RESTRICTED Rennrt N. PS- '.' This report is for of ficial use only by the Bank Group and specificaly authorized organizations 0: persons. 1a inay ntUL publ.u5Uh , q4UULU Vt LIor U WeLJ:UUL Bank G;oup au:o-... . *11t Bank Group does not accept responsibility for the accuracy or completeness of the report. UN- 1ERNA 7I1NAL BA[NK iO R RECO NTiRUC.iL N .A.LNTJ JJIlVELOTrIV1ERINUI iN IERNKA T IONAL DE;VELOPMEINUtJ ASSOCIATION A REVIEW OF LAND AND WATER RESOURCE DEVELOPMENT IN THE LOWER MEKONG BASIN February 28, 1972 Spec:ial Projects Department CURRENCY EQUIVALENTS This report follows the practice of the Mbkong-Committee and Secrerariat in using tne United States dollar as the nmit oI currency. WEIGHTS AND MEASURES EQJIVAIENTS The metric system is used throughout this report. One mater 3.28 feet One kilometer ('im) 0.62 Miles One hectare (ha) = 10,000 square meters 1.47 acres Cne million cubic meters (mom) 810.7 acre feet One milliard 1 ,000 mcm (,v.e vb4c -^- per I u = 31 .c.. f - e per4 sec One matric ton 1,OO0 kilograms = 2,204.6 lbs = o.984 lcng tons Cne kilovolt (kv) = 1300O volts 'ALe 1IUWSLdeWfit 1±'I) = 1 30U!J 1C1LUWaIIs~ One gigawatt hour (GMJh) 1 ,000,000 kilowatt hou.rs ABBREVIATIONS PErh,wp - ~nvit4+jv Nati.s Wemn- - o..aa4r fo,w Asia and the Par East UNDP - United Nations Development Programme AvB - Asian Develoipn-T', d canK FAO - Food and Aericulture Organization USAIM - United States Agency for International Development OFTCA - Overseas Technical Cooperation Agency (Japan) 'uSBR - United States Bureau of Reclamation A REVIEW CF LAND A1 WIATER RESOURCE DEvELOPPIEUTI r1N '1'S! LOWER IEiKNGl BASIN TABLE CF CONTENTS I. BACKGROUND A. The Mekong Committee B. The Indicative Basin Plan C. The Bankts Review of Mekong Development II. SUMMARY AND CONCLUSTONS A. Agriculture 5 B. Electric Power and Multipurpose Projects 10 C Nationnl and Rwsin ArwaGhp- 18 D. A Priority Program 20 III. THE LOWER MEKONG BASIN 22 A. Physical Characteristics 22 B, Rainfall and Hydrology 23 C. Soils and Land Use 24 D. Population 24 .IV* THE INDICATIVE BASIN PLAN 25 V. DEVELOPMENT PERSPECTIVES 29 A. Agricultural Development 29 The Present Situation 29 rL s pec .l-s fo'- Rice L-4U-.LAJ3 Prospects for Crop Diversification 32 ag~A.Lbu.ua.l J.-_ld Data ±UU Ul.Leci 34 B. Po-wer- nsvlt: ,en Vt351[L Power Demands 35 Sources of Power 37 Basic Considerations in Power Development 38 A REVIEW DOF LAND_ADID WATER RESOURCE DEVELOPMENT NTHE LWER MEKONG BASIN TABLE OF CCOTENTS (Continued) P ae Vl, NATIOAL DEVELOPMT OF LAND AND WATER RESOURCES 40 A. General Considerations 40 B. Laos hi C, Northeast Thailand 43 D. The Khrmr Renublic 45 E. The Vietnam Delta 47 VII A REVIE-W OF MIMNSTEM PROJECTS 51 A. Introduction 51 B. Poject 1EvaauatLon 52 Methodology 52 Hydro Versus Thermal Power Comparisons 53 Lrrigation and Flood Control Benefits 54 C. Pa Mong 55 D. S-tung Treng 58 E. Sambor F. Tonle Sap Barrage 62 G. General Considerations in Mainstem Development 64 Power Development 64 Irrigation 64. Flood Control 65 ±'a-vigatlon 66 Environmental Considerations 66 The Resettlement Problem 67 Project Readiness 67 VIII. A PRIORITY PROGRAM FOR BASIN DEVELOPMENT 68 Annex 1: Priority Program Annex 2: Land Area and Population Annex 3: Indicative Basin Plan Annex 4: Schematic Shoving Xain Tributary System Map 1: Indicative Basin Plan 11ap, 2: Sirmplifwedu Re'l±e Map 3: Mean Annual Rainfall Map 4: Types of Rice Cultivation in the Lowland Flood Plain of the Mekong Basin I. BACKGROUND A_ Thve W'knnvi Grn-mttee 1.01 Since the ea-ly 19Ms t-he United Na+i'.ns has suported +.'h four riparian governments in investigating the resources of the Lower Mr3erwnr 14oo-h A fo-'.w, bi o n r^ -P-- 4w.,4 ,v' t.i'+ier resource development was established in 1957 when the Cormittee for -onrnatsi~ *- Tf in4estigation-4 s Or the Lower Mekong B 4a ( Committee") was created as a result of a recommendation by the United LAULLI. Iit I Econm LL vnojrso or Asia and iAhU Far £jasI k1V.LJ% 1 C'.JL E,ach1 of trine four governments appOlnrit a ravfl'ner W.Lul' lenXp tentiary authority to serve on the Committee. According to its statute thUe untiLons ofI the Committee are to promote, coordinate, supervise and control the planning and investigation of water resources development. To these ends the Committee is authorized to: (EL) Prepare and submit to participating governments plans for carrying out coordinated research, study and investigations; (b) Make requests on behalf of the participating governments for special financial and technical assistance and receive and administer sepaalc.ely such financial and technical assistance, as may be offered under the technical assistance program for the United Nations, the specialized agencies and friendly governments; (c) Draw up and recommend to participating government criteria for the use of the water of the main river for the purpose of water resources development. 1.03 Operational assistance to the Committee is provided by an Executive Agent and a Secretariat, which are supported by the four member countries, ECAFE, and the United Nations Development Programme. On important matters the Committee is assisted by an Advisory Board of inter- national experts. 1.04 The immense water resources of the Lower Mekong Basin are as yet virtually unexploited. Only recently have the first steps been taken to conserve and regulate the runoff of the Iekong's tributaries for irrigation and hydro-electric power. However, over the past decade, the Committee has been active in sponsoring investigation and studies to measure the Basin's potential for hydropower, irrigation and flood control, in identifying projects to exploit these potentials, and in supporting the riparian governments in project preparation and implementation. The Committee's work has attracted the support, both technical and financial, of other governments and international agencies interested in promoting regional development. - 2 - B. The Indicative Basin Plan 1-.05 A notEble event in the history of Mekcng developmenm was te publication in *uly 1970, of a drafb report on an Indiactive Basin Plan, wh^sich had beZen 1repared by the Secretariat at the request ef the UomM-tt1D8. The report presrxits the first comprehensive study of the Pbkongts potential for power genera.tion, irrigation and flood control. While the report indicates the pt3ssible timing and sequence for six major projects, it does not purpOrt to :e a definitive plan. Rather it is intended as a framework for further invi3stigation and planning of the Basin's water resources. C.0 The Bank's Review of Mekonq Develrnment 1.c6 While the Indicative Basin Plan report was beine brought to completion, the Bank began its review of Basin development in response to a letter of April 1969 from the Seeretarv-Genernl of the United Nations to the President of the World Bank. U Thant's letter written in consul- tation wfith the Mekong Committee obeerved thnt r1irinnq woiflri snon be needed on major investments in Basin development, and therefore it would be in the interests of all coneerned for ' the Wn-rl i Rnnk to he mnore rI Osp1 v associated with the cooperative effort for Mekong development. 1.07 In his reply, Mr. McNamara welcomed U Thant's suggestion and said that he had discnused psihTh Bank involvement with the President of t.-. Asian Development Bank and with member countries of the World Banks and all hqd agreed that he shoild make an afirmtive response to the Secretary-General's proposal. 1.08 As foreshadowed in Mr. McNamara's reply, Mr. Mohamed Shoaib, a Vice Presidrent. rf +he B-k, was designated as the Bnk's S--i -' Representative for Mekong Affairs. Also, a division was established in the Banks Special Projecs epartment to re-vew the curr-ent status - Basin planning and development and prepare a report which would form a basis for discussionV of the Ban 's f,ut-e pEarclpation in eV1kong affairs. 