
Cost recovery of municipal wastewater treatment and
reclamation plants and distribution networks is often not
guaranteed due to insufficient financial resources. Farmers
who benefit from wastewater reuse can contribute to the
costs. Charging farmers with the full cost of water reclamation
may discourage them from joining water exchange
projects. As the economic analysis of Sant Feliu de Llobregat
case proves, the added values that can be obtained from such
projects could allow even to compensate farmers, so that all
parties will gain (win-win situation).
Particularly in developing countries with limited financial
resources, the provision of funds from governments and debt
financing may be needed to implement reuse and water
exchange projects. Especially in regions with water scarcity,
investments in such projects usually pay back and are profitable
in the long term.
ACKNOWLEDGEMENTS
Thanks are expressed to the co-authors of the research project:
Prof. Miquel Salgot and Roberta Torricelli at the University of
Barcelona, Prof. Francesc Herna´ndez at the University of
Valencia, Spain, Dr. Jaime Collado at the Mexican Committee
for International Commission on Irrigation and Drainage,
Mexico City and Dr. Sasha Koo-Oshima at the FAO, who
gave substantial policy advice and funding to the project.
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reclamation and reuse project of El Prat de Llobregat, Barcelona,
Spain. In: Proceedings of the 6th IWA Specialist Conference on
Wastewater Reuse for Sustainability: Guiding the Growth of
Water Reuse, 9–12 October, Antwerp, Belgium.
Segui, L., Cabrera, L. & Alfranca, O. 2008 In: Water reuse. An international
survey of current practice, issues and needs. Jime´nez, B. &
Asano, T. (eds). IWA Publishing, London.
Spulber, N. & Sabbaghi, A. 1998. Economics of Water Resources: From
Regulation to Privatization. Boston/London/Dordrecht.
WFD 2000 Water Framework Directive. Directive 2000/60/EC. Brussels,
Belgium.
WHO-FAO-UNEP 2006 Guidelines for the safe use of wastewater,
excreta and greywater. Volume II: Wastewater use in agriculture,
Geneva. Switzerland.
1073 I. Heinz et al. 9 Water reclamation and intersectoral water transfer between agriculture and cities Water Science & Technology 9 63.5 9 2011
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Heinz, I, Salgon, M. & Koo-Oshima, S. (20110. Water reclamation and intersectoral water transfer
between agriculture and cities - a FAO economic wastewater study. Water Science, & Technology,
63(5), pp.1067-1073. Retrieved July 6, 2011 from LexisNexis Academic.
ABSTRACT
Cost–benefit studies on replacing conventional agricultural water resources with reclaimed water
in favour of cities are still rare. Some results of a study under auspices of the Food and
Agriculture Organisation (FAO) are presented. By means of an illustrative example at Lobregat
River basin in Spain, it could be proved that reclaimed water reuse and intersectoral water
transfer can result in economic and environmental benefits at the watershed level. The
agricultural community faces cost savings in water pumping and fertilising, increases in yields and
incomes; the municipality benefits from additional water resources released by farmers. Farmers
should be encouraged to participate by implementing adequate economic incentives. Charging
farmers with the full cost of water reclamation may discourage farmers from joining water
exchange projects. Particularly in regions with water scarcity, investments in reclaimed water
reuse and water exchange arrangements usually pay back and are profitable in the long term.
