85:, which means that their regularization in some cases particularly affects the poor. A water audit is a key tool to assess the breakdown of NRW and to develop a program for NRW reduction. Often a distinction is made between unvalidated and validated water audits. Unvalidated water audits are desktop studies that include many estimates and their results can have an error range for real losses of ± 50% or more. Its main value is to identify where it is necessary to reduce the uncertainty of the water audit through validation. Validating water audits is a complex process that involves testing of production water meters, testing of a representative random sample of customer meters, eliminating systematic errors created through the billing process and validating the number of illegal connections through aerial mapping, field surveys or cross-references between various existing databases. In developing countries it is rare to find utilities that have undertaken validated water audits, and even in developed countries they are not systematically used. The
425:
again over the years to the same or even higher levels than before the program. Both apparent and real losses have a natural tendency to increase if nothing is done: more leakage will occur, there will be more defective meters, and information on customers and networks will become more outdated. In order to sustain NRW at low levels, investments in fixing leaks and replacing meters are insufficient in the best case and ineffective in the worst case. To achieve permanent results, management procedures related to a utility's organization, procedures and human resources have to be changed. Additionally the implementation of an
521:
production, through the avoided costs of additional supply capacity if the system is close to the limit of its capacity and demand is growing, or through the value of water sold if reduction of NRW results in additional water sales. The latter can be done by valuing water through water tariffs (financial value) or through the willingness to pay by customers (economic value). There are fewer financial incentives for a utility to reduce NRW if water production is cheap, if there is no or little metering (so that revenues thus are independent of actual consumption), or if volumetric tariffs are low.
525:
companies in the UK. The findings were reported in a major national research program in 1994. As a result of a drought in 1995/96 a number of companies initiated major leakage management programmes based on economic assessments. The situation in other parts of the world is quite different from the UK. Particularly in developing countries sectorisation is very rare and proactive leakage control limited. The benefits of pressure management are not widely appreciated and there is generally no assessment of the economic level of leakage.
109:(IWA). Nevertheless, the use of percentage figures to compare levels of NRW remains common despite its shortcomings. The International Benchmarking Network for Water and Sanitation recommends to use different indicators (percentage, losses per connection or losses per km of network) together. Losses per kilometer of network are more appropriate to benchmark real losses, while losses per connection are more appropriate to benchmark apparent losses.
544:'s (AWWA) Water Loss Control Committee recommended in 2009 that water utilities conduct annual water audits as a standard business practice. AWWA recommends that water utilities should track volumes of apparent and real losses and the annual cost impacts of these losses. Utilities should then seek to control excessive losses to levels that are economic for the water utility. In 1999 the
105:
even to monitor changes over time. When losses in terms of absolute volume are constant the percentage of NRW varies greatly with total water use, i.e. if water use increases and the volume of losses remains constant the percentage of NRW declines. This problem can be eliminated by measuring NRW not as a share, but in terms of absolute losses per connection per day, as recommended by the
1054:, August 22, 2009 by JOACHIM EZEJI, accessed on November 29, 2009. The author quotes a 2003 World Bank report saying that: "Lagos State Water Corporation holds the dubious distinction of having the highest recorded level of unaccounted-for-water in the world. Only 4 percent of its water production capacity goes towards the creation of revenue."