1.09 E-rly in 1970, mem.bers of the -,k T r:ted the -Mekonlg Basin to become familiar with the various efforts being made toward Basin develop- ment. Tt was found that a large vol-,.e of dta cand ---prts were alr-eady available and that twio important studies -- the Mekong Secretariat's indicative Basin Plan and a feasibility report on the Pa Mong Project- would be available in draft form by mid-1970. 1.10 For assistance in assembling and evaluating data and reports, the Bank secired +he serwiHcz of S Alrtex"ander i-;bb an,d Partners of the United Kingdom.?/ Also, in view of the importance attached to the Pa Mong 1/ References to 'World Bank" or "Bank" should be understood to refer to the World Bank Group. 2/ Gibb Obtained the assistance of International Land and Agriculture, Consultants, Netherlands, for agriculture studies; the Institute of Hyrology ('UK) for nydrology studies; and Merz and McLellan (UK) for power studies. - 3 - project, the. Bank commissioned Acres International (Overseas) Ltd., Canada, to undertake an analyS 1is ^f the project's po,er benefitsa The Bank also commissioned a staff group of Resources for the Future, Inc. Of hashigt:nn, D.C to prepa e a ,port wn agnalt- A--1opmentr. .la ~At &nar earl;- stvage of rev-'lew, it$U becante ap-parent fro-m, f`i;e led observations that problems were being encountered in the implementation of "rigatiorn projects. D-scussions wit1h the Secretar-iat and the evelop- ment agencies of the riparian governments revealed that all concerned ea_lized the need for these problems to be given early attention. Thus, while the consultants proceeded with their review of major project proposals and development potentials, the Bank Review Graup focussed its attention on means for overcoming the readily observable development constrain-ts. Acordingly, the Bank cooperated with trhe Aekong Secretar-t, the UNDP, FAO and ADB in formulating a Pioneer Projects Program. The pluineer projects, wnich would be identified and prepared under the progrnam., would test, on a scale large enough to have wider applications, various techIn-iques i'or agricultural management and water control. 'With completion of the consultants' studies in December 1970, it was possible to prepare a background paper summarizing the principal findings of the Bank's review and submit this to the Committee and Secretariat in February for their review and comments. In July 1971, working papers on agriculture and on developments in the tributary basins and the mainstem formed a basis for further technical discussions with the Melong Secretariat. These and other exchanges of views with the Committee, the Secretariat and the riparian government agencies, have been taken into account in completing the Bank's review of Mekong development presented in subsequent chapters of this report. 1.13 A paper entitled "A Review of Lower Mekong Basin Development Problems and Policies", which summarizes key conclusions of the Bank's review and discusses the institutional framework for the Basin's develop-. ment and possible Bank involvement, was submitted to the Secretary-General of the United Nations on February 16, 1972 and circulated to other agencies and organizations. Parts of this summary paper form Chapter II of this report. II. SUIVlMIP AND CONCLUSIONS 2.01 The Khmer Republic, Laos, Northeast Thailand and the Vietnamese Delta, whlich together compri5se the Lower M'ekong Basin, have a corbined population of about 30 million in an area slightly larger than France.l/ SoMe 90& of 'uiis population is rural and the Basin! s economy as a whole is almost completely dependent on agriculture. Rice-growing predominates to an exceptional degree over all other activities, with ricelands accounting f'or as much as 85% of the 10 million hectares of cultivated land. Controiled irrigation and double cropping are minimal. 2.02 Population pressure is not yet severe and extension of the cultivated area has enabled the population increase to be accommodated. Although some improvements are noted for the last two or three years, rice yields have been generally stagnant at relatively low levels -- ranging from less than 1 ton of paddy per hectare in parts of Northeast Thailand and Laos to 2.5 tons of paddy per hectare in some delta provinceso Tnese yields have nevertheless permitted self-sufficiency in rice in Northeast Thailand, a substantial though dwindling surplus for export in the Khmer Republic, and a surplus in the Vietnam Delta which, with the recent improvement, is just sufficient to meet the rice deficit of other areas cf the country, Only in Iaos, and probably attributable in large measure to direct and indirect effects of prolonged hostilities, is there a rice deficit, of the order of 1i0-15% of consumption. 2.03 Prospects for the future indicate serious problems. Population growth has risen to over 23g per annum and may be approaching 3%. By contrast, currently available data indicate further availability of land suitable for rice at no more than about 20< of the existing rice area in Northeast Thailand and 10% in the Khmer Republic and Vietnamese Delta -- and such land is generally of appreciably lower quality than existing rice land. Diversification into other crops than rice is expanding and these crops constitute major exports for Northeast Thailand and the Khmer Republic. However, a major part of such diversification is taking place on upland soils which require high standards of soial and water management, to sustain present levels of production. Largely because of poor soil structure of presently uncultivated areas. the prospect for increased production using traditional techniques is quite limited. 1/ Somue relativelwy small, sparse'l- pop-ulated areas of laos and the Khmer Republic lying outside the Basin are excluded; the Chiang Rai prov4nve of ATor 4UheL M, Th-.%. IIJ1ainnd ar Ah lage vu ess pvop--' ted Central Highland provinces of Vietnam lying within the Basin are 4 .'..cl. ed 2.04 LaiLd anid water are the chief physical assets of the Basin Ceountr-ies and .he-ir JeveInrr..-nt n1.r'l v wT.ill play a mair,r role in ovemr- all economic dilvelopnent. However, resource development alone cannot be relied iupen 50 y as a mlenis for --'proI the r r ,-hjn. of the predominan",ly rural population of the Basin. Complementary efforts in ruroni devela-tro-I -q-wne%~ "I al lso be neede.d such arw farm to market roads, improvement and expansion of health services with emphnasis o th di Semj 4ati r . ofL f- -l iformatioX, d the provision of educational services which are relevant to the needs of ..-.n a g0 CU. IJes. To suppot J agr Icult. ±d. dvel L CdM.L 4o diVr the economic structure of the Basin it would also appear desirable to - it-l-dce a -11.asure of inUdast-rial Udevelopiment itL, o soruie o± tule -loJr subl= basins. Promising opportunities are agricultural processing and the establi-I -; OT-ar..fac.L.___U"I-*UIg and light industries to supply cons-wi.er goods for some of the sizeable regional markets iwithin the Basin. Apart from land and water, tde Basin nas on present knolieuge few natural resources, Forests, fisheries, and perhaps some minerals can contribute to the development of t'hie Basin. In these conditions, it is evident that for some time to come development in a meaningful sense for the great maJority of the poPpulation must be centered on improvements in agricul- tiral productivity. The Bank's review has accordingly concentrated priar_ly on the agricultural sector and related hydropower development. The following paragraphs summarize some of the key findings. A. Agriculture 2.06 Tne information available on soils leads to the conclusion, critical for development planning, that the major part of present rice lands is not, suited to other higher value crops. Exceptions occur in respect of narrow belts of alluvial soils along the banks of the river system above the delta and in some larger areas in the delta -- if wiater availability in the dry season can be improved. IMuch more limited exceptions should be found in parts of the command areas of projected irrigation schemes based on reservoir storage. 