Basic Water Requirements for Human Activities: Meeting Basic Needs by Peter H. Gleick, M. IWRA Pacific Institute for Studies in Development. Environment, and Security t204 Preservation Park Way OAKLAND CA 94612 U.S-4. JZibrary IRC International Water and Sanitation Centre Tel.: +31 70 30 689 80 Fax; +31 70 38 089 64 E-mail: [email protected]271.0 96BA INTRODUCTION The last few years have seen a remarkable change in the nature of the global discussion of issues of environment ap/1 development. In the work of the Brundtland Com- ion [1], the extensive lead-up to the 1992 Earth Summit in Brazil, and in subsequent discussions and work, the intimate connections between environment and development have been accepted as a given. The questions now being discussed and researched are bow to define and achieve development in a "sustainable" way. This is a much needed and welcome change. Unfortunately, considerable debate and confusion sur- round both the terms "sustainable'* and "development" and only modest forward progress has been made. This lack of progress is particularly disturbing in the area of water resources, which are vitally important for producing food, maintaining aquatic ecosystems, and protecting human health. Among the concepts raised nearly 20 years ago during :he 1977 Mar del Plata conference — one of the earliest international efforts to address global water problems — was that of "basic needs" [2]: " all peoples, whatever their stage of development _^d their social and economic conditions, have the right to have access to drinking water in quantities and of a quality equal to their basic needs. This concept was strongly reaffirmed during the 1992 Earth Summit in Rio de Janeiro and expanded to include ecological water needs [3]: In developing and using water resources, priority has to be given to the satisfaction of basic needs and the safeguarding of ecosystems. Implicit in this phrase is the idea of minimum resource rsquirements for certain human and ecological functions, ind the allocation of sufficient resources to meet those seeds. This article defines and quantifies "basic water requirements'* (BWRs) in terms of quantity and quality :br four basic human needs: drinking water for survival. water for human hygiene, water for sanitation services, and modest household needs for preparing food. The concept of identifying water needs for growing food and protecting natural ecosystems is also briefly discussed. These minima) needs are also d'sc^s^i in the context of international water law and two regions with a long history of water disputes: the Middle East and California. Finally, data are presented showing the current failure of many nations to provide even this basic level of clean water to their citizens. Based on the analysis here, I recommend that inter- national organizations, national and local governments, and water providers adopt a basic water requirement standard for human needs of 50 liters per person per day (I/p/d) and guarantee access to it independently of an individual's economic, social, or political status. Unless this basic need is met, large-scale human misery and suffering will continue and grow in the future, contributing to the risk of social and military conflict. Ultimately, decisions about defining and applying a basic water re- quirement will depend on political and institutional fac- . tors, but the concept may prove useful in meeting basic water needs for the next century. DEFINING BASIC WATER REQUIREMENTS Different sectors of society use water for different pur- poses: drinking, removing, or diluting wastes, producing manufactured goods, growing food, producing and using energy, and so on. The water required for each of these activities varies with climatic conditions, lifestyle, culture, tradition, diet, technology, and wealth, as shown over 20 years ago in the groundbreaking work of White, Bradley, and White [4]. The type of access to water alone is an important determinant in total water use. Tables 1 and 2 show that the level of domestic water use varies with distance from the water source and with the climate. The term "water use" encompasses many different ideas :25O-S060/96/S3J0 Water International 21 (1996) 8J-92 rWRA/Priated in the U.S.A. LIBRARY IRC PO Box 93190, 2509 AD THE HAGUE Tel.: +31 70 30 689 80 Fax: +31 70 35 899 64 BARCODE: /<//?*} LO:
Transcript
Basic Water Requirements for Human Activities:Meeting Basic Needs
by Peter H. Gleick, M. IWRAPacific Institute for Studies in Development. Environment, and Securityt204 Preservation Park WayOAKLAND CA 94612U.S-4.
The last few years have seen a remarkable change inthe nature of the global discussion of issues of environmentap/1 development. In the work of the Brundtland Com-
ion [1], the extensive lead-up to the 1992 EarthSummit in Brazil, and in subsequent discussions andwork, the intimate connections between environment anddevelopment have been accepted as a given. The questionsnow being discussed and researched are bow to defineand achieve development in a "sustainable" way. This isa much needed and welcome change.
Unfortunately, considerable debate and confusion sur-round both the terms "sustainable'* and "development"and only modest forward progress has been made. Thislack of progress is particularly disturbing in the area ofwater resources, which are vitally important for producingfood, maintaining aquatic ecosystems, and protectinghuman health.
Among the concepts raised nearly 20 years ago during:he 1977 Mar del Plata conference — one of the earliestinternational efforts to address global water problems —was that of "basic needs" [2]:
" all peoples, whatever their stage of development_^d their social and economic conditions, have theright to have access to drinking water in quantities andof a quality equal to their basic needs.