Key words 9 cost–benefit analysis, intersectoral water transfer, irrigated agriculture, municipal
water supply, wastewater reuse, water exchange, water reclamation
INTRODUCTION
In arid and semi-arid regions, treated wastewater (reclaimed
water) reuse is an effective measure to tackle water scarcity
problems. This applies particularly to countries where irrigated
agriculture, usually the biggest water user, plays a major
role in the economy. It is also of note that in most cases
treated and untreated wastewater is still being discharged into
rivers causing adverse environmental and even health
impacts. Certainly, there are many regions where reclaimed
water reuse is already practised for irrigation and other
purposes. Irrigation with reclaimed water helps to grow
more food and preserve water resources. It is quoted that at
least 10% of the world’s population is thought to consume
food produced by irrigation with wastewater (WHOFAO-
UNEP 2006). In southern countries of Europe, 2% of
the total treated effluents are reused after reclamation, mainly
for agricultural irrigation. In the Mediterranean Region, reuse
is increasing at a rate of 25% per year (Jime´nez & Asano
2008). In Spain, Lazarova & Bahri (2008) claim that 22% of
the collected wastewater is reused in agriculture. With
increasing water scarcity and growing populations, the
importance of water reclamation and reuse will rise. In
addition, our thesis is that scarcity problems in cities can be
mitigated by intersectoral transfer of freshwater replaced by
farmers who use treated wastewater with economic benefits
both for farmers and the society.
Wastewater treatment and reuse projects require effective
technical infrastructures and economically efficient and
socially acceptable solutions: reuse projects must be financially
feasible and affordable. An economic framework
including assessment criteria is barely needed for the evaluation
of economic and financial feasibility of wastewater reuse
projects (Asano et al. 2007).
Numerous publications in the field of wastewater reuse
technologies exist. Many applications worldwide are
described in Jime´nez & Asano (2008). One example can be
found in Virginia, South Australia, where the effluents from
Ingo Heinz (corresponding author)
Ex-University Dortmund,
Germany,
E-mail Ingo.Heinz@uni-dortmund.de
Miquel Salgot
University of Barcelona,
Spain,
E-mail salgot@ub.edu
Sasha Koo-Oshima
Food and Agriculture Organisation of
the United Nations,
Rome,
E-mail Koo-Oshima.Sasha@epa.gov
doi: 10.2166/wst.2011.292
1067 & IWA Publishing 2011 Water Science & Technology 9 63.5 9 2011
the Bolivar wastewater treatment plant in Adelaide are
transferred to the Virginia area, north of Adelaide, for irrigation
of horticultural crops. The water reclamation plant
incorporates dissolved air flotation and filtration processes.
Apart from it, measures to increase the amount of reclaimed
water available such as the development of an aquifer storage
and recovery system have been investigated (Marks et al.
2002). In the US, agricultural irrigation is the biggest water
reuse activity. In the State of California, 46% of the total
volume of reclaimed water is used for this purpose (California
StateWater Resources Control Board 2002). For example, the
city of Santa Rosa treats to a tertiary level the effluents of five
different cities in the Sonoma County. More than half of the
water produced is used to irrigate approximately 2,310 ha of
farmlands. During the winter months when there is no
demand for irrigation, the effluent is used to recharge an
aquifer and produce electricity using the energy from geysers
(California Energy Commission 2002; Asano et al. 2007).
Some economic analyses of wastewater reuse for different
purposes, such as agricultural and landscape irrigation, industrial
applications and potable reuse, can be found. They
address both the costs and the benefits of water reclamation
(Aquarec 2006a, b; Asano et al. 2007). Farmers who convert
to reclaimed water can lower their expenses on irrigation if
the cost of reclaimed water is cheaper than that of conventional
sources. Additional economic benefits can occur
thanks to the improved availability of reclaimed water,
which may allow increases in yields and sales revenues;
especially in water shortage periods, farmers can prevent
losses.
Moreover, farmers can release conventional water for
cities by replacing it with reclaimed water generated by those
or other cities. Such a water exchange (or intersectoral water
transfer) can result in manifold benefits for municipalities,
such as cost savings in water extraction, water delivery,
water resources development, drinking water treatment, and
removal of nutrients in wastewater treatment (Segui et al.
2008). Further benefits may include improvements in the
economic development of urban areas due to increased
water availability (e.g. industries, tourism). Beneficial impacts
on nature on water bodies and aquatic habitats can result from
reduced overexploitation of aquifers, rivers and lakes, from less
wastewater discharges and from prevented seawater intrusion
(Mujeriego et al. 2007). However, not all of those impacts can
be simply evaluated in economic terms (Aquarec 2006b).