2.06 A second finding of basic importance is that, because of both low returns and high costs, the prospects for viable year-rolnnd irrigation schemes based on storage dams are poor, The low returns derive from the character of the command areas of proiected irrigation schemes, which are predominantly rice lands generally unsuited on account of soil types and poor drainage for other crops, and from the lao unit value of rice. Even an increase of four tons of paddy per hectare -- far above levels yet attained in the region -- would yield only about $200 per hectare in gross income. The incremental benefit attributable to irrigation would be significantly smaller. 2 07 Recently constructed irrigation works and feasibillty studies for new proects ln the area indica+te +thath e-rigni costs genernllv exceed the limits for viable projects based on such returns. For the two bankS of the river above the deltai ;'-rrigahle lan1d and favorable water resources generally do not coincide. Nearly 90% of the runoff of the Basin above the delta is con^entrated on the eastern side of .hp Mekong where the monsoon strikes the Annam range. Here the topography is mountain-ous areas siatable for irrigation few and the po_ uati sparse. On the west bank, rainfall is considerably lmoer and the . i.utar-:es carry ver~y littule wattr orLce th1e wet, season- en"SO Css0 adequate storage dams on these tributaries are correspondingly high and power potentia- -- and hence the costs that caL be alLocated to power - very limited, Moreover, in the larger potential irrigation areas of the west bank, the undulating nature of tne terrain and existig parcelization would necessitate substantial expenditure on levelling and consolidation. So far as the mainstem irrigation potential is concerned, two ofl the proposed multi-purpose projects would provide large volumes of storage for direct gravity irrigation. However, if the cost of such irrigation development --- excluding the cost of the storage dam -- approaches the order of $1,700 per hectare as indicated in recent studies of Pa ivbng project, the economic feasibility of these developments must be con- sidered doubtful, and until experience with ongoing irrigation projects provides more favorable benefit and cost data, it would seem prudent to place a fairly low economic value on the potential for direct irrigation from mainstem projects. 2.08 In the case of tributary projects where dams and main canals have already been constructed, the incremental costs of building field distribution systems could be justified by potential benefits. A major constraint is implementation capacity, but a phased development of perhaps 250,00 hectares over the next two or three decades can be envisaged. In selected areas the well drained alluvial soils forming the natural levees of the Mekong are suitable for diversified year-round cropping under punp irrigation. In the Vietnam Delta the extensive network of navigation and. drainage canals form a source of water which is already being exploited by low-lift pumps. The potential is good for further development of low- lift pumping, but the impact of such development on saline water intrusicn requires early attenticn. In the upper reaches of the delta the canals contain fresh water throughout the year, but in the lower delta saline water enters the canals during the dry season, The minimum dry season flow entering the delta is very large compared to likely irrigation needs, but any depletion of the flow by irrigation diversions would tend to worsen the salinity intrusion problem. Therefore, upstream storage on the mainstem to provide low-flow augmentation will become an important factor in Delta development. -7- 2.09 The lmtations on extension of the rce aea and on viable irrigation from storage dams make it the more important that attention be f cusLsJed o .n otuher ways- of i nceasing agricUluJuxc PL wVUJi.L. LU Ls also evident that both an increase in rice yields and diversification into oute cr-ops need to be considered. An increase in rice yields appears necessary to feed the growing population of the Basin, and in the case of the delta, the rest of Vietnam. in many areas of tne Basin where subsistence rice farming predominates, an improvement in rice yield's also appears as a prerequisite for diversification into higher value crops. Without greater assurance of adequate supplies of rice in poor as well as good seasons, farmers are understandabLy unwilling to venture into other types of farming. In the longer run, self-sufficiency in rice needs to be accompanied by increased diversification into other crops -- whether by dry season crops on such rice land as is suitable, by non-rice farming of upland soils or by subsidiary crops and animal husbandry on individual. farms -- if the agricultural economy of the Basin is to escape the limi- tations imposed by the low unit value of rice. 2.10 Review of existing information on the potential of the Basin for increasing rice yields and for crops other than rice indicates that a very large measure of conject-re still exists. Lack of practical experiellce even more than the insufficient soil and hydrological infor- mation makes overall assessment particularly hazardous. There are some encouraging signs. High-yielding varieties of rice appear to have had consi-derable success in some parts of the delta over the last three or four ya"rs under conditions of less strict water control than usualLy considered necessary. Where water availability has been adequate, alluvial soils in the rice areas of the delta and along the banks of the river system above the delta have grown a variety of dry season crops successfully. 2.11 The greatest uncertainty; howReverv conGerrns the large areas of upland soils above the delta. A study of land capability maps indicates that as much as 3 million hectares in Northeast Thniland mav be suitable for dry foot crops only a fraction of which is at present cultivated in any year. A similar situation prevails in the KL,m-r Repuiblic. Export crops of maize have been successfully grown for years around Korat in Northeast Thailand and in the !Chzrner Republic, but comparable soils and hydrology elsewhere, at least in Northeast Thailand, appear scarce; the same is true for areans suited f'or rubber in the KhRer RPepublic. Ln more recent years, kenaf and cassava crops have expanded to become important exports from Northeast Thailand, Thsey are nby shif " ng cul'v'at on., under which about 70% of land is fallow in any year, on the predominant nod2ol 1f' ~ Af 1 ~, ~ ~*- ~* '*~' p - In" - 1 nn** ~ W.L...U 'J.. iL.L area* iue o tit- U-W.LL.L ,_ dzoli-c soils of lo-,. -Linerent 4-t;V- r hsae. .,tht- dangers of a reduction of fertility and soil erosion as a result of over- cropping are already becorming apparent and are likely to increase under the influence of rising population pressure. - 8 - 2.12 Tn hrief; the.r are a numhbr of Pnrol7raging indications for farther diversification in areas of alluvial rice lands for dry season crons if water can hp nrovided- and for rainfed upland] soils if proper soil and water management can be introduced. To these should be added some smarll aeas of better soils such as the Bolosvens plateau a .d the Battambang area at the western end of the Great Lake in the Khmer DAA~11-,,h 7k - ..1; h h :-1- _ 4-4-4 - 1--4 h A P- -4 4- -^+t s+n"+A 'W1AA; s ~~WA.."l LL_sV%VW-,W A 1sXVsX 1G 6|s- ".V.L XLO i% v UU LV O U LCL. X tJ Vu V UAAV~- u " n HV VLvi%-6 sidered the possibilities for raising agricultural productivity apart frcm U.L4 ..i ...L*er±i conven .uau. Lsuuvag ±r-IUgation. The frst f±irlg s tLht much greatiu attention should be paid to lower cost ways of providing improved water cou.urvl. HL)UV Aov UlC delta, variations in shrle timing Of thW mOnSUOOn anl ute frequent occurrence of dry spells during the growing season present ser-ious hazards res-uting in wide variations in rice production from ye;r to year. Some modest run of the river schemes for supplying additional w-ater at the