524:
In the United
Kingdom the assessment of economic levels of leakage has a long history. The first national study on the topic was published in 1980 setting down a methodology for the assessment of economic leakage levels. This led to the implementation of sectors (District Metered Areas) in most water
520:
of reducing NRW increases once the cheaper options have been exploited. Once the marginal cost of reducing NRW exceeds the marginal benefits or water savings, an economic optimum has been achieved. Benefits should be measured through reduced production costs if reduction of NRW results in lower water
415:
These successes were achieved by both public and private utilities, in every continent, in emerging countries as well as very poor countries, in large cities and smaller towns. All required a long-term commitment by utility management and the government – local or national – over a period of at least
80:
In most developed countries, there are no or very limited apparent losses. For developing countries the World Bank has estimated that, on average, apparent losses – in particular theft through illegal connections – account for about 40% of NRW. In some cities, apparent losses can be higher than real
104:
The most commonly used indicator to measure NRW is the percentage of NRW as a share of water produced. While this indicator is easy to understand and indeed has been widely used, it has increasingly been recognized that it is not an appropriate indicator to benchmark NRW levels between utilities or
72:
In many utilities the exact breakdown of NRW components and sub-components is simply not known, making it difficult to decide about the best course of action to reduce NRW. Metering of water use at the level of production (wells, bulk water supply), at key points in the distribution network and for
424:
Many programs to reduce NRW have failed to achieve their objectives, sometimes from the onset and sometimes only in the long run. Often they focus on real losses without sufficient attention being paid to apparent losses. If programs achieve an initial reduction in NRW levels, they often increase
116:
losses of water utilities has been criticized as flawed, particularly because real losses depend to some extent on factors largely outside the control of the utility, such as topography, age of network, length of network per connection and water use per capita. As an alternative indicator for the
276:
The World Bank has estimated the total cost of NRW to utilities worldwide at US$ 14 billion per year. Reducing by half the current levels of losses in developing countries, where relative losses are highest, could generate an estimated US$ 2.9 billion in cash and serve an additional 90 million
528:
From a public health and drinking water quality point of view it is being argued that the level of real water losses should be as low as possible, independently of economic or financial considerations, in order to minimize the risk of drinking water contamination in the distribution network.
536:
recommends that NRW should be "less than 25%", while the
Chilean water regulator SISS has determined a NRW level of 15% as optimal in its model of an efficient water company that it uses to benchmark service providers. In England and Wales NRW stands at 19% or 149 liter/property/day.
89:(AWWA) has developed Water Audit Software which allows utilities to rate the overall degree of validity of their water audit data. Guidance on loss control planning is given based upon the credibility of the data and the measure of losses displayed by the water audit.
42:, as well to the quality of water itself. NRW is typically measured as the volume of water "lost" as a share of net water produced. However, it is sometimes also expressed as the volume of water "lost" per km of water distribution network per day.
1333:
515:
There is some debate as to what is an economically optimal level of leakage or, speaking more broadly, of NRW. From a financial or economic point of view it is not appropriate to try to reduce NRW to the lowest possible level, because the
837:
Private Sector
Participation and Regulatory Reform in Urban Water Supply: The Middle East and North African Experience, Edouard Perard, OECD Experts' Meeting on Access to Drinking Water and Sanitation in Africa, Paris, December 1,
1074:
682:
545:
307:. The reduction of commercial losses, while politically and socially challenging, can also improve relations with the public, since some consumers may disgruntled to know that others are underbilled.
81:
losses. Reducing apparent losses from illegal connections is often beyond what a utility can achieve by itself, because it requires a high level of political support. Illegal connections are often in
92:
NRW is sometimes also referred to as unaccounted-for water (UFW). While the two terms are similar, they are not identical, since non-revenue water includes authorized unbilled consumption (e.g. for
117:
measurement of real losses an
Infrastructure Leakage Index (ILI) has been developed. The ILI is defined as the ratio of Current Annual Real Losses (CARL) to Unavoidable Annual Real Losses (UARL).
1349:
429:
is an efficient approach to reduce the total real losses in the long term. It is one of the most basic and lucrative forms of optimizing a system and generally provides fast investment paybacks.
426:
980:(A Draft Translation), by Achmad Lanti, Firdaus Ali, Agus Kretarto, Riant Nugroho, Andi Zulfikar as Board Members of the Jakarta Water Supply Regulatory Body Period 2005-2008, 2009, p. 128-130
848:
1246:
1377:
1162:
679:
1147:
303:
Leakage reduction may also be an opportunity to improve relations with the public and employees. A leak detection program may be highly visible, encouraging people to think about
473:
Managers: it is easier to close any revenue gap by just spending less on asset rehabilitation. (letting the system slowly deteriorate) or asking the government for more money.