On the other hand, environmental and health risks can
decrease the benefits if the prescribed legal requirements
for reclaimed water quality and application are not met.
Wastewater reuse for irrigation is practised worldwide,
often without any treatment or with a combination of
only partial treatment, sometimes without wearing personal
protective equipment (shoes, gloves) or washing of
produce to protect consumers of raw vegetables (WHOFAO-
UNEP 2006; Asano et al. 2007). The biggest irrigated
area using untreated wastewater in the world is located in
Mexico, D.F., where the majority of this water is reused for
agricultural irrigation (Jime´nez 2008a). In the area presently
receiving wastewater, the Mezquital Valley (named
also Tula Valley), a century ago agriculture could not be
developed due to the lack of water. Currently, around
74,000 farmers irrigate 76,000 ha using mainly the wastewater
from Mexico City. Wastewater with organic matter
and nutrients for plants is greatly appreciated by the
farmers. Due to its fertilising content, leasing prices of
wastewater irrigated agricultural land increased by a
factor of nearly three compared with rain-fed agricultural
land, and it is further possible to grow two or three crops
per year instead of just one. The disadvantage is the
potential negative effects on health: a 16-fold increase in
morbidity by helminths in children in comparison to
unexposed nearby areas has been reported (Jime´nez
2008b). Even though there exists a self-purifying capacity
of water (flowing in pipelines, channels, and streams and
through the soil, as well as when it is stored in impoundments),
it is not enough to reach good quality for irrigation
without hazards. Additional treatment plants are being
planned to treat Mexico City wastewater, which will
improve the sanitary conditions in the area and will
increase the cost of water supply.
As cost–benefit studies on intersectoral water exchange
are still rare, some of the results of a research project, funded
by the Food and Agriculture Organisation (FAO), will be
presented (Heinz et al. 2008). In this research project, eight
case studies were carried out in Spain and Mexico. One of
them, located at the Llobregat River Delta in Spain, will be
used as an illustrative example.
MATERIALS AND METHODS
The Llobregat River Basin is situated in the North-East of
Spain close to the city of Barcelona. During the last decades,
the river Llobregat has been highly polluted by industrial and
urban wastewaters and experiences periodic floods and
droughts. Overexploitation, and furthermore the occurrence
of natural salt formations and the corresponding mining
exploitations in the upper basin, are causing an increase
in the water salinity and consequently salinisation of the
1068 I. Heinz et al. 9 Water reclamation and intersectoral water transfer between agriculture and cities Water Science & Technology 9 63.5 9 2011
aquifers. Since 1991, a comprehensive programme of wastewater
treatment plants has been implemented along the
Llobregat River Basin. A water reclamation programme has
been planned and in part already implemented (Age`ncia
Catalania de l’Aigua 2007). In the considered area, there are
two main wastewater treatment plants: the Sant Feliu de
Llobregat plant and the Prat de Llobregat plant, both with
tertiary treatment. Especially the latter plant – with a wastewater
generation of around 120 Mm3/yr one of the biggest
treatment plants in Europe – is typically a multi-purpose
project that aims also to recharge aquifers, improving the
stream flow and quality of the river, irrigating wetlands and
preventing seawater intrusion with the adequately treated
effluents.
In the following, the first plant has been selected as an
example to show the potential economic efficiency of the
water reclamation and intersectoral water transfer. The effluent
from this plant of 19 Mm3/yr could be used for irrigation
purposes in an agricultural area of more than 600 ha, with
mainly herbaceous crops. The existing tertiary treatment
consisted only of sand filter and disinfection, and only a
few farmers use this water due to its high conductivity of
2.95 dS/m on average. Due to the high salinity of the effluent
the farmers mix it with well water. The farmers prefer to use
the aquifer and the Llobregat river water as the main
resources. In drought periods, however, the farmers have to
use it compulsorily to a greater extent. Normally, the permission
to use water from the Lobregat river is 1.5 m3/s. In water
shortage periods, however, the use is reduced to 0.8 m3/s. In
order to make the tertiary effluents more acceptable for the
farmers the conductivity must be reduced by upgrading the
treatment plant.