crucial early growing stage could well prove viable. Based on very limi.ted information, the area which could be so serviced is, however, likely to be quite small. More important could be expansion in use of low-lift pumps along rivers and the existing network of canals in the delta. The rate of expansion in the use of pumps in the delta indicates ccnsiderable possibil_ties and should pernit some diversification into higher value dry season crops on stretches of alluvial soils. improved drainage and better control of flood runoff can provide additional possi- bilities in some other areas. Groundwater availability does not, on existing evidence, appear encouraging, but more needs to be learnt. In the lower delta, a high priority must be rehabilitation and reconstruction of canal and other structures controlling salinity intrusion. Further possibilities appear to exist for extending this system which will allow greater use of low-lift pumps. Finally, less costly methods of delivering water from the storage dams of multipurpose projects such as Pa Nlong may prove feasible, including diversion into existing tributary river systems, to supplement water availability in dry spells of the wet season as well as in the dry season. Though not a short-term possibility, the extent of the area that could physically be serviced from such storage is so large, perhaps over 11½ million hectares in the case of Pa Mong, that such possibilities deserve careful study. 2.14 No less important, and indeed to a large extent complementary, is the invrovement of seeds. The apparent success of high-vielding varieties of rice in some parts of the delta over the last three or four years has already been referred to. No evidence was found of any careful monitoring of this experience, including levels of fertilizer and other inputs, with a view to determining the limits of more general applicability. Yet such an assessment would appear of the highest priority. It is, how- ever, not onlv in the new high-vielding varieties that a potential exists. Selection, upgrading and large-scale production of traditional varieties - 9 - to substitute for seed rice kept over from the previous crop mav well have even larger potential. The speed of adoption of high-yielding vnrietv rice in the delta - from A nepligThle Aren to over 300.000 hn in three years -- portends well for the readiness of farmers to change 2.115 A third dirction of great in,ortance to which more -atention is needed is the promotion of rainfed crops, including trial of new crops an. different; a or,nv.,,e,,CP4 n4 ~a -.-- ,-i1 -c - r-.-;1 u t; ,-. applicability for normaL farming conditions. As already noted, the pro- po-tior.L ofL Lji%s l-.ds.% _likL-'U_ IJto L7 -.L-gatedL~L Ais r' dfrFelne term diversification into higher value crops appears indispensable for a suppo_r,tin sris,n makers 4ii4- prces-w1 given the time inevitably needed to introduce new types of farming and RUp U;-DH1g .7 S'V1U6.7v ifa Uo U Jlvnsrt Ur iu LLu- aLvgU.LU1 UV Ut: U1iwU.LUUVg quickly. In this connection the use of crop rotations for proper manage- merit of upland soils deserves particular attention. 2.16 Supporting activities in such fields as transport, storage, credit and education appear vital to the success of other measures. Conditi-onis in these respects vary considerably over the Basin. uver large parts of the Basin, however, the rural transport system is inadequate to provide farmers w1ith quick and economical access either to inputs or to markets for their produce. More generally, growth in agricultural production is constrained by inadequacies in storage and processing. Shortage of people with mechanical, technical, or managerial skills, makes remedying this situation particularly difficult and points to the need for a thorough analysis of the constraints, and action in several inter- related fields. The report by Resources for the Future recommends immediate attention to providing vocational, education relevant to the experience of rural children, expansion of storage and processing facilities, and the designing of credit systems to provide short-term credit on reasonable terms to farmers for investment in fertilizer and for capital goods for farm improvement, 2.17 To sum up the prospects in the absence of greater experience of changing the predominantly traditional rice-farning patterm of agri- culture in the area is obviously difficult. However, so far as the next five years or so are concerned, it would appear that, taking account of the possibilities for a greater degree of cropping in relation to culti- vated area as population expands and existing development policies, the rice balance should be maintained. For Northeast Thailand and Laos this would imply self-sufficiency, for the Khmer Republic some margin for export once the dislocations due to hostilities are ended, and for the Vietnam Delta a sufficient transfer to other provinces to enable the countrv as a whole to maintain self-sufficienev. Some fuirther diversi- fication into other crops is foreseeable but, with the possible exception of the Vietnam Delta, not on a very significant scale - 10 - L_ I uJ D yU% WLiU. U±LLZ 1I. L .LV '~ YVW.O W 4. L ' U~L'4A~**-'.* '' problematic. There is, however, reason for optimism that income can be r[L.Lbeu forL a labg pad.->I U ofL± , JL populatlor ifJ act-.. IJJv.'A.L 4. the4 .. directions outlined above is pursued energetically on a broad front. The potential for rice is indicated by the fact that rice paddy yieIds .I Central and Northern Thailand are roughly twice those in areas of the Knmer Republic comparable in terms of soils and water regime, yields in Korea around 50% above those of comparable areas in the Vietnam Delta. While export markets for rice may be limited by the -green revolution- in previously importing countries, the domestic market should expand steadily both as a result of population growth and the potent.ial for cattle, pig and poultry raising. The rapidity of growth of secondary crops in various areas both of al.luvial and upland soils when incentives have been favorable likewise provides grounds for optimism in regard to diversification and here the prospect for export markets appears generall.y more favorable than for rice. The costs involved in developing these potentials, moreover, appear less demanding than the effort of organizati.on and administrative reform involved, Without such an effort, on the other hand, a decline in living standards for a considerable part of the Basin populat.ion may well result from the population pressure. In the longer term, the mainstem projects which the Mvekong Comnittee have under con- sideration, and to which atterntion is now turned, could provide a further impetuse But this prospect should in no way detract from the urgency of steppinig up measures for a more general improvement in agricultural product4_vity both under irrigated and rainfed conditions. B. Electric Power and Yliltirurpose Projects 2.19 A considerable nart of the activities of the Mekong Committee has been devoted to the examination of the large hydro-electric power potential of the Mekong' and its tri-htAries. The nower requirements of the Basin itself appear likely to remain small in relation to this hydro potential which coueld (PA qjnnn Mw. Major benefits -r-rPm Mek-ong power seem, therefore, likely to accrue to population outside the Basin and primarily in the main lond nern+.erq nf' Bnlgkok nnd Saigon sitim-ted at more than 600 km from the main dam sites identified. Hoiwever, in the case of Laos and the K(hmer Republic- power expmorts cold contribute directly to the Basin's development by augmenting scarce foreign exchange receipts aTnd developr.ni.et resources, while som.e part of ax.T,r power eco-nom.es achieve!d in Thailand and Vietnam would presumably redound to their Basin territories. 2.20 Of particular relevance to Basin development planning is the conclusion that + non of the mainstem proj ect woulA, on the basis of s.