1513:
Monitoring and
Managing Unaccounted for Water, Proceedings of the International Symposium on Efficient Water Use in Urban Areas - Innovative Ways of Finding Water for Cities
1313:
1182:
411:, Philippines, NRW was reduced from 1,580 million liters per day in 2008 to 650 million liters per day in 2014 in cooperation with the private utility Miya.
1089:
953:
470:
Field staff: working on detecting illegal connections or on suspending service for those who don't pay their bills is unpopular and can even be dangerous.
1027:
1346:
717:, International Water Association Conference 'Leakage Management: A Practical Approach', Lemesos, Cyprus, November 2002, accessed on November 8, 2009
359:
and other cities in
Burkina Faso, by the public utility Office National de l'Eau et de l'Assainissement (ONEA) which achieved a level of 16% in 2008;
1466:
767:
710:
973:
879:
Taqsem Khan:The performance challenges of Dhaka WASA, in Global Water
Intelligence:Focusing on performance, Global Water Summit 2011, p. 50-52.
855:
1047:
937:
USAID/Miyahuna:Lost Water and Lost
Revenue Reduction Program. Diagnosis, Planning and Implementation. Presentation, Amman, 14 February 2011
453:
Technicians and field staff: detection is done primarily at night, and pipe repairs often require working in hazardous traffic conditions.
1481:
1159:
1404:
J. Thornton, R. Sturm and G. Kunkel: Controlling Real Losses - Pressure
Management, in Water Loss Control, 2008, McGraw-Hill, p. 301-343
727:
54:(IWA) has developed a detailed methodology to assess the various components of NRW. Accordingly, NRW has the following components:
1453:
1427:
802:
The study states that its methodology allows for an accurate comparison, including water used to flush pipes and for firefighting.
284:
financial gains from increased water sales or reduced water production, including possibly the delay of costly capacity expansion;
815:, in:Water in the Arab World. Management Perspectives and Innovations, World Bank, 2009, p. 131-156, retrieved on January 6, 2011
310:
In the specific context of the United States NRW reduction can also mean reduced legal liability and reduced insurance payments.
990:
611:
1310:
1511:
Richard G. Sykes, Andrew K. Enos and Ronald L. Bianchetti, East Bay
Municipal Utility District, Oakland, California, USA:
1512:
799:
Metropolitan Consulting Group: VEWA - Vergleich europaeischer Wasser- und Abwasserpreise, p. 4 of the executive summary
464:
Politicians: unpopular decisions might have to be made (disconnection of illegal consumers or customers who don't pay).
346:, India, from an estimated 36% in 2005 to 10% in 2009 by the private utility Jamshedpur Utilities and Services Company;
1391:
Michel Vermersch and Alex Rizzo: Designing an action plan to control non-revenue water, in: Water 21, Magazine of the
636:
Paul Fanner:Driving down water loss:validating water audits for accurate NRW management, in:Water 21, Magazine of the
1496:
1025:
Yerevan Water Supply. Going Private Gradually - Armenia makes gains taking transitional route through private water
541:
86:
436:
some of the reasons why NRW levels in developing countries have not been reduced significantly are the following.
1392:
1179:
826:
Sustaining The NRW Reduction Strategy: The Manila Water Company Territory Management Concept and Monitoring Tools
812:
637:
585:
106:
51:
1086:
371:, Cambodia, from 72% in 1993 to 6% in 2008 by the public utility Phnom Penh Water Supply Authority (PPWSA) (see
1336:, Project Appraisal Document, Annex 1:Country and Sector Background, 30 April 2009, accessed on August 10, 2010
1297:
950:
1024:
650:
828:, Introduction, 2012, retrieved from the website of the International Water Association on February 15, 2012
971:
The First Ten Years of Implementation of the Jakarta Water Supply 25-Year Concession Agreement (1998-2008)
771:
484:
Another source quotes the seven most frequent reasons for failure of NRW reduction programs as follows:
30:
that has been produced and is "lost" before it reaches the customer. Losses can be real losses (through
707:
680:
Non-Revenue Water at the International Benchmarking Network for Water and Sanitation Utilities (IB-NET)
372:
318:
Reducing NRW is a complex process. While some programs have been successful, there are many pitfalls.