Furthermore, the Catalonian Water Agency (ACA)
initiated the construction of a seawater desalination plant
with a capacity of 60 Mm3/yr in order to augment the water
availability for the municipality of Barcelona.
In order to assess the economic efficiency of the wastewater
reuse the cost and benefits must be compared. The cost
components include the capital cost, the operation and
maintenance costs of the upgraded tertiary wastewater treatment
and the cost of conveying the reclaimed water to the
fields. The economic benefits for the farmers include not only
the cost savings in water pumping (e.g. groundwater) and in
fertilising (due to the nutrient content of reclaimed water) but
also increases in yields. A surplus of the economic benefit
above the cost can lead to additional income of farmers.
However, the actual income increase depends on how much
they have to pay for the reclaimed water. If the cost exceeds
the benefit, the water reclamation project would not be
economically efficient, unless there are further beneficial
impacts. As mentioned already, they can result from the
water exchange between cities and farmers, who replace
freshwater with treated wastewater.
The economic efficiency of such a water exchange
depends on the costs of extraction, storage and conveyance
of freshwater to the cities and on the cost savings in municipal
water services in the entire area of influence, such as
reduced expenses in groundwater abstraction, in drinking
water treatment due to reduced pollution of rivers and in
water resource development.
Another methodological approach refers to the economic
value of the increased municipal water supply. This approach
does not differ substantially from the first one. The water
value indicates both the cost of and the willingness to pay for
obtaining additional water. If FW is the freshwater released
and u the unitary (marginal) value of water, the economic
benefit of water transfer H to cities can be computed by
H ¼ FW u ð1Þ
The water value u is naturally influenced by the costs of
water infrastructures (mainly supply and sanitation). The
value can change in the course of time. It may rise due to
growing cost of intersectoral water transfer or it may decrease
due to the water user’s reduced willingness to pay as a
consequence of the increased urban water supply. In the
long term, u rises with increasing water scarcity if precipitation
diminishes or water demand is growing. Scarcity costs
may be interpreted as scarcity rents that emerge wherever the
water availability does not satisfy water demands (Heinz et al.
2007); they reflect the costs needed to reduce the water
shortage in the future.
RESULTS AND DISCUSSION
The investment cost of upgrading the tertiary treatment at the
Sant Feliu de Llobregat plant to make the effluent better
suitable for agricultural irrigation, plus the cost of a pipeline
network, amounts to 1.112 Mh. Pumping the effluent to the
fields would cost 208,390 h/yr. As Table 1 shows, the total
cost of water reclamation (column 5) exceeds the total added
value for farmers (column 4). So, this wastewater reuse
project would not be economically efficient in the mentioned
circumstances. However, the question arises whether there
are further benefits resulting from intersectoral water transfer.
Even in such a case the farmers will reject converting to
1069 I. Heinz et al. 9 Water reclamation and intersectoral water transfer between agriculture and cities Water Science & Technology 9 63.5 9 2011
reclaimed water if they would have to pay the full cost. In
contrast, as Table 1 indicates, they would be better off if they
were charged in part, such as with the conveyance cost
only, resulting to an income increase of around 253,000 h/
yr. The question remains whether this is a sufficient economic
incentive to use reclaimed water instead of conventional
resources.
Table 2 shows the results of the cost–benefit analysis for
the same wastewater reuse project as described above, but
modified by the consideration of intersectoral water transfer.
At this example, the current domestic water price of 1.11 h/m3
in the research area is used as a lower estimate of the
economic value of the released freshwater. To some extent
this price contains infrastructure, scarcity and environmental
costs. Water users in Catalonia are charged a special tax
(around 26% of the domestic water price) in order to guarantee
the long-term water supply of towns and to improve the
quality of both surface and groundwater (Age`ncia Catalana
de l’Aigua 2007).
In contrast to the results shown in Table 1, wastewater
reuse in agriculture becomes economically efficient as the
benefits of the city are additionally regarded. The added value
or economic net-benefit of water exchange between agriculture
and municipality can be estimated to be more than
6.9 Mh/yr (Table 2).
As mentioned, environmental costs and benefits and
other impacts should be considered as well; however, they
are difficult to monetarise. In literature, many approaches can
be found to evaluate such so-called ‘‘intangible’’ impacts or
‘‘externalities’’ (Griffin 2006; Aquarec 2006a). In principle, the
externalities can be evaluated by expressing the importance
people give to the impacts concerned (such as the value of
wetlands irrigated by wastewater). The usual approach is to
explore the willingness of people or communities to bear the
cost of obtaining the benefits or of preventing adverse
impacts. If impacts cannot be monetarised easily or not at
all (e.g. certain health risks) they should be taken into
account by using physical impact measures.
The unitary cost of water exchange of around 0.22 h/m3
may be compared with the domestic water price of 1.11 h/m3
as a lower estimate of the water value. Obviously, there is a
big gap between this cost and the willingness to pay for water.
This difference indicates a lower estimate of the unitary
benefit added for the citizens. Water exchange between
farmers and the city would provide additional water for
high-valued purposes at considerably lower cost. In terms
of cost–benefit analysis, an expansion of the intersectoral
water transfer could be worthwhile until a maximum net
benefit might be achieved. However, constraints such as the
limited availability of freshwater used by farmers and financial
barriers must be taken into account.
Water prices should cover both the infrastructure and the
scarcity costs as far as possible. In reality, this is not the usual
case for political reasons (for instance, due to low income of
poor families). There are many examples where even the
infrastructure costs are not fully recovered by water prices,
Table 1 9 Costs related to water reuse – an example in the Llobregat River Delta, Spain
Cost savings in water pumping
(1,000 h/yr)
Cost savings in fertilising
(1,000 h/yr)
Increase in sales revenue
(1,000 h/yr)
Added value in agriculture*
(1,000 h/yr)
Cost of reclaimed water**
(1,000 h/yr)
62.6 10.4 388.1 461.1 798.2
*The added value includes the cost savings in water pumping and fertilising and the increase in sales revenue.
**The total cost of reclaimed water of 798,216 h/yr includes the annual capital cost of 77,384 h/yr and 512,442 h/yr, the operation and maintenance cost of wastewater treatment, plus
the cost of conveying the reclaimed water to the fields of 208,390 h/yr. The annual capital costs are computed by multiplying 1.122 Mh, the investment costs of the new tertiary treatment
plant and pipeline network, with the capital recovery factor of 0.06897 (average service time 35 years and rate of interest 6%).
Table 2 9 Net benefits of intersectoral water transfer – an example
Cost of water exchange*
(1,000 h/yr)
Value added in agriculture
(1,000 h/yr)
Economic value of improved water availability for the city**
(1,000 h/yr)
Net benefit of water exchange
(1,000 h/yr)***
1,608.9 461.1 8,103 6,979.8
*The total cost of water exchange of 1,608,916 h/yr includes 798,216 h/yr, the total annual cost of the reclaimed water (Table 1) plus 810,700 h/yr, the extraction and conveyance cost of
freshwater. No capital cost of the latter is considered as it is assumed that the existing infrastructure is sufficient to extract and distribute the released water to the city. The unitary cost
of water exchange is around 0.22 h/m3, i.e. 1.6 Mh/yr divided by approximately 7.3 Mm3/yr, the water volume exchanged.
**The freshwater release of approximately 7.3 Mm3/yr multiplied with the domestic water price of 1.11 h/m3 renders a lower estimate for the economic benefit of 8.103 Mh/yr.