~~~~~~~~~~~~~ AZ _ V _ -AA VA- _C& - --^Va ^VJ N VI tJV GB .vV^z existing information, provide power at a significantly lower cost than 'U4. GI COXIMeIcI,'4V.U.L '4or- ru LLJ.. YlJAZUsO. cc"L.y ±V.- foUr1.. t.Ls cs'J partly because technological advances of the last two decades as related to neighbouring countries such as Japan have reduced thTe imporance of - 11 - moderately low cost energy among the factors relevant to the location of electricity-intensive industry, and partly due to the sparse raw material resources, Mekong power appears unlikely to prove a major determinant in the siting of industries such as bauxite refining within the Mekong Basin. The value of enclave Processing type industries not based on local materials for the economy of the Basin would, if experience elsewhere in the world is a guide, be likely to be marginal in any case. 2.21 Given that the economic advantage for powier of the mainstem projects will probably not prove large, additional considerations are likelv to blav heavilv in decisions on their building and timing. These considerations include on the one hand the extent to which national power syvtems are! irxilincp to relv on remote soures of' energy, large in relation to the total system, particularly when situated outside national territory. O^n t.he nother hanA n . ndo prtculAr- ^ +.rlv +.ance rtPoth evelment. of' the. Basin for its inhabitants, lie considerations of additional benefits which '., be 4bb-a_ed _bpps.e the m^,l -v+e rAt ' e --f soe or 2.22JkJ 7hJ tJO..LJ avi.'SA BasJ .JI P'-.'~ proposed the~rt cosrcir of4O ''manor projects in the following sequence: Sambor (1981), Nam Theun (1981), n- (-in { fQ^3N 0 S,.-_ rT^.--- - 1.t^0 D__ Tr-AS_ {ItltA7% --A T.T; -1, T, --n.-P Xd 110iu1 , , J) I'J, |JUL Ub L t;7, I I CL L LIUAJtAI l Ulii \' *1 }v IJ', C.L " I 1 I b-' , Prabarjg (1999). Excspt for Naar Theun, a project on a Mekong tributary in Laos, Withe proJeQts ar^e all on th,e al,instemU1 of the L^IIU Te-l.CL w conceived in accordance wAth the principle that powier requirements of the If-U' rc aria countries Ifo t-he peuriod 1980-200 0 wo-uld be i,t by exploiting the hycuro-electric potential of the Mekong Basin. 2.23 All of the mnainstem projects would derive their primary benefits f-rom power generation, but two of the projects -- Pa Mong and Stung Treng -- because of their large reservoirs, would have other attributes in terms of Basin development. Pa Htong would open up possibilities for irrigation in botlh Northeast Thailand and Laos and considerably reduce flooding in the upper and middle reaches of the Mekong. Stung Treng would offer possi- bilities for irrigation in the Khmer Republic and eliminate flooding of large areas in the Delta which are now subject to inundation every yearn Also the projects would substantially increase dry-season flows in the Mekong Delta. in fact, either of the projects alone would provide ary- season flows in excess of any foreseeable requirements for Delta irri- gation and salinity control. 2.24 In their review of mainstem development, the Bank and its consultants concentrated on three of the six projects -- Pa Mong, Stung Treng and Sambor. The first two obviously merit attention because they are the only projects with sufficient storage to even out the wTide seasonal variations in river flows. Also, they are not only the largest projects but also the only true multipurpose projects. Pa Mong has been studied in considerably more detail than any other project on the mainstem. Work on Stung Treng has beer, confined to mapping and geophysical investigations, and a desk study by the 1'Iekong Secretariat. Further desk studies of the - 12 - project were made by the Bank's consultants. The Sambor Project was selected for review because it has been the subject of a feasibility grade study and it was assigned priority in the Indicative Basin Plan. The Tonle Sap Barrage, which had been investigated under the auspices of the 1ibkong Committee wras also reviewed. This is a scheme for a barrage across the Tonle Sap designed to utilize the Great Lake in the Khmer Republic as a storage reservoir. 2.25 Revised and updated estimates of Pa Mong, prepared by the Bankts consultants, indicate a mid-1970 cost of US$1,133 million for the dam and high tension transmission lines for integration into the Thai power svstem. As presently planned, the project would have an installed capacity of 4-8o0 N4w and generate about 27o00n (.Wh anniiin1iv A1though the energv fro.m Pa Mong could be absorbed progressively into the Thai power system, it -wailt ar' olr'rm,nv f^r+ - re+. a an 6;f Tliilvndr t +.r1 np.nor fiemnnti in the earlv 1990's 1/ -- the earliest date when all of the Pa Mong units could be LLs+a"C eda A~.J . '.i.i..d tteefre hzas tos mnk an ,.ora. poic dec;i^n on whether it would be w illing to depend for a large percentage of its national powuer or, a single sorce located about 600 LoM asjay from the main load center of Bangkok. Since the project lies on the border between llail< UU sl Laos, pl'iOr.L U U-eeerbten the tLowyo count ies wo' Abe necessary on the legal, financial, construction and operational aspects of the ProiJectJ. 2.26 As a means of assessing the relative c"tuuio±c merit of alterna- tive modes of powi-er development end to provide a comparison between main- stem projects, the Bank;s consultants used the "equalizing discount rate (EDR). This is the discount rate which equalizes the present value of costs -- capital costs and operating costs -- of altermative power systemS developments designed to meet identical load growth. Non-power benefits of mainstem projects were considered as cost off-sets in these analyses. The EDR for Pa Mong is about 10% for power benefits alone, 9% with fuel costs for the thermal plants at 30 cents per million Btu and 10.1-v at h0 cents. If commissioned in the latter part of the eighties, permitting faster instaLlation of the paoer units, the EDR would be increased by about 1%. Average annual foreign exchange savings of the order of $70 million would also be significant. The costs of year-round gravity 1/ Forecasts of pfTer ".eeds" for pepjrlq of severnl decndes are difficulLt in any country. They are the more so when rates of growth are very highb from an sma-l base, - Timrily r1Pnrnt oAn nqqimntinns oft rates of overall economic growth and on backlogs due to hostilities; and also w.n decisinon or. the i.rioLrlt.y ofJJ` eltectiricity as agaa.inst, sV in condi-tions of strained overa1l development resources. In accepting es.t &es that ape reasonable 4 i r . that they will need to be frequently reviewed, The broad conclusions presented here may be afLeCted soireWhab as regards tiLng, but au-e u'ikel'y to be so Un other respects. - 13 - irrigation from the Pa 1Hong storage on present estimates appear too great to wa.Trrant uLnl s0f, f;~ c'nt. nttr.-hiiMon of ".et honef'i-. -in tho ovoer<11 evaluation, Flood control benefits in the delta would also be of marginal sign.ificance rbio +t~~ 44~ f~M to the _J_ao pn- 04 of the Ban Bs in.of{' occurs below Pa Hong. Some important flood control benefits would, how- e, ve r, ac-c ru ln h pe ece fte^Trr. eetm do the basis of present designs to add 0.7% to the EDR, or somewhat lower if F- v . _1 .4. J9 F.L. A . .4 lA V 2.JUW '. _U4..'.L 'J.L Uflx V.L I JsLU z.L C. a, '. C0. Mong would also, if the first major project built, contribute significantly o tk- aug.mp:bti. ox - - - sao flow -P.