This concept was strongly reaffirmed during the 1992Earth Summit in Rio de Janeiro and expanded to includeecological water needs [3]:
In developing and using water resources, priority hasto be given to the satisfaction of basic needs and thesafeguarding of ecosystems.Implicit in this phrase is the idea of minimum resource
rsquirements for certain human and ecological functions,ind the allocation of sufficient resources to meet thoseseeds. This article defines and quantifies "basic waterrequirements'* (BWRs) in terms of quantity and quality:br four basic human needs: drinking water for survival.
water for human hygiene, water for sanitation services,and modest household needs for preparing food. Theconcept of identifying water needs for growing food andprotecting natural ecosystems is also briefly discussed.These minima) needs are also d'sc^s^i in the context ofinternational water law and two regions with a long historyof water disputes: the Middle East and California. Finally,data are presented showing the current failure of manynations to provide even this basic level of clean water totheir citizens.
Based on the analysis here, I recommend that inter-national organizations, national and local governments,and water providers adopt a basic water requirementstandard for human needs of 50 liters per person per day(I/p/d) and guarantee access to it independently of anindividual's economic, social, or political status. Unlessthis basic need is met, large-scale human misery andsuffering will continue and grow in the future, contributingto the risk of social and military conflict. Ultimately,decisions about defining and applying a basic water re-quirement will depend on political and institutional fac-
. tors, but the concept may prove useful in meeting basicwater needs for the next century.
DEFINING BASIC WATERREQUIREMENTS
Different sectors of society use water for different pur-poses: drinking, removing, or diluting wastes, producingmanufactured goods, growing food, producing and usingenergy, and so on. The water required for each of theseactivities varies with climatic conditions, lifestyle, culture,tradition, diet, technology, and wealth, as shown over 20years ago in the groundbreaking work of White, Bradley,and White [4]. The type of access to water alone is animportant determinant in total water use. Tables 1 and2 show that the level of domestic water use varies withdistance from the water source and with the climate.
The term "water use" encompasses many different ideas
:25O-S060/96/S3J0 Water International 21 (1996) 8J-92 rWRA/Priated in the U.S.A.
LIBRARY IRCPO Box 93190, 2509 AD THE HAGUE
Tel.: +31 70 30 689 80Fax: +31 70 35 899 64
BARCODE: / < / / ? * }L O :
c
c
1. Domestic water us* by distance to vtartt
Water Use( t n n per
f water person per day)
Taolc 2. KuraJ 3ous«Qoid »titr as* ay cusuie ana wu/ctr
laadptpe,r chan I kilometertandpipe,
kilometer
ate phunbuc, pout Bush toiletCoimecnon.
g u t l e s s — , - • •
leatbu 10
20
60 to 100
150 to 400..
and is often and confusing. Among otherthings it has been used to mean the withdrawal (intake)of warn; gross water use (intake plus recirculaoon plusreuse), and the consumptive use of water. In this article,I use the term "withdrawal" to refer to the act of takingwater from a source to convey it elsewhere for storage oruse. Not all water withdrawn is necessarily consumed,however Indeed, for many processes, water is often with-drawn and then returned directly to the original sourceafter use, as in water used for cooling thermoelectricpower plants. Gross water use is distinguished from waterwithdrawal by the inclusion of redrculated water. Thusfor many industrial processes, far more water is requiredthan is actually withdrawn for use. Water "consumption"or "consumptive use" is taken here to mean the use ofwater in a manner that prevents its reuse, such as throughevaporation, plant transpiration, contamination, or in-corporation into a finished product. When the term water"use" is given, it refers to the amount of water requiredto meet a specific need or to accomplish a particular task.
Minimum Drinking Water Requirement
An absolute "minimum water requirement" for humans,independent of lifestyle and culture, can be denned onlyfor maintaining human survival. To maintain jjjg waterbalance in a living human, the amount of water lostthrough normal activities must be regularly restored.While ;he amount of water required to maintain survivaldepends on surrounding environmental conditions andpersonal physiological characteristics, the overall vari-ability of needs is quite small. Routes for water lossinclude evaporation from the skin, excretion losses, andinsensible loss from the respiratory tract. Humans mayfeel thirst after a fluid loss of only 1 per cent of bodilyfluid and be in danger of death when fluid loss nears 10per ctat f7].