970:
68:
Real losses (from transmission mains, storage facilities, distribution mains or service connections)
1414:
1199:
1003:
598:
206:
The following figures are expressed in cubic meters per kilometer of distribution network per day:
96:
or, in some countries, for use by religious institutions) while unaccounted-for water excludes it.
34:, sometimes also referred to as physical losses) or apparent losses (for example through theft or
1044:
1293:
1118:
450:
Engineers: it is more "fun" to design treatment plants than to fix pipes buried under the road.
391:
Cities in Senegal, from 32% in 1996 to 20% in 2006 by the private utility Senegalaise des Eaux;
1500:
1478:
1228:
1215:
663:
1534:
1189:, February 2011, Viewpoint Note No. 326, by David Earhardt, Melissa Rekas and Martina Tonizz
991:
http://pubdocs.worldbank.org/en/496071548849630510/Kosovo-Water-Security-Outlook-Report.pdf
379:
825:
326:
In the following cities high levels of non-revenue water have been substantially reduced:
8:
1247:
Public-Private Partnerships for Urban Water Utilities Experiences in Developing Countries
731:
440:
Physical loss reduction is an ongoing, meticulous activity with few supporters among the
404:
State, Malaysia, from 38% in 2004 to 29% in 2011 by the private utility Ranhill Utilities
331:
1378:
World Bank: IDA at Work:98 Percent of the Population has access to safe water in Senegal
1276:
304:
890:
1280:
800:
340:, Turkey, from more than 50% prior to 1994 to 34% in 2000 by the public utility ISKI;
1368:
Global Water Intelligence:Debtors impact Veolia Maroc's cashflow, February 2010, p.8
1268:
467:
Meter readers: fraudulent practices might generate a substantial additional income.
353:, Philippines, from 63% in 1997 to 16% in 2009 by the private utility Manila Water;
1485:
1441:
Non-Revenue Water: Financial Model for Optimal Management in Developing Countries
1440:
1353:
1317:
1186:
1166:
1093:
1051:
1031:
977:
957:
714:
686:
39:
38:
inaccuracies). High levels of NRW are detrimental to the financial viability of
1456:, Leakage 2005 - Conference Proceedings, p. 12-13, accessed on November 8, 2009
888:
479:
World Bank, The Challenge of Reducing Non-Revenue Water in Developing Countries
74:
35:
1272:
1231:, National Drinkingwater Clearinghouse at West Virginia University, 2001, p. 1
1218:, National Drinkingwater Clearinghouse at West Virginia University, 2001, p. 2
1528:
517:
130:
The following percentages indicate the share of NRW in total water produced:
916:
460:
Nor is the reduction of commercial losses very popular among the following:
557:
93:
1347:
Phnom Penh Water Supply Authority Wins Stockholm Industry Water Award 2010
456:
Managers: it needs time, constant dedication, staff, and up-front funding.
362:
562:
397:, Morocco from 41% in 2002 to 21% in 2008 by the private utility Amendis.
382:(Prolagos), Brazil, from 60% in 2000 to 36% in 2006 by a private utility;
356:
62:
1096:, p. 55, Figures were converted from a per-hour basis to a per-day basis
1077:, quoting OFWAT for figures outside Denmark, retrieved on April 16, 2012
624:
388:, Morocco, from 32% in 2002 to 19% in 2008 by the private utility REDAL;
330:
Dolphin Coast (iLembe), South Africa, 30% in 1999 to 16% in 2003 by the
1329:
1148:
Stepping Up: Improving the performance of ChinaÕs urban water utilities
533:
433:
368:
343:
280:
Benefits of NRW reduction, in particular of leakage reduction, include
1075:
DANVA:Water in figures. DANVA's Benchmarking and Water Statistics 2010
1430:, Leakage 2005 - Conference Proceedings, accessed on November 8, 2009
1298:
Every Drop Counts. Learning from good practices in eight Asian cities
1023:
Asian Development Bank, Melissa Alipalo, Anand Chiplunkar, Mai Flor:
678:
International Benchmarking Network for Water and Sanitation(IB-NET):
1119:"International comparison of water and sewerage service 2007 report"
1415:
The Challenge of Reducing Non-Revenue Water in Developing Countries
1200:
The Challenge of Reducing Non-Revenue Water in Developing Countries
664:
M36: Water Audits & Loss Control Programs manual, Third Edition
599:
The Challenge of Reducing Non-Revenue Water in Developing Countries
394:
337:
1180:
Water in Bucharest:A Utility's Efficiency Gains under a Concession
567:
497:
Failure to mobilize the necessary human and financial resources
408:
365:, Brazil, from 58% in 2000 to 38% in 2006 by a private utility;
350:
201:
813:
Accountable Water and Sanitation Governance:Japan's Experience
708:
Practical Experience in using the Infrastructure Leakage Index
268:
These levels are given per km of network, not per connection.