- 4-. delta A .d- -- eeAv s-bst-4 tially reduce salinity problems. Until more is known on the delta water A~.LLI±33U1x C±L±L dU..LUL PV1J4.WAL.L, .J.A.LU LO (1 JLL.LU", UV UIlle Ut±lI, L L U that Pa Mong - or other major projects - could provide in this regard. .A rough and possible conser-vative estiraue Lidicaues a 1 uu; u auiu±vii uo the EDR. 2.27 Although Pa I-ong project has been the subject of detailed technical studies, one major uncertainty remains; this is the resettle- ment of the reservoir population which presently numbers about 280,000 and would have grown to 450,000 by the mld-1Th801s. Lands suitable for resettling the reservoir population have not so far been located in either Laos or Tiailaande An adequate resettlement program for the popu- lation, which by the time of project completion will be several times larger than that relocated under such projects as Aswan, Kariba, Volta or Jlrgla, would be much more costly than figures used in the project cost estimates. Thus, the economic benefits of the project would also have to be weighed against the economic costs and the social and political risks of such a massive relocation and compensation program. Map studies indicate that reduction of the dam elevation by 20 m combined with modi- fications of associated structures could reduce the population affected by more than two-thirds. The Bank, therefore, recommends that serious consideration be given to an alternative project formulation with a lower reservoir level, in order to reduce the resettlement problem to more manageable proportions. Until such alternatives have been considered and an adequate resettlement program has been formulated and costed, the agricultural benefits have been studied in greater detail and information on the project's ecological impact has been assessed, an adequate evaluation of Pa 'ong project is hardly possible. 2.28 Investigations of Stung Treng are much less advanced. The proJect differs from Pa Mong in certain essential features. The main Dart of the power produced would be apportioned to Vietnam as well as Thai load centers. The reservoir. lvinq below the confluence of the Mekong and the main east bank tributaries, wrould provide major flood control for the delta as well aS aiwomont drv season flow and thus permitri. a hangee in the upper delta from floating rice to varieties of perhaps 50%0 higher vi eldP Consu1ltnts estinamPte indirect benefits from reductionr nf delta flooding of the order of $30 million annually -- against %6 million for Pa Mongn Population displaced would be less, though still of the order of 250,000 br 1985, and land appears to be more readily available for relocaion. - '14 - 2.29 Estimates based on desk studies indicate that Stung Treng would cost some 50% more than Pa Mong while energy generation would be about 30% higher. Although, therefore, the equalizing discount rate based on powqer alone can be expected to fall below that of Pa Mong - 8% to 9% on the rough estimates -- its rating on total net benefits may prove comparable. Foreign exchange savings would be somewhat higher than for Pa Mong. 2.30 Stung Treng, lying completely outside the territory of either of the main power consumers, poses in even more acute form than Pa Mong the problem of site location in relation to natianal boundaries. More- over, whereas Thailand has negligible hydropower potential to develop apart from Pbkong mainstem possibilities, Vietnam has perhaps 2,500 AS of potential, outside the Basin and on Basin tributaries, sufficiently attractive to warrant technical studies. On the other hand, Stung Treng is the only mainstem project which could provide Vietnam with a substantial measure of flood protection for the delta. It would apDear that a careful weighing of these factors by the riparian countries concerned and a deter- mninat ei-oP p^ulicy i4s required before ,rey ex+ensive anid expensive feasibility grade investigations of Stung Treng would be justified. 2.31 The Sam'oor project was studied by the Overseas Technical Coop- eration Aenc (OTCA) of Japan. Desk studies were also made by the Bankts consultants. As formulated by OTCA, Sambor is essentially a power project -- the active storage Ln the reservo-ir available for augme4tat-4r . odrf V season flow in the delta is quite small. The Bank's review has indicated. vet, a re---sion nte project's m,ode off operation. t1o i;crease actiX1re storage and to maximize the project's multipurpose benefits merits further study. Tre aJi nI such a revision would be to formulate a viable hydro- power project which would also make a significant contribution to dry- season water needs in the delta. 2.32 The Tanle Sap project in the Khmer Republic was designed primarily to augment the flood control effects of the Great Lake which acts as a huge natural reservoir for the rising ilbkong flOw duarUg the monsoon period. By erecting gates across the connecting channel, flood storage capacity could be reserved for peak flow periods and the waters released at a later period. The project cost is modest relative to Stung Treng or Pa Mong -- of the order of $140 miLlion. unfortunately, studies of the potential flood control effects have proved disappointing, Further difficulties arise from constraints on operation to reduce inter- ference with the important though declining Great Lake fish catch. An alternative design which would involve a lower structure and control onlY the outflow from the lake merits consideration. As well as augmenting the dry-seaeon flow in the delta, the project might also help to improve fish production. The former function would duplicate the major mainstem projects; but if the fish potential proves large and/or the project is comrissioned sufficiently in advance of Pa Mong or Stung Treng, the project at a lower level may prove viable. - 15 - 2,33 Long-range planning for the Mekong Delta has also received attention. Two conceptual plans have been prepared; one by Development and Resources Corporation (D&R) in cooperation with a planning group of the Vietnam Governrent, and one outlined in the Indicative Basin Plan. The two proposals have nuch in common but differ in scope and timing. 2.3L The D&R proposed a massive investment in water control works in the Vietnamese Delta over an area of 1 .6 million ha. The physical. works envisaged comnrise a svstem of levees Pxtpndinag nn both sides of the Mekong and Bassac stopping short of the Ihmer border. These levees would hp nrimnri1v fcnr flnood cnntrol eimrnm to Can Tp1n -nnr Tol1d rnntinP_e th_-P- after for the purpose of salinity control. Within the protected area exist+.ing~ can 7s TTfol ti be~ 1ld a where necess-i -r, ex+tended to tipro a complete system of irrigation and drainage channels, with a series of punmps and control structu-e to regulate the flowr of water. The estimated capital cost of the program was US$1.25 billion. The program was phased -in -Pomy stages over - period--P Of)2 y-sf-o, 1971-190(f -44ith 4l-er.- o ~ - ~MS -V a CL P J. L kA.4 /± L.'.L 4-Ua ... .JL[L 8 7 1 I - 77 .' W .. IJJ ULoAlI AiId1J '..I works substantially complete by 1986. Increased agricultural production wo '41d rC-es 1t f 4m l --rl ---'Ion __lmain J[oe 4gl --ut'1 INS. U..I.J. . " , _L4. 4. "l _JL CL L1. _C t:Yd.LD.LIJ.L1, ± L JU.d41U ±U.LUll J4LIjV.L'VtU a 1.UU.J.L,LLL c14 practices, flood control and irrigation, The major component of this .icrease, about three-quartU L, is projectved to res-ult fr'omT1 dry-seasOn irrigation 2.35 Included as one of the major projects in the Indicative Basin Plan i's a conceptula. plan referred to as Deltza Development. The m,ajor flood control a:nad irrigation works are designed to include the Delta in nnn- tmer Repubilic as well as Vietnam, Development is phased in two stages timed to coincide wJith the implementation of the two major upstream storage projects, Pa Mong and Stung lreng. rThlis stage would also include the completion of coastal embankments. The estimated expenditure during the plan period of 1980-2000 would be of tlhe order of one billion US dollars. By making allowance for the effect of upstream storage projects, t:e scope of the works would be less than the D&I?. proposals. 2,36 Further elaboration of these plans wllL require a much more detailed knowledge of delta hydrology and agronomy than presently exists. Also, irrigation on the scale proposed would only be possible following construction of the Tonle Sap project or one of the major upstream storage projects. In the formulation of long-range plans, a clearer assessment of the potential for more productive agriculture in the absence of large investments in water control appears to be required, The investigations of delta hydrology and agriculture which are currently being undertaken under the auspices of the i4ekong Committee with the help of the Netherlands Government, should, in conjunction with other recommendations made in the Bank's review, help to fill vital gaps in the information. 