Prior physiological studies have generated "referencevalues" for a daily human water requirement. Table 3summarizes several estimates of total daily water require-ments for a "reference" human. Minimum water require-ments for Quid replacement have been estimated at aboutthree liters per day under average temperate climateconditions. When diinate and levels of activity are changed,these daily minimum water requirements can increase.In a hot climate, a 70-kilogram human will sweat between
Climatic ZonePublic Stand-
pottliten/capita/day
House Connec-tion*
li ten/capita/day
HumidAverageDry
10 to 2020 to 3030 to 40
20 to 4040 to 6060 to 80
* Data Bom rural developing countries.• Without flush toilets or gardens.Source: Reference 3.
four and six liters per day without a comparable changein food intake or activity [7].
The National Research Council of the National Acad-emy of Sciences in the U.S.A. separately estimated min-imum human water requirements by correlating themwith energy intake in food. They recommend a minimumwater intake of between one and one-and-a-half millilitersof water per calorie of food (1 - 1.5 ml/kcal). Note thata food calorie is equivalent to a kcal of energy. In thisarticle, the energy content of food will be represented bykcals. This does not include the water required to growthe food consumed, which is discussed later. With rec-ommended daily diets ranging from 2,000 to 3,000 kcals,minimum water requirements are between .2,000 andN
4,500 milliliters, or 2 to 4.5 liters per day — comparatwith the data presented in Table 3 [14].
Using these data, a minimum water requirement forhuman survival under typical temperate climates withnormal activity can be set at three liters per day. Giventhat substantial populations live in tropical and subtrop-ical climates, it is necessary to increase thi< minimumslightly, to about five 1/p/d, or just under two cubic metersper person per year. A further fundamental requirementnot usually noted in the physiological literature is thatthis water should be of sufficient quality to prevent water-related diseases.
Basic Requirements for Sanitation
A "minimum" must also be defined for providingsanitation services. There is a direct link between theprovision of clean water, adequate sanitation sen ts, andimproved health. Extensive research has showc - clea'health advantages of access to adequate sanitatic ilitie.
Table 3. Arerage daily wmcer rcqoiremenci for snm>al*
Source
Average iy waterintake L: J O T per
capita per day
Vmograd [3]; Roth [9] 2.J»World Health Organization [10] 2.5White et aL [4] 1.3 to 3.0US. Environmental Protection Agency [11] 2.0National Academy of Sciences [12] 2.0Sauaden and Warford [13] 5
' During normal activity and temperate climate.•This value represents the actual fluid requirements measured forearly space flights. The recommended intake minimum for Apolloastronauts under routine conditions in 'Jie command module was 2.9liters per day
Water International
i z z protecang dnnking water rrom pathogenic b a a e n avk a n d viral and protozoa! agents o f disease. Effective disposal
• >f> o f h u m a n wastes controls the spread o f infectious agentsa n d interrupts the transmission o f water-related diseases.
ivy Unfortunately, much o f the world's population, partic-ular ly in developing countries, remains without access toc l ean drinking water or adequate methods to dispose o fh u m a n wastes. According to recent estimates, more than1.7 bi l l ion people lacked access to adequate sanitationservices in 1990, while over \2 billion people lackedadequate dean dnnking water [15]. During the decadebe ween 1990 and the year 2000, nearly 900 minion morepeople win be born in these regions [16,17]. It has beenestimated that lack of clean drinking water flnf* sanitationservices leads to many hundreds of millions of cases ofwater-related diseases and between five and ten milliondeaths annually, primarily of small children [18-21].
For the most pan, the world health community knowshow to prevent these diseases, but lacks the financial andinscrutional capability needed to take definitive and ef-fective action. While media attention to these problemsincreases when particularly acute regional crises occur,such as the recent disastrous outbreak of cholera in LatinA / ^ '.ca or among Rwandan refugees in Zaire, the morew. spread chronic problems still beg for attention fromthe world community.
In recent reviews of epidemiological studies related towater and sanitation, the provision of adequate sanitationservices was the most direct determinant of child healthaner also providing a minimum amount of water formetabolic activity and handwashing [19^20^2-24].
There are many technologies for improving access toadequate sanitation services, with widely varying water-equirements. In regions where absolute water quantity:s a major problem, alternatives that require no water areavailable. Table 4 lists those technologies that require novater except for minimal washing. Where historical cir-ruostances led to the use of wasteful, high-volume flushoilets, as much as 75 liters per capita per day, or more,iave been used. Table 5 lists the wide range of sanitationectmologies that require water. The choice of sanitationichnology will ultimately depend on the developmental;c if a country or region, the water available, the•cimomic choice of the alternatives, and powerful regu-atory, cultural, and social factors [4,25].