1467:
Water supply and sanitation in Chile#Efficiency(water losses)
491:
Diagnoses based on preconceptions rather than experimentation
401:
385:
152:
Eastern Manila, Philippines 11% (2011), down from 63% in 1997
27:
290:
increased firefighting capability due to increased pressure;
185:
Western Jakarta, Indonesia 39% (2011), down from 57% in 1998
176:
Eastern Jakarta, Indonesia 42% (2016), down from 59% in 1998
1516:
753:
82:
31:
1259:
Altinbilek, Dogan (2006). "Water Management in Istanbul".
500:
Lack of coordination between the components of the program
989:
World Bank, June 2018, Water Security Outlook for Kosovo
548:
identified a 10 percent benchmark for non-revenue water.
125:
889:
Superintendencia de Servicios Sanitarios (SISS) (2007).
1519:'s International Environmental Technology Centre (IETC)
1004:"SUWASA Nigeria: Water Sector Reforms in Bauchi State"
73:
consumers is essential to estimate levels of NRW (see
1261:
International Journal of Water Resources Development
625:
Unaccounted-for water puzzle: More than just leakage
299:
More stabilized water pressure throughout the system
1112:
1110:
1108:
1106:
1104:
1102:
447:
Politicians: there is no "ribbon cutting" involved.
1045:Regulating to revive water supply in urban Nigeria
287:increased knowledge about the distribution system;
137:Batam Island - Indonesia 15% (2019) - (ATB Batam)
1526:
1099:
627:. Florida Water Resources Journal, February 1996
1210:
1208:
697:Water 21, Journal of the IWA, April 2006, p. 30
1515:, 8 to 10 June 1999, quoted on the website of
909:
891:"Informe de gestiĂłn del sector sanitario 2006"
112:The concept of NRW as an indicator to compare
1364:
1362:
588::, August 2003, accessed on November 29, 2009
1502:Water Audits and Loss Control Programs, 2009
1387:
1385:
1205:
610:American Waterworks Association:Water Wiser:
271:
202:Expressed in cubic meters per network length
1017:
546:California Urban Water Conservation Council
1359:
1258:
1382:
1334:Burkina Faso - Urban Water Sector Project
313:
120:
1398:
1241:
1239:
1237:
1070:
1068:
1066:
1064:
1062:
1060:
674:
672:
45:
795:
793:
791:
789:
419:
1527:
1454:Calculating Economic Levels of Leakage
1428:Calculating Economic Levels of Leakage
1300:, 2010, accessed on September 26, 2010
617:
427:Intelligent Pressure management system
321:
126:Expressed as a share of produced water
1471:
1234:
1229:Leak Detection and Water Loss Control
1216:Leak Detection and Water Loss Control
1142:
1140:
1138:
1057:
969:Jakarta Water Supply Regulatory Body:
951:EstadĂsticas del agua en MĂ©xico, 2007
949:ComisiĂłn Nacional de Agua (CONAGUA):
831:
669:
264:Bucharest 350 in 2000 and 176 in 2007
1087:, Profile of the German Water Sector
873:
824:Lanier C. Luczon and Genieson Ramos:
805:
786:
849:"Metropolitan Waterworks Authority"
728:"Singapore's National Water Agency"
503:Underestimation of the difficulties
13:
1135:
506:Underestimation of the time factor
228:California Water Service Company 6
14:
1546:
1116:
1001:
811:Mohamed Benouahi and Satoru Ueda:
662:American Water Works Association:
649:American Water Works Association:
1499:, M36 Publication, 3rd Edition,
1497:American Water Works Association
1479:Water industry facts and figures
1320:, retrieved on February 27, 2011
542:American Water Works Association
510:
87:American Water Works Association
16:Measured leakage of water supply
1505:
1490:
1459:
1446:
1433:
1420:
1407:
1393:International Water Association
1371:
1339:
1323:
1303:
1287:
1252:
1221:
1192:
1172:
1153:
1080:
1037:
995:
983:
963:
940:
931:
882:
841:
818:
760:
746:
720:
706:A.O. Lambert and R.D. McKenzie:
700:
638:International Water Association
586:International Water Association
107:International Water Association
58:Unbilled authorized consumption
52:International Water Association
691:
656:
643:
630:
614:, accessed on November 8, 2009
604:
591:
579:
296:reduced risk of contamination.