2.37 In summary, the Bank's reviewr concludes that the justification and timdng of mainstem project development must be vieweu in the contlexi of the increasing demand for power within the riparian countries, the feasibility of reservoir resettlement, the need for flood control in specific areas of the Basin and the advantages of improved irrigation along the river itself, However, development of an international river involves considerably more technical, legal, political and administrative problems than that of a national river. TMoreover, it requires the full commitment and the active participation of all the countries which are affected, directly or indirectly, by such development, and in some cases the chief beneficiary may not be the country in which the projects are located. 2.38 Power needs will obviously be an important determinant of the timing and sequence of mainstem developments. Although long-term pro- jections must be treated with caution, before 1990 the power demand of the riDarian countries will have probably reached a sufficient level to absorb at least one hydro-electric scheme on the scale contemplated in the mainstem projects. This demand can, of course, be met by conventiona. oil-fired or nuclear installations but in view of the lack of indigenous fuels such a mode of delrelonmenb involves a nermanent commitment by the riparian courtri. to mising energy with a high foreign exchange costo Howeverr. snmof o- n mjor hvicronoer proiects. lie outside of the countries with the largest demands. Even countries in areas with a history of poli+i_a- stabili.y ha.e shown reluctnnce to depend on plants outside of their bo.ders foa a large part of their power capacity. Thus the creation of arr egPioM^nal rll n1l forvr Hiah degree of cooneration and a mutual confidence between the countries concerned. 2.39 Irrigation demands as a determinant of mainstem development are subject .to an e-ven gre-atl -er dlegree of uncer.1.a t.LJ.VY U+h^"A Y-o. d -ds. There are three areas of the Basin in which mainstem deveiopment would pro,dAe *P^-,,, ' lagescl 4vn -- T_ +-heast Th1;iracL the area north of the Great Lake in the Khmer Republic and the IJMekong JJeltd. .U1 1i± VhUU .IJd L±1e, a f.st J-o.LJL i3 .L' rl-' to_ iv use of water stored in existing storage reservoirs; only when this has been accomplished w ll thuere be a Uasi for j-uugme-,nts on the eLonomics and timing of direct irrigation from Pa Mong. In the IKhmer Republic, the areas -which co-uld Ie co0-TUIn1deed .Irom Stung Tr-ng have yet Uo be 'u-ed in any detail. In the Vietnam Delta there is considerable scope for development of low-lift pump irrigation from existing canals. Howe-ver, irrigation diversions during the dry season would tend to worsen the salinity intrusion problem in the lower Delta. Tius, the need for a modest volume of upstream storage to increase dry-season flows in the Delta during a period of two to three months will become an important factor in mainstem development, A more detailed understanding than presently exists of the potential for agricultural development in the absence of irrigation will also be needed to assess future irrigation - 17 - needs. UtL uL±utsi o vlhe V L etnt uuma.i> Ue-L aU LjL1rU hiave ueen v~..uitua.Ly no attempts to adopt new technologies in the production of rice, the Basiln s prlncipal agricultural producto Intensive eTiorts directed to accumulating experience in the development of the water resources of the tributary basins and the delta and in promoting the development of rainfed agriculture appear, therefore, as an essential prerequisite to decisions on irrigation from mainstem projects. 2.40 Considerable emphasis has been placed to date on the need to overcome the problem of flooding. In addition to specific reaches upstream, particularly the area around Vientiane, about five million ha are subject to annual flooding in the area of the Delta and around the Great take. The pattern of agricultural cultivation has evolved around this natural phenomenon, and varieties of rice are adapted to the particular flood conditions that prevail; however, flooding does result in a depression of yields in some areas. Also, flood-dependent varieties possibly have less potential for yield increases than varieties cultivate!d under rainfed conditions. To some extent, however, the adverse effects cf floods can be circumvented by using short maturation varieties of rice in. conjunction wqith low-lift pumping which will enable a higher yielding crop to be harvested before the onset of the flood. Also, the introduction of sorghum as anl "aftor'flood;I croD in Vietnam has indicated the feasi- bility of more p:; uctive land use without large investments in flood control. Thus. -che flood problem as far as agriculture is concerned may now ass-.me a lowaer priority than it has previously been given. 2.41 In this context it is worth noting that Stung Treng is the only project canable of providing a high degree of of f d GoAnntrol in the loTer reaches of the river and in the Delta. While flood control is generally regarded as beneficial it wl result in profomnd chan.ges *n the water regime. These changes could initially be damaging if they are introduced too abruDtlv and without cnrefur advanne plann.ning_ AogreePments on the mo*e of operation of Stung Treng would be necesscary to protect the interests of Viet.nnm Anni the Xhymr Raniihci the riparns who would be affected by the project, 2.42 The Bankts reviewi has confirmed the findings of the Mekong Commi||+-ttee that 11tip -pos de.v4loprn of we . g :vr is 44c,- - cally feasible and in the long-term holds considerable promise for regional econor4-c developr.r.t Uo-e-v- before -uch plns- can 1e t:nlae ant **"~~~~~~~~~~*~~~~~~~~ ~~~~~~ V L~~~~~~~~~~~J~~~~~J6 U~~~~~~~~~~~~±U.L~~~~~~~~~~~ ~~~~~~U',4I jJJWJ.~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Ud,LI U~~~~~~~~~~~~~~~~~~~~Z ~~~~~~~L±L~~~~~~~~~~tIjt~~~~~~~~~~~U ±.LIL,U~~~P.Z ,L) Ud l U UL U i firm decisions on the timing and sequence of major investments, numerous problems attendant to the ao ssessmet of projec costss and beneits and to the Joint development of an international river will have to be resolv-ed. - 18 - C. National and Basin ADDroaches 2.43 Consideration of the development of the Mekong Basin is rendered more complex by the fact that territories of four countries are involved and that for two of them. Thailand and Vietnem. the territories within the Basin constitute only a part of their total national territorv. Even if the Basi n lan entirely within one noimtrv. problems of priority and allocation of resources, of local ine-rests, and of nolitical balance woulAd nrise. The hnstory of m.i nor, r morage schemes bears ample testimony to the difficulty of securing .n accoptable nl 1 r-tEinn orf costs. -5ih riff4emil tie na p -r+A4i*In nlyvr -tri dent wlna-m as is often the case, the costs and disturbance of construction is con- centrated upstreamw..uhere the most advantageos sites for storage nd power potential are found, while the maj&r benefits lie downstream or in ~vban centers outside the Ba;. Wjthj.p, a single coun.try, nAia+v4vtn+nt in national financial assistance can help in finding a solution0 katween t.O or more countries, the fndiA4g of a-, acce'a1;-e s. is - tably more difficult, though it is possible that international financial assistan.ce, w-here available, c play a catalyst role, It is nonetheless of even greater importance than in the case of a single country that the SArIeUIJQ as weJ.