Given these variables, can a recommended basic water* ?quirement for sanitation be identified? Because alter-
atives are available that require no water, it is technicallyeasfole to set a minimum at zero. Two factors arguegainst doing this additional health benefits are identin-
ablt 4. Sanitation ncsnolofics that require no water
able when up to 20 liters per capita per day o f cleanwater are provided [ 2 3 ] ; and where economic factors arenot a constraint, cultural and social preferences stronglylean, toward water-based systems. Access to some waterfor sanitation, together with concurrent education aboutwater use, decreases the incidence o f diseases, increasesthe frequency o f hygienic food preparation and washing,and reduces the consumpt ion o f contaminated food prod-ucts. Accordingly, whi le effective disposal o f human wastescan be accomplished with little or no water when nec-essary, a min imum o f 2 0 liters per person per day isrecommended here to account for the maximum benefitso f combining waste disposal and related hygiene, and topermit for cultural and societal preferences. This levelcan be met with a wide range o f technological choices.
Basic Water Requirement for Bathing
O n top of these direct sanitation requirements, addi-tional domestic water is used for showering or bathing.A review o f a range o f studies in North America a n dEurope (Table 6) suggests average (not min imum) wateruse in industrialized nations for bathing to be about 7 0liters per person per day, with a range from 4 5 to 1001/p/d. Data o n water used for bathing in developingcountries or in regions with n o piped water are not widelyavailable. S o m e studies suggest that min imum waterneeded for adequate bathing is on the order o f 5 to 15 1/p / d and that required for showering is 15 to 25 1/p/day[25] . A basic level o f service o f 15 1/p/d for bathing isrecommended here.
Basic Requirement for Food Preparation
T h e final component o f a domest ic basic water require-ment is the water required for the preparation o f food.Whi le most detailed surveys o f residential water use inindustrialized countries d o not provide separate estimateso f water used for cooking, Brooks and ftters [29] estimatethat water use for food preparation in wealthy regionsranges from 10 to 50 liters per person per day, with am e a n of 30 liters per person per day. In a study done o fthe water provided for \ 2 mil l ion people in northernCalifornia, an average o f 11.5 liters per person per daywas used for cooking, with a n additional 15 liters usedfor dishwashing [31] . Other studies in both developedand developing countries [4 ,14,32,33] suggest that anaverage o f 10 to 20 liters per person per day appears tosatisfy most regional standards and that 10 1/p/d willm ee t basic needs.
The Special Case of Food
The four domestic uses described above do not includewater required to grow the food necessary for humansurvival. Minimum caloric requirements, cultural pref-erences for different kinds o f food, regional climaticcondit ions, irrigation a n d food processing technologies.
bL 21 , N o . 2 (1996) 85
jutiaon teciuiologies that require water
Technology Water Requirement Minimum Water
a (PF) toiletstsandcanafeF toilets/septic tanks: sewerage. conventional sewenje
Water near toiletWater scar toiletWater near toiletWater piped to toiletWater piped to toiletWater piped to toilet
1 to 2 liters/flush6 to 10 liiers/penoa/day3 to 6 Iiters/person/day7.5 Bters/person/day>50 liten/penon/day>7S liters/person/day
Reference! 25 and 26.
a wide range otlotizl factors afl affect total' wateri«;jirements for producing food. At present, no satisfac-tory analysis of these factors has been done. Roughcalculations, however, offer some insight into how variablethese factors can be.
Typical regional diets, compiled from the UN roodand Agriculture Organization [34], are shown in Table 7.Using average evapotranspiration requirements on a re-gional basis, estimates of rainfed and irrigated acreage,and assumptions about the efficiency of irrigation canjive a nrst-order estimate of the water requirements toproduce these regional diets. In fact, however, calculatingactual water requirements to grow food is even morecomplicated. Among the other factors that must be con-sidered are specific regional crop yield information, soflconditions, more precise rfimarir variations and effects,food processing and waste factors, and so on.
No comprehensive estimates have yet been made, thoughthere have recently been efforts to make some regionalestimates. Table 8 shows the estimated water requirementsthat would be necessary to grow the food needed to meetdietary demands in three arid regions: California, Egypt,and Tunisia [35]. California is a region with heavy meatconsumption and heavy irrigation water needs. Tunisiaand Egypt have much lower meat consumption, andTunisia provides a comparatively lower fraction of agri-cultural water with irrigation. As this table shows, thewater required to grow food is far above — by as muchas two orders of magnitude — the basic water require-ments for domestic human needs. Far more work isrequired, howevec to actually determine "minimum"*agricultural water needs to meet specific diets, as opposed:o the average values provided in Table 8.
The water required to grow food must be considered aspecial case for several other reasons. Unlike the BWRfor human survival and domestic use described in the
previous section, food can be produced in water-richregions and transported to water-poor regions. In fact,this occurs today on a vast scale and is only constrainedby internal political policies that push for domestic foodsecurity, by economic problems related o import/exporttrade balance, and by transportation Jfficulties. As aresult, providing a BWR for food pro ction, howeverdenned and quantified, should be co: -ered indepen-dently from the responsibility of goverr. ats for provid-ing the BWR for maintaining human $t al and h rsith.