1:
612:Water Audits and Loss Control
573:
197:Lagos, Nigeria 96% (pre-2003)
99:
1249:, World Bank, 2009, p. 76-88
432:According to a study by the
219:Germany (large cities) 2.4–5
167:Dhaka, Bangladesh 29% (2010)
158:England and Wales 19% (2005)
7:
1413:World Bank, December 2006:
1198:World Bank, December 2006:
597:World Bank, December 2006:
551:
194:Yerevan, Armenia 72% (1999)
10:
1551:
666:, retrieved on May 2, 2013
653:, retrieved on May 2, 2013
373:Water supply in Phnom Penh
252:Illinois American Water 26
65:and metering inaccuracies)
1452:D. Pearson and S.W. Trow
1426:D. Pearson and S.W. Trow
1273:10.1080/07900620600709563
1150:, World Bank, 2007, p. 12
640:, December 2009, p. 53-54
540:In the United States the
272:Benefits of NRW reduction
191:Bauchi state, Nigeria 70%
1169:, WS Atkins Ireland p. 7
293:reduced property damage;
179:Amman, Jordan 34% (2010)
1443:, RTI Press, June 2010.
1345:WASH Names in the News:
1311:Operational Performance
378:Five municipalities in
216:Germany (towns) 0.7–2.4
161:MWA, Bangkok 25% (2012)
1395:, April 2008, p. 39-41
1294:Asian Development Bank
494:Partial implementation
482:
407:Western part of Metro
314:Programs to reduce NRW
240:Penn American Water 19
121:Overview of NRW levels
1227:Lahlou, Zacharia M.:
1214:Lahlou, Zacharia M.:
438:
46:Components and audits
1160:National Water Study
1043:Whichwaynigeria.net:
734:on November 29, 2016
420:Pitfalls of programs
380:Rio de Janeiro State
234:England and Wales 10
917:"Pencapaian Palyja"
754:"Adhya Tirta Batam"
334:Siza Water Company;
322:Successful programs
1484:2009-03-25 at the
1352:2011-07-18 at the
1316:2011-07-14 at the
1185:2012-03-24 at the
1165:2008-11-12 at the
1092:2014-08-03 at the
1050:2009-12-08 at the
1030:2009-11-17 at the
976:2011-07-27 at the
956:2011-09-30 at the
713:2006-09-24 at the
685:2006-10-07 at the
651:Water Loss Control
623:Johnson, Paul V.:
375:for more details);
305:water conservation
155:Tunisia 18% (2004)
134:Singapore 5% (UFW)
861:on April 16, 2014
182:Mexico 51% (2003)
164:France 26% (2005)
146:Germany 7% (2005)
61:Apparent losses (
20:Non-revenue water
1542:
1520:
1509:
1503:
1494:
1488:
1475:
1469:
1463:
1457:
1450:
1444:
1437:
1431:
1424:
1418:
1411:
1405:
1402:
1396:
1389:
1380:
1375:
1369:
1366:
1357:
1343:
1337:
1327:
1321:
1307:
1301:
1291:
1285:
1284:
1256:
1250:
1245:Philippe Marin,
1243:
1232:
1225:
1219:
1212:
1203:
1196:
1190:
1176:
1170:
1157:
1151:
1144:
1133:
1132:
1130:
1128:
1123:
1114:
1097:
1084:
1078:
1072:
1055:
1041:
1035:
1021:
1015:
1014:
1012:
1010:
999:
993:
987:
981:
967:
961:
948:
944:
938:
935:
929:
928:
926:
924:
913:
907:
905:
903:
901:
895:
886:
880:
877:
871:
870:
868:
866:
860:
854:. Archived from
853:
845:
839:
835:
829:
822:
816:
809:
803:
797:
784:
783:
781:
779:
770:. Archived from
764:
758:
757:
750:
744:
743:
741:
739:
730:. Archived from
724:
718:
704:
698:
695:
689:
676:
667:
660:
654:
647:
641:
634:
628:
621:
615:
608:
602:
595:
589:
583:
480:
261:China 52 (2006)
258:Brazil 42 (2006)
243:Russia 20 (2006)
173:Chile 34% (2006)
170:Italy 29% (2005)
1550:
1549:
1545:
1544:
1543:
1541:
1540:
1539:
1525:
1524:
1523:
1510:
1506:
1495:
1491:
1486:Wayback Machine
1476:
1472:
1464:
1460:
1451:
1447:
1439:Wyatt, Alan S.:
1438:
1434:
1425:
1421:
1412:
1408:
1403:
1399:
1390:
1383:
1376:
1372:
1367:
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1356:, June 11, 2010
1354:Wayback Machine
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554:
513:
481:
478:
422:
400:8 districts in
332:private utility
324:
316:
274:
225:Malmö, Sweden 5
210:Netherlands 1.5
204:
149:Japan 7% (2007)
128:
123:
102:
48:
40:water utilities
17:
12:
11:
5:
1548:
1538:
1537:
1522:
1521:
1504:
1489:
1470:
1458:
1445:
1432:
1419:
1406:
1397:
1381:
1370:
1358:
1338:
1322:
1302:
1286:
1267:(2): 241–253.
1251:
1233:
1220:
1204:
1191:
1171:
1152:
1134:
1098:
1079:
1056:
1036:
1016:
994:
982:
962:
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930:
908:
881:
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840:
830:
817:
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785:
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745:
719:
699:
690:
668:
655:
642:
629:
616:
603:
590:
577:
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572:
571:
570:
565:
560:
553:
550:
512:
509:
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489:
476:
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468:
465:
458:
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405:
398:
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389:
383:
376:
366:
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347:
341:
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323:
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297:
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273:
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143:Netherlands 6%
141:
138:
135:
127:
124:
122:
119:
101:
98:
75:Water metering
70:
69:
66:
59:
47:
44:
15:
9:
6:
4:
3:
2:
1547:
1536:
1533:
1532:
1530:
1518:
1514:
1508:
1501:
1498:
1493:
1487:
1483:
1480:
1477:OFWAT. 2008.