-. as 4i; ; k.._ LI.LV p.rJyvope r JeJ,cJ sh ' .d O bf.L'Ju." U ' .Ly.LJ recognized by a:'.. concerned; ul.thout such a common basis, the possi- bilities of coo -rative actiofli -ust ineviLabUly be reduced. ViUch liJghu must be shed on the problems before enlightened self-interest can play J.LL' 2.44 The beneIits O0 cooperation between the riparian countries in the development of the Hekong Basin have to date been discussed largely in terms of total estimated costs and benefits of the proposed mainstem projects in an integrated development of the river system and with reference to agreement on mainstem low-flow water use. rlhese certainly constitute a most important aspect and the desirability of regarding the river and its tributaries as a total system from the beginning can be fully endorsed. Cnly in this way can benefits be maximized in relation to costs and the international difficulties often caused in other river systems by isolated, independent action be averted. 2.45 It is not infrequently suggested, on the other hand, that because the four national territories of the Basin are so dissimilar and because priorities for their development must be determined in the context of national planning involving non-Basin territories and their problems in the case of Thailand and Vietnam, the major emphasis should be on national approaches to development of the respective Basin terri- tories. The four component territories differ substantially in physical conditions, in ethnic groups, in population density, in degree of inte- gration into commerce, in transport facilities and in education levels to mention only a few of the important considerations for policya It is indeed for this reason and because of the need for a national perspective in determining priorities, that the Bank's review stresses the desirability of considering separately the potential of each of the four component territories of the Basin. .. 19 - 2.l16 The nationaL and Basin-wide annroaches are not. however, regarded as being in antithesis but as strongly complementary. Apart from the mninstem projects, which rIi-Ar.-ty nfefpct mrep thnn nne ripnrian country, joint riparian efforts can be of great assistance to the sub- basinIs de.velopment y economizing Basin studies and expert.ise in communicating relevant experience, in preparation of agricultural projects &-d nA 4rg -ernn!iz4% -Nr in-maA-Jc"er air .d tehr.i4elasis TvoP ^-n- cr-ra+. conditions in the Basin, shortage of expertise and requirements for tra4rA4.Aga --'. 4a- la+ a- --no-tn+ as -hrt Pa of *4renance. Th 4 pioneer A L &&r C&Y.kJ MGL C&V LWLO 1.1 & JIJPW~.L VJC.L& LJ .QL'.J. WL r S W .1. L~.LAA '..A-- -S -' project program is illustrative. Fourteen pioneer project areas are being se'lected thrvu6h D-4 4he 4--4n tots,o,as ' ag rog o have wider practical application, various techniques for agricultural management aLLLU WdA'VL cL L- r .4 02 * They .e uteing ElUU I U Uw.tUiklUU so Wi9 VA experience gained will have relevance for other parts of the Basin irres- - c 0J. r- V.1. nauati.LL1. 'U0U.1dnar.A.U AD sar timWL b.LIi, a sysOtemi V.f .,lti-LJ. lateral financing and riparian involvement has been created which facili- Late ,hetA PIJV.U5.0iS I 01 n UtrI O .LVLJIa.J LI&1VLna.L andu UtcwI;al. a Ussi tanc support. 2.47 Moreover, it is only by close interaction between the national and Basin approaches, that the experience in the development of sUb- basins can contribute to the evaluation and design of the major projects. A close working relationship between the program makers at national and Basin level is, in addition, essential to widen the appreciation at national level of the benefits and limitations of the major projects proposed. 2.48 None of the mainstem projects with the possible exception of Tonle Sap, seems likely to be appropriate for completion for perhaps 15 years or more. Far from regarding this as a long period, it should be considered as uncomfortably short for the formulation of a detailed approach to the development of Mkong Basin and Mekong River. Time will also be required to gain the additional experience required for detailed project formulation and realistic assessment of agricultural benefits. Riparian agreement, detailed design, arrangements for finance and operation, and actual construction may require a dozen years or more for such major projects as Pa Mong or Stung Treng even when, as for Pa Mong, much of the data and site testing have already been accomplished to feasibility grade. Accordingly, although the need for basic decisions on the mainstem projects is not regarded as imminent -- and in any case appears impractical in present conditions -- the interaction and, where necessary, coordination of national and Basin approaches is not a matter of only fature concern. It is rather of immediate urgency. - 20 - 2.49 In the longer run, such activities could have more far-reaching effects. The economies of the four riparian countries are at present largely isolated from each other. Trade between them (excluding entrepot trade in the case of Laos) represents onl-y a few percent of their total foreign trade; their exports, almost exclusively agricultural products, are competitive. Yet in the longer term, benefits may be derived from greater integration of their relatively small domestic markets. The Mekong effort could provide a basis for greater cooperation in other fields, perhaps extending to neighbouring countries. 2.50 In this context of the complementarity of the Basin and national approaches, some brief observations on national planning appear appropriate. None of the four riparian countries have long-term perspective type plans for development. In Thailand, however, a five-year development plan for 1972-1976 is being drafted, including a five-year plan for development of Northeast Thailand. Here, at the invitation of the Thai Government, a Bank team has been able to review more closelv the nroblems of overall development, relative priorities of water resource projects and relation- shins to nation-L programs. Conditinnq in the other territories of the Basin have precluded similar studies. It is understandable that in Laos, the Khrinr RepuhbliP. nnd Uietna.vi i-mmediate prohlem- domrinate to mich ann extent as to give. lang-term pluLning relatively low priorityo While At.t.tntiyon ;q in - i a-'+. c--nc ; inimn i-n11 fnli ry in+."Ji=-Q to.e thn nriontion of broad policies towards future development, it is probably unrealistic to -ntircir,a.~t.l los attention b~~ y the four coijntries to detailed longi-term planning on a Basin-wide basis at this time except as an adjunct to prss;ng7 shote tem E,gam 2.51 There is a n evident danger these circumst nces of planning at national and Basin levels getting so out of step as to render their integratior difficult, with a res- t-ng isolation of the B. p1 It is the more important that the Basin-wide effort take into account the -nc-n r A ndr w 4-I-th - .4--4 a.a A'- d 1-lr.r.v+ affo7ts r-st tfl%t' '.,'.SA C6 .L,UUL t LA 04L . WL,.Li.a,L UlI,~ AAL .W.A - i.A~ yV JX AIIAJsh ~A.st3 £ -1- necessarily operate over the years immediately ahead. For the reasons *-ndi cA a t iv-a 44-a ,s.. not 1D.s.ble -o .del-t-ake an assessme,ntP development priorities in each of the riparian countries in relation to D. A Priority Program 2.52 The Bankts review confirms the priority of agriculture in Basin development and emphasizes the merit of regional cooperation in the development of the Basin's land and water resources. However, the review also concludes tnat most, if not all, or tne promising opportunities for land and water development in the Lower Mbkong Basin require substantial f'urther preparation before they could be considered ready for 1mplementation. - 21 - Recognizing the ureent need for project preparation, the Bank's review has identified a "Priority Program" of pre-investment studies to promote investments in the neriod immediately nhead and to lead Iogir11y into a longer term basin development program. 2.53 The program includes studies and investigations with implications for the Basin as a whole, including the preparation of a Basin--wide progrA of pioneer agricