Investing in Water for Food, Ecosystems and Livelihoods

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    Investing in Water for Food,

    Ecosystems and Livelihoods

    Comprehensive Assessment of Water Management in Agriculture

    BLUE PAPER

    Stockholm 2004

    Discussion Draft

    byDavid Molden and Charlotte de Fraiture

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    Through a process of research synthesis, review, and dialogue, the Assessment is bringing together

    scientists from over 90 institutes worldwide with policymakers, development professionals, and water

    users. The results of this process will enable farming communities, governments and donors to make

    better-quality water decisions in the near future and over the next 25 years.

    The authors are David Molden, Coordinator of the Comprehensive Assessment, and Charlotte de

    Fraiture, Principal Researcher, International Water Management Institute. Sarah Carriger, Science

    Communication Specialist, formerly of the International Water Management Institute, edited andredrafted the paper.

    The paper has not been accepted or appoved by the Comprehensive Assessment process. It is intended

    to present issues dealt with by the Comprehensive Assessment to open up discussion around these.

    Please send your comments to the email address given below.

    Partners:

    The Comprehensive Assessment is an initiative of the Consultative Group on International

    Agricultural Research (CGIAR), convened by the International Water Management Institute (IWMI).

    It is made possible through support from the governments of Netherlands, Switzerland, Sweden,

    Taiwan, Japan and Austria; FAO, the OPEC fund, the Rockefeller Foundation.

    New partners are welcome. More information about how you and your organization can participate in

    the Assessment process is available on our website or you can contact us at the address given below.

    Mailing Address: PO Box 2075, Colombo, Sri Lanka

    Tel. : 94-11-2787404, 2784080

    Fax. : 94-11-2786854

    E-mail : comp.assessment@cgiar.org

    Website: http://www.iwmi.org/assessment

    The Comprehensive Assessment of Water Management in Agriculture takes stock of

    the costs, benefits, and impacts of the past 50 years of water development for agriculture,

    the water management challenges communities are facing today, and teh solutions people

    have developed. The results of the Assessment will enable farming communities,

    governments and donors to make better-quality investment and management decisions

    in the near future and over the next 25 years.

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    DISCUSSION DRAFT: AUGUST, 2004

    Investing in Water for Food,

    Ecosystems and Livelihoods

    Sustainably meeting the food and livelihood needs of a growing population will require some very

    difficult choices about how water is developed and managed in the next 25 years. More food will

    be necessary, and more food translates into more water for agriculture. More water for agriculture

    will in many cases mean less for the environment. So how do you manage water for food and the

    environment? And how do you do so in a way that also reduces poverty?

    In the following pages we review several policy and water investment optionsalong with

    their livelihood and environmental implications. This paper presents issues being addressed by the

    Comprehensive Assessment of Water Management in Agriculture, an international research program

    that brings together scientists, development professionals and stakeholders from around the world.

    This is the first time science has been focused at this level and intensity on answering questions

    related to water, agriculture, poverty and environmental conservation.

    The Assessment is at the mid-way mark and wont be complete until 2006, but already wehave evidence to suggest which approaches are the most promising. Our intention in sharing these

    preliminary findings is to raise awareness that water in agriculture is a pressing issue, that business

    as usual is not an option, and that there are potential solutions, but they are not necessarily the

    ones that have received the most attention.

    How much water do we need to feed people?

    By 2025, there will be an estimated 2 billion more people to feed. Growing more food means using

    more water. To produce one kilogram of grain, plants must transform between 500 and 4000 liters

    of waterdepending on the type of crop, the climate, and water and land management practices

    into vapor through the process of evapotranspiration (ET) (see table 1).

    Table 1. The amount of water used to grow food (in liters evapotranspired per kilogram).

    USA France China India Japan World

    Wheat a 1,390 660 1,280 2,560 1,350 1,790

    Rice a 1,920 1,270 1,370 3,700 1,350 2,380

    Maize a 670 610 1,190 4,350 1,390

    Beef b 10,060 7,740 12,600 14,379 9,540 9,680

    Pork b 3,370 1,940 2,520 7,560 4,080 3,680

    Onions c 140Tomatoes c 130

    afrom Fraiture et al (2004) bChapagain and Hoekstra (2003) cRenault and Wallender (2000); data for California

    Depending on their diet and where their food is grown, each person is responsible for the conversion of 2000

    to 5000 liters of liquid water to vapor each day. The daily amount of water we drink (2 to 5 liters) and use for

    washing, sanitation, and other household tasks (50 to 200 liters per person) seems insignificant when compared

    to the amount of water we eat.

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    Box 1. How much irrigation do we need? Current best guesses.

    In preparation for the second World Water Forum, groups of researchers forecast how

    much more water would be needed in the year 2025. The amount of additional water withdrawn

    from rivers for irrigation ranged from 24% to values less than zero. The difference in forecasted

    values reflect different ideas about how water should or could be used in the future (box 1).

    Considering both rainfed and irrigated agriculture, Rockstrm et al (1999) estimated that the

    amount of water consumed by agricultural ET would have to increase from 6,100 km3 to 9,700

    km3, given current trends in population growth, improvements in living standards and water use

    patterns. This is an enormous quantity of water that has to be converted to evaporation for food

    production unless we change the way business is done.

    How much more water, where it comes from, and the environmental consequences of its

    use, depend very much on choices made in the next few years. To a large extent, how much

    additional water will need to be withdrawn from rivers depends on how much more food it is

    possible to grow on existing rain-fed and irrigated lands. The Comprehensive Assessment will be

    able to provide a good estimate of rain-fed and irrigated potential and tools to explore different

    scenarios. But in making decisions about where to focus resources, it is important to consider not

    just production potential, but also poverty reduction potential.

    Projected increases in water withdrawals for irrigation (in km3).

    Source Total irrigation withdrawals

    1995 2025 Increase 1995-2025

    Shiklomanov 2,488 3,097 24%

    IWMI 2,469 2,915 18%

    FAO** 2,128 2,420 14%

    IFPRI 4%*

    **IFPRI number represents projected increase in irrigation depletion, not in irrigation withdrawals.**FAO uses 2030 as projection year.

    Researchers from several leading organizations have explored what they consider to be business asusual or base scenarios of future water supply and demand. Looking at the table below you can seethat under all four scenarios, irrigation withdrawals increase by 2025but with significant differencesin by how much.

    Shiklomanovs projection (2000) considers present trends and extrapolates them into thefuture. The IWMI base case (Seckler et al 2000) projects increases in efficiency and productivity inirrigation, but is pessimistic about the amount of gains from purely rain-fed agriculture (without anysupplemental irrigation). It also assumes that most countries will opt for food self-sufficiency ratherthan rely on trade. The FAO scenario (2002) is slightly more optimistic about gains in rain-fedareas, and thus predicts less need for irrigation. The IFPRI scenario (Rosegrant et al, 2002) is veryoptimistic about gains in rain-fed areas, particularly in developed countries, and assumes thatglobal food trade will form a significant part of the solution.

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    The water and poverty connection

    The majority of people living in developing countries still depend on agriculture for their livelihoods.

    Approximately 70 percent of the worlds poor live in rural areas with limited livelihood opportunities

    outside of agriculture (World Bank 2004b). Providing these people with a reliable source of water

    whether its from small-scale water harvesting or large-scale irrigationmakes it possible for

    them to move beyond subsistence farming. It prevents yield losses due to short-term drought,

    which in sub-Saharan Africa may claim one out of every five harvests. It gives farmers the water

    security they need to risk investing in other productivity-enhancing inputs, such as fertilizers and

    high-yielding varieties. And it enables them to grow higher-value crops, such as vegetables, whic