1474:
1468:
1462:
1455:
1449:
1442:
1436:
1429:
1423:
1416:
1410:
1401:
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1365:
1363:
1355:
1351:
1348:
1342:
1335:
1331:
1326:
1319:
1315:
1312:
1309:Manila Water:
1306:
1299:
1295:
1290:
1282:
1278:
1274:
1270:
1266:
1262:
1255:
1248:
1242:
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1230:
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1217:
1211:
1209:
1201:
1195:
1188:
1184:
1181:
1175:
1168:
1164:
1161:
1156:
1149:
1146:Greg Browder:
1143:
1141:
1139:
1120:
1113:
1111:
1109:
1107:
1105:
1103:
1095:
1091:
1088:
1083:
1076:
1071:
1069:
1067:
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1063:
1061:
1053:
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1040:
1034:, August 2008
1033:
1029:
1026:
1020:
1005:
998:
992:
986:
979:
975:
972:
966:
959:
955:
952:
943:
934:
918:
912:
892:
885:
876:
857:
850:
844:
834:
827:
821:
814:
808:
801:
796:
794:
792:
790:
773:
769:
763:
755:
749:
733:
729:
723:
716:
712:
709:
703:
694:
688:
684:
681:
675:
673:
665:
659:
652:
646:
639:
633:
626:
620:
613:
607:
600:
594:
587:
582:
578:
569:
566:
564:
561:
559:
556:
555:
549:
547:
543:
538:
535:
530:
526:
522:
519:
518:marginal cost
511:Optimal level
505:
502:
499:
496:
493:
490:
487:
486:
485:
472:
469:
466:
463:
462:
461:
455:
452:
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329:
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319:
311:
308:
306:
298:
295:
292:
289:
286:
283:
282:
281:
278:
269:
263:
260:
257:
254:
251:
249:Scotland 21.3
248:
245:
242:
239:
236:
233:
230:
227:
224:
222:Australia 4.4
221:
218:
215:
212:
209:
208:
207:
196:
193:
190:
187:
184:
181:
178:
175:
172:
169:
166:
163:
160:
157:
154:
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148:
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142:
139:
136:
133:
132:
131:
118:
115:
110:
108:
97:
95:
90:
88:
84:
78:
76:
67:
64:
60:
57:
56:
55:
53:
43:
41:
37:
33:
29:
25:
21:
1535:Water supply
1507:
1492:
1473:
1461:
1448:
1435:
1422:
1409:
1400:
1373:
1341:
1325:
1305:
1289:
1264:
1260:
1254:
1223:
1194:
1174:
1155:
1125:. Retrieved
1082:
1039:
1019:
1007:. Retrieved
997:
985:
965:
947:(in Spanish)
942:
933:
923:December 29,
921:. Retrieved
911:
900:February 13,
898:. Retrieved
896:(in Spanish)
884:
875:
863:. Retrieved
856:the original
843:
833:
820:
807:
776:. Retrieved
772:the original
762:
748:
738:November 29,
736:. Retrieved
732:the original
722:
702:
693:
658:
645:
632:
619:
606:
593:
581:
558:Water supply
539:
531:
527:
523:
514:
483:
459:
442:
439:
431:
423:
416:four years.
414:
325:
317:
309:
302:
279:
275:
267:
246:Stockholm 21
205:
129:
113:
111:
103:
94:firefighting
91:
79:
71:
49:
23:
19:
18:
1178:World Bank:
1127:January 10,
563:Water meter
488:Poor design
443:following:
357:Ouagadougou
237:Helsinki 18
213:Denmark 1.6
63:water theft
1330:World Bank
574:References
534:World Bank
434:World Bank
369:Phnom Penh
344:Jamshedpur
255:Ireland 29
231:Portugal 7
188:Kosovo 58%
140:Denmark 6%
100:Indicators
1281:153480716
1009:April 16,
778:April 16,
363:Paranaguá
1529:Category
1482:Archived
1417:, p. 7-8
1350:Archived
1314:Archived
1183:Archived
1163:Archived
1090:Archived
1048:Archived
1028:Archived
974:Archived
960:, p. 123
954:Archived
919:. PALYJA
711:Archived
683:Archived
552:See also
477:—
395:Tangiers
338:Istanbul
277:people.
36:metering
1117:OFWAT.
1002:USAID.
906:, p. 63
865:July 9,
768:"VEWIN"
568:Utility
1279:
1202:, p. v
601:, p. 3
409:Manila
351:Manila
1465:SISS
1277:S2CID
1122:(PDF)
894:(PDF)
859:(PDF)
852:(PDF)
402:Johor
386:Rabat
349:East
83:slums
32:leaks
28:water
26:) is
1517:UNEP
1129:2014
1011:2012
925:2017
902:2008
867:2013
838:2006
780:2012
740:2016
532:The
114:real
50:The
1269:doi
77:).
24:NRW
1531::
1384:^
1361:^
1275:.
1265:22
1263:.
1236:^
1207:^
1137:^
1101:^
1059:^
788:^
671:^
1332::
1296::
1283:.
1271::
1131:.
1013:.
927:.
904:.
869:.
782:.
756:.
742:.
22:(
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