Bosk Water Requirements for Natural. ryster-..
No attempt is made in this paper to d;precise BWRs to protect natural ecosyrprinciple that some water be guarantyecosystem health has also been put fctraditional water planning and manageneeds of the natural environment are -or guaranteed. In the United States ar
flow requirements have been
and
qsome minimum quality or temperatunbeen promulgated to protect environme:United States, legislation has protected rpristine rivers from development, andbeen reallocated from major water projthe environment In California, for ex:nation of federal and state laws has set asmillion cubic meters (mem) of annualronmental purposes, including the protecscenic rivers, the Sacramento-San Joacinstream and wetlands flow protectionsterfowl [30,36]. This represents nearly 21annual average runoff from the state. Sirare under way internationally. In 1994, :International Law Commission (H.Q pr
Table 6. Average residential end-osc of «*ttr is developed cowries (liters ptx person per day)
. .^n themaintai"
thecor
it of totalal efforts
Sad Vie
ToiletsBath/ShowerLaunUrvKitchenYarf/Other
Total Use (1/p/d)
86
i
UnitedStates[2T]
7060454575
295
UnitedSatesP8]9575501511
246
SwedesP7]
4070305025
215
TheNether-
lands
39J717174
104
SeveralNorthAmes:Cities[29]
906633315
225
Massa-chusetts
{291
347329224
212
ArjrCaii
Corn.:I3c;127997156
178
531
N:
;
17!
171
Water International
Taoi< ' . A'ermije Ke^iooaj Uieis, i»oy ?<r person per aaj)
Main.
PM_t K m -Ma A o n Oik Fm 9 - * __T * tatty E_i *_* FI_ »« « •*
*ftia.5aaa of Satan J5I11114}
)
r«M420n
3 741ai*
i )
a12419:
IMno
lOtS1041«H
110)«nJIJ•47
- U 7
31114}
U
n2Man} i i
107}4}
112
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JIaa
532144
too110124u
S i«2
151II
:i4}74M»704t»
101
40407454
IM137M757
123I4t
IM5*
2 »241220W20fIfOJOM4
2J»
2742I»U47M»
241129
14
a20I ]II457}
»21 .
M4}Tf
anm41»9
l i t2B
10*202•1»2
«<l
307202
I)1047
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47M
2 »:4415*12)l ittt
J «2»7
2)2>15TJ»157t515441
SI52
1(51)1112104J
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anides setting forth principles to guide the behavior ofstates. Article 20 explicitly requires "watercourse States"to "protect and preserve the ecosystems of internationalwatercourses" [48].
Despite these efforts, aquatic ecosystems throughoutthe world are under severe stress and threat of destruction.Globally more than 700 species of fish alone are consid-ered threatened with extinction [37]. In the last coupleof years, several have been added to the list, includingmajor anadromous fish species. Basic water requirements
f orotect these species and, more broadly whole ecosys-os, must be identified and provided.Ultimately, society win have to make decisions about
which ecosystems should be maintained or restored andthe indicators by which to measure their health. Then,minimum allocations of environmental water will haveto be made on a flexible basis, accounting for climaticvariability, seasonal fluctuations, and other factors. Eco-system management will have to be flexible, with decisionsreviewed frequently based on the latest information. Par-ticular care must be taken when human actions mightlead to irreversible effects.
Other Water Requirements
There are many other human uses of water, includingwater for industrial and commercial use, and for powerplant cooling and electrical generation. Water require-ments to meet these demands depend on what preciselyf ring produced, on the technology used, and on a host
other characteristics. Detailed analyses are needed toevaluate these demands, but a wide range of requirementsis described in Gleick [15]. Because water demands as-Table 8. Wttir nqalremcncs for growing food, in liters ptr person per
California Egypt Tunisia
Total daily water input (t/p/d) 5.9OS 3.242 i 9 6 4
ftrcentage of water needed to 64.0 21.4 26.9produce meat in diet (%)
Pacestage of total daily water input 71.4 69.0 57 Jmet by irrigation (%)
i These data are the water requirements needed to grow the foodconsumed within a region. Of course, many region*, including these,import and export food, and hence, water embodied in that food.Source Ren-ace 35.
sociated with these other sectors reflect human "wants"and not "basic needs," these f\fmanti<t should be providedonly after basic human needs are met.