***The net benefit of water exchange is the sum of the value added in agriculture of 461,100 h/yr and the economic value of improved water availability for the city of 8,103,000 h/yr
minus the total cost of water exchange of around 1,608,900 h/yr (column 1).
1070 I. Heinz et al. 9 Water reclamation and intersectoral water transfer between agriculture and cities Water Science & Technology 9 63.5 9 2011
like in Catalonia, Spain (Age`ncia Catalana de l’Aigua 2007).
Ideally, water prices should cover also the environmental
costs associated with the provision of municipal water services;
however, they are often ignored. The European Water
Framework Directive (WFD) commits the Member States to
take into account the principle of cost recovery (WFD 2000).
However, it should be taken into account that pricing is not
the only financing instrument to achieve cost recovery. Apart
from water tariffs, cost recovery can be ensured also by
subsidies provided by governments or by transfers from
international organisations. But in order to assess the economic
efficiency of intersectoral water transfer projects, u
should reflect the true value of water as far as possible.
Charging farmers with the full cost of water reclamation
can discourage them from converting to irrigation with
reclaimed water and participating in water exchange. Thus,
cities involved in water reclamation programmes are often
reluctant to charge farmers. On the other hand, farmers may
contribute to the costs of water transfer if they expect
significant income increases from reclaimed water application.
Cost sharing may help poorer municipalities to finance
the construction cost of wastewater treatment and reclamation
plants. It is suggested, and sometimes practised, to charge
the farmers with the current price of freshwater, so that its
replacement with reclaimed water will pay, provided the
price of the latter is lower. The revenue from water pricing
could be used as a further financial resource for funding
wastewater reuse projects (Abu-Madi et al. 2007).
To encourage farmers to join water exchange projects
reclaimed water may be provided to farmers at a discount, for
free or even by compensation (FAO 2007). When cities gain
from water exchange they may refrain from charging farmers
with the full cost of wastewater delivery. Ideally, the total
economic net benefit resulting from intersectoral water transfer
may be divided among the agricultural community and
cities. To find an agreement, structured negotiations appear to
be most appropriate. Water users such as industries, tourist
companies and golf courses, who benefit from the release of
freshwater, should also contribute to the costs of reclaimed
water.
Public funds can be crucial in those cases where water
reclamation and transfer projects would be economically
feasible but not affordable for the municipalities. At the
Llobregat River Delta, the water reclamation programme is
financially supported from national and EU funds (Age`ncia
Catalana de l’Aigua 2007).
As several studies showed, the cost of wastewater reuse
projects is often significantly lower than the cost of seawater
desalination, in terms of energy implications and greenhouse
gas emissions, and transmission of distant resources (Spulber
and Sabbaghi 1998). For instance, at Llobregat Delta the
average unitary cost of water exchange between agriculture
and cities can be approximated to 0.34 h/m3, whereas,
according to the literature, the unitary cost of seawater
desalination ranges between 0.45 and more than 1.0 h/m3
depending on the technique applied (FAO 2006). However, if
the volumes of freshwater that can be released are limited, sea
and brackish water desalination will become inevitable to
satisfy increasing water demands.
Authorities may require the use of reclaimed water as a
condition for granting or renewal of freshwater abstraction
rights (Asano et al. 2007). However, where it is needed to
motivate farmers to join intersectoral water transfer, such
policies will be probably counterproductive. There is a risk
that farmers face losses in productivity and income, especially
if the economic value added through reclaimed water use is
relatively small.
Governmental interventions that aim to find agreements
with farmers are advisable. The FAO suggested
recently the establishment of transparent methods to
negotiate allocation of water amongst competing uses
(FAO 2007). The economic benefits to be expected from
water exchanges must be demonstrated and the farmers
should be involved from the very beginning of water reclamation
programmes. Contracts can be based on temporary
trade of water between rural and urban sectors without
requiring the transfer of ownership of water abstraction
rights or, alternatively, on purchasing permanent entitlements
(Byrnes et al. 2008). If farmers request excessively
high rewards for releasing freshwater, they must anticipate
that no water trade would take place. Cities will undertake
other measures, such as developing and conveying remote
sources. If cities offer too small payments, farmers might not
participate depending on the economic value added due to
reclaimed water application in irrigation.
The range of freshwater price p to be paid to farmers may
be specified by the following simple formula:
rxRW/FW V/FWopouxFW þ rxRW/FW Q/FW ð2Þ
where
r: reclaimed water rate,
RW: reclaimed water volume per year,
FW: freshwater volume per year,
V: value added in agriculture (such as cost savings and
increases in yields),
u: unitary economic value of freshwater,
Q: total cost of water exchange.
1071 I. Heinz et al. 9 Water reclamation and intersectoral water transfer between agriculture and cities Water Science & Technology 9 63.5 9 2011
Then, it is to be considered that:
– The farmers face income increases if the revenue from
water trade plus the cost savings and soared crop sales
exceed the expenses from reclaimed water r RW.
– The farmers’ revenue from selling freshwater entitlements
to cities is p FW.
– The price p should ensure that farmers obtain income
increases.
– For cities, the price p for freshwater entitlements should
ensure that the compensation payments p FW to farmers
plus the total cost of water exchange Q do not exceed the
sum of the economic benefit of the released freshwater
u FW and the revenue r RW from charging farmers for
providing reclaimed water.
– As long as the price p is within the range as indicated in
Formula (2), wastewater reuse and intersectoral water
transfer will be beneficial for both farmers and cities
(win-win situation).
– As far as not covered by water pricing, the adverse and
beneficial environmental and health impacts should be
taken additionally into account.
CONCLUSIONS
As the illustrative example of Sant Feliu de Llobregat plant
near Barcelona in Spain shows, water reclamation can lead to
significant economic benefits in irrigated agriculture. Even
though these benefits are lower than the cost of water
reclamation, considerable economic benefits for the municipality
can be expected fromintersectoral water exchange. The
reason for that is the high economic value of freshwater
released for the urban water use in comparison with
the total cost of the water exchange. However, because the
water supply tariffs are often too low, there is a pervasive
underestimation of the benefits if they are used to express the
economic value of water.
Farmers face income increases due to the use of the
nutrient content of reclaimed water, less water abstraction
cost and additional sales revenues due to additional and
more reliable water supply. Lowering groundwater tables, falling
dry surface waters and impairment of ecosystems are
usually the consequences of overexploitation and discharging
effluents into the environment. Through application of treated
wastewater in irrigated agriculture and augmenting the urban
water supply by freshwater release such adverse impacts can be
reduced. Cities can avoid expenditures for digging deeper wells,
drinking water treatment and developing distant sources.
Cost recovery of municipal wastewater treatment and
reclamation plants and distribution networks is often not
guaranteed due to insufficient financial resources. Farmers
who benefit from wastewater reuse can contribute to the
costs. Charging farmers with the full cost of water reclamation
may discourage them from joining water exchange
projects. As the economic analysis of Sant Feliu de Llobregat
case proves, the added values that can be obtained from such
projects could allow even to compensate farmers, so that all
parties will gain (win-win situation).
Particularly in developing countries with limited financial
resources, the provision of funds from governments and debt
financing may be needed to implement reuse and water
exchange projects. Especially in regions with water scarcity,
investments in such projects usually pay back and are profitable
in the long term.
ACKNOWLEDGEMENTS
Thanks are expressed to the co-authors of the research project:
Prof. Miquel Salgot and Roberta Torricelli at the University of
Barcelona, Prof. Francesc Herna´ndez at the University of
Valencia, Spain, Dr. Jaime Collado at the Mexican Committee
for International Commission on Irrigation and Drainage,
Mexico City and Dr. Sasha Koo-Oshima at the FAO, who
gave substantial policy advice and funding to the project.
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