MEETING BASIC NEEDS: ARECOMiMEiNDATION FOR AGUARANTEED BASIC WATERREQUIREMENT
Table 9 VITV™*"7** the water requirements for drinkingwater, hygiene, sanitation services, and food preparation.Recommended levels are based on fundamental healthconsiderations and on assumptions about technologicalchoices usually made at modest levels of economic de-velopment. Considering drinking water and sanitationneeds only suggests that the amount of clean waterrequired to maintain adequate human health is betweentwo and 80 liters per person per day, or up to about 30cubic meters per person per year. The low end of thisrange is an absolute minirn.iim and reflects survival only.The upper end reflects a more complete satisfaction ofbasic needs using water piped directly to the house andtoilet. This article recommends that a BWR of 25 litersper person per day of dean water for drinking andsanitation be provided by water agencies or governments.
This amount is just above the lower end of the 20 to40 liters per person per day target set by the U.S. Agencyfor International Development, the World Bank, and theWorld Health Organization, each of which also excludewater for cooking and cleaning. It is also in line with therecommended standards of the United Nations Interna-tional Drinking Vfeter Supply and Sanitation Decade andAgenda 21 of the Earth Summit
Adding water for bathing and cooking raises the totalrange to between 27 and 200 liters per capita per day,bracketing the level of 100 liters per capita per dayidentified by FaQcenmark and others [38.39] as typicalhousehold demand in water-scarce regions. Falkenmarkconsiders 100 1/p/d to be necessary to provide for someminimum acceptable quality of life [Falkenmark, personalcommunication, 1996]. The upper end of the range isequal to an annual need of about 73 cubic meters perperson (m'/p/yr). During recent severe drought in Cali-fornia, domestic water use in some of the wealthiest (but
VoL 21. No. 2 (1996) 87
7*si« 9. Recommended basic water requirements (or human ae«dr*
Recommended
(liters perpenon per
Purpose
Range(liten perpenon per
<lay)
Dnnking Water*Sanitation Services*
Coolant and Kitchen
200 to over 751510 :
5 to 70*10 to 50*
'Total Recommended Bute,Water Requirement 50
' deluding water required to grow mod (see xxtx* Tail is a true »yi"imiim to sustain life m moderate climatic conditionsand with average activity levels,- An avenge (not i"'*"'*""™) of 40 l/p/d is considered adequate forautct sanitation hookups in industrialized countries. The upper endof toe range represents extremely inefficient toilets. In water-snortregions, sanitation systems chat use no water are available, but rarelyeiaoraccri socially.4 The upper values here represent societal preferences for moderatelyindustrialized countries. Use in some water-rich regions may exceed•Jaeie amounts. The lowest values retort minimum uses in developingcountries.
water-short) regions was rationed to the equivalent ofabout 70 mJ/p/yr These levels were achieved without anysevere hardships, even in communities accustomed to farhigher levels of household water use [40].
Using minimum levels of 15 l/p/d for bathing and 10l/p/d for cooking, I recommend here that internationalorganizations and water providers adopt an overall basicwaier requirement (BWR) of 50 liters per person per dayas a new standard for meeting these four domestic basicneeds, independent of climate, technology, and culture.While billions of people lack this standard today, it is adesirable goal from both a health perspective and from abroader goal of meeting a mmimnm quality of life.
To what extent does a state have an obligation toprovide its citizens with a basic water requirement? Shouldthe international legal community consider the right to acertain level of fresh water to be a basic human right?McCaffrey [41 ] has extensively explored international legalframeworks and law and concludes that there are obstaclesto the establishment in international law of the humanright to water as a binding obligation on states. He goeson to say, however, "it is dear that, at least in some form,the right may be inferred under the basic instruments ofinternational human rights law." He further argues that:he devastating consequences of being denied such watershould require that relevant provisions of existing humanrights instruments "ought to be interpreted broadly, so asto faciitate the implementation of the right to water asquickly and comprehensively as possible.** The two in-ternational declarations quoted at the beginning of thisarticle also suggest that states have the obligation todevelop in such a way as to ensure that their use of freshwater is sustainable and adequate to meet the basic needsof its people. These declarations provide additional sup-port for the conclusion that there is both a basic right towater.
I argue here that the right to water sufficient to meet
basic needs should be an obligation of governments, wait:management institutions, or local communities. While issome regions, governmental intervention may be neces-sary to provide for basic water needs, many areas will beable to use traditional water providers, municipal systems,or private purveyors within the context of market ap-proaches. Unfortunately, there are many reasons whygovernments or water providers may be unable to providethis amount of water, including rapid population growthor migration, the economic cost of water-supply infras-tructure in regions where capital is scarce, inadequatehuman resources and training, and even simple politicalincompetence. Nevertheless, failure to provide this basicneed is a major human tragedy. Preventing that tragedyshould be a major priority for local national, and inter-national groups.
How would a proposal for providing a BWR be im-plemented? Denning and applying this principle mightrequire that the BWR be made available to all inhabitantsof a hydrologic region (such as a watershed or the areaoverlying a groundwater aquifer) prior to resolution ofhow to distribute remaining water resources. In areasserved by municipal systems, subsistence water charges —lifeline rates — for basic levels would ensure provision o 'a minimum level of service to all users. Such rates havebeen used for many years by energy utilities and are nowbeginning to appear in water utility rate design. In regionallong-term water planning, providing a BWR to all inhab-itants should be set as the highest priority — togetherwith identifying and providing a BWR for the naturalenvironment — before allocations are made for otheruses. In international river basins, such allocations willalmost certainly require joint basin committees empow-ered to make binding management decisions for the region[42].
PROGRESS TOWARD MEETING BASICHUMAN WATER NEEDS
'Vast regions of the world and hundreds of millions ofpeople lack the water required to meet the basic humanneeds proposed above. While the traditional measure ofwater scarcity has been per-capita water availability [49],it is now possible to begin to use data on actual wateruse — a measure more representative of actual humanwell-being. Using the BWR as a benchmark. Table 10lists those countries whose reported domestic per-capitawater withdrawals fail to provide 50 liters per capita perday. According to these data, in 1990 fifty-five countrieswith a population of nearly a billion people fell belowthe level recommended in this article. There are actuallyeight countries whose total reported water use in oilsectors falls below the recommended BWR for just basichuman needs.
In fact, there are strong reasons to believe that theactual number of people failing to receive the recom-mended BWR is far above the numbers reported here.
88 Water International
: J C data-in Table 10 are country averages, and severallarge countries, such as India and China, report that theiraverage domestic water use slightly exceeds 50 liters perperson per day. We know, however, that average nationalwater-use data hide qgnifir*nr regional variations, withlarge segments of populations usually falling below theaverage, while wealthier portions of the population tend
Takto 10. Comics with total domestic m r a t btlow SO 1/p/a
Country
Gambia.ViaJeSomalia\C2zvnbiqu6L'ssadsCxnibodiaTi H r m i lCentral .Africa RepublicEsiopiaRwanda
to use far more per capita. In addition, the national wateruse data used in Table 10. while the best available, areknown to be inadequate. Far example, there are severalcountries on this list that are relatively water-rich, sug-gesting the possibility that official data on water with-drawals may mi« substantial domestic water use rhar isself-supplied. Improving the scope, quality, and extent ofwater use data is vitally important.
An additional problem is that there are few data toindicate the typical quality of the water received. Poorquality of domestic water is a seven and widespreadproblem, and it is likely that many people who mayreceive more than the recommended quantity are gettingcontaminated and unhealthy water. Furthermore, popu-lation growth is increasing in most of these regions fasterthan improvements to water availability.
In contrast to these figures, domestic water use in allindustrialized countries far exceeds the BWR, though thequality of this water varies widely. In the countries ofwestern Europe, the recommended BWR is typically lessthan 25 per cent of total domestic use. In the U.S. andCanada, a BWR of 50 1/P/d is less than 10 per cent oftotal current domestic use.
What might this BWR concept imply in regions wherepolitical conflicts over water resources are prevalent, suchas the Middle East? Table 11 shows United Nationsmedium population projections for the parties of theJordan Basin [45] and the water required to provide thispopulation with a BWR. Guaranteeing the 1990 popu-lation of Israel, Jordan, and the West Bank with just abasic annual water requirement of 50 liters per personper day would require about 180 million cubic meters(mem) of water annually. By 2025, this amount wouldrise to over 400 mem. These quantities also exclude anydemands from Syria and Lebanon, portions of whosepopulation rely on water from the Jordan River basin.Estimates of the total annual renewable freshwater avail-ability for all of Israel, Jordan, and the West Bank, areunder 3,400 mem. In the Jordan River basin, a proposalto guarantee the population a basic water requirementcould mean allocating 50 1/p/d to all inhabitants of thebasin before negotiating shares of remaining water among
Table 11. Populations and basic water requirements in the JordanBasin
JordanSyriaIsndLebanonVWstBank*
Populationn m v i
1990 2025
4459 12.039I2J48 33.5054.660 7,8082.555 4.424
975 2J00
Total Water Neededto Satisfy BWR
of 50 I/p/d(for 1990 in men/yr)
78225854718
Total Water Neededto Satisnr BWR
of 50 1/p/d(for 2025 in tnan/yr)
220611U28146
2axa on domestic water use come from Reieieuces 15, 43, and 44.
' The UN does not indode separate estimates of West Banlc populationand no recent census has been conducted. Future growtn rates arehighly dependent on uncertain immigration rates. A population of 2.5million in the year 2025 was assumed here, but could be substantiallyhigher or lowerSources: Population data from Reference 55.
VbL 21. No. 2 (1996) 39
• / ,
r-inans (Syna. Lebanon. Jordan. Israel and theuans). In international basins, such a policy wouldsetting up institutional structures, such as a Joint
Basin Commission, to monitor agreements andi water. The recent peace treaty between Israel andprovides the beginnings of such a basin commis-
,. al [46,47] and Gleick [42] each raised the conceptzphmg a minimum water requirement in the contextae water disputes in the Middle East. In both ap-
iches, their -minimum" levels included considerableamounts of water required for human uses in additionto the basic needs described above.
Shuval [46] set a minimum, at 125 cubic meters perperson per year in order to satisfy domestic needs as wellas modest industrial and gardening needs. Gleick [42]proposes a lower minimum — 75 cubic meters per personper year — also including some industrial and commercialactivities. Using the higher levels proposed by Shuvalwould increase the total minimum demand in the regionto 1.200 mcm/yr in 1990 and about 2,800 mcm/yr by2025. This latter amount approaches the total for thereliable supply in the entire Jordan Basin. Satisfying this
( larger "minimum" would require taking almost all thewater now used to grow food and applying it to meetdomestic and industrial needs. This implies major restruc-turing for the region's agricultural water policy — a re-structuring that has already begun.
In California, like the Middle East, growing populationsare cocing up against natural water constraints. WhileCaiifon :a water planners and policymakers have managedto stave off these constraints in the past through massiveinfrastructure development, the era of building new largedams, reservoirs, and aqueducts is drawing to a dose.The current dilemma facing California water managersis how to meet new demands using new approaches,under traditional water projections, Califomians face ashortfall of more than two billion cubic meters per yearby 2020. more than one billion cubic meters of permanentgroundwater overdraft, declining ecosystem health, andcontinued inefficient water use in almost all sectors [30].This kind of traditional forecast, while highlighting the
( nature of current problems, no longer offers any guidanceon how to develop sustainable water policies.
A new approach presents a sustainable vision for Cal-ifornia's water resources in the year 2020 [36]. In thisanalysis, seven criteria for sustainable water use are pre-sented, including providing BWRs for maintaining humanhealth ind the health of natural ecosystems. Identifyingcesirabie end results, focusing on demand-side manay.meat, aad applying the sustainability criteria produces avision of California's water system that is far more efficientand equitable and that meets basic needs as well asproviding water for extensive agricultural production. Inthis approach, meeting BWRs first coopts only a tinytracaon of total renewable supply, but sets societal prior-lues in a more equitable way than current managementapproaches.
.-•v-90
CONCLUSIONS
Recent efforts to integrate environmental issues andconcerns with sustainable economic and social develop-ment have returned to the concept of meeting basic humanneeds first proposed nearly two decades ago. One of themost fundamental of those needs is access to clean water.This article presents the concept of a basic water require-ment (BWR) for human domestic needs and recommendsthat a BWR for drinking, basic sanitation services, humanhygiene, and food preparation be guaranteed to all hu-mans. Specifically, 50 liters per person per day of cleanwater should now be considered a fundamental humanright
Hundreds of millions of people, especially in developingcountries, currently lack access to this BWR, resulting inenormous human suffering and tragedy. Furthermore.rapid population growth and inadequate efforts to improveaccess to water ensure that this problem will grow worsebefore it grows better. This problem should be a far higherpriority for governments, water providers, and interna-tional aid organizations rhan it appears to be.
In the past, long-term planning for the managementand allocation of freshwater resources has relied upotraditional projections of human demand for water, com-pared projected demand to estimates of available supply,and developed the policies and physical infrastructurenecessary to bridge the gap between the two. Absent fromtraditional water planning has been any voice for naturalecosystems, any thought that the goals, aspirations, anddesires of future generations may not be the same as thoseof the present generation, and any explicit representationof the complex interactions between land-surface pro-cesses, atmospheric behavior, the natural biota, and so-ciety. It is time for a change. A first step toward sustainablewater use would be to guarantee all humans the waterneeded to satisfy their basic needs.
ACKNOWLEDGMENTS
Thanks are due to many people who discussed theseissues with me, including Nicki Norman. Peter Yolles,Sharad Lele, Santos Gomez, Jason Morrison, Anna Sted-ing. Bill Stewart, Penn Loh, and Pat Brenner for theircomments and thoughts. Special thanks also to GilbertWhite, Stephen McCaffrey, Sandra Postel, Malin Falken-mark. Norman Myers, Peter Rogers, and Penny Firthwho reviewed this article and offered many valuablesuggestions. Any faults or errors are my own. Fundingfor this work was provided by the Ford, Joyce Mertz-Gilmore, and Horace W. Goldsmith Foundations.
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objectives
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• to establish an international forum for planners, administrators, managers, sc.entists. engineers, educators.and others who are concerned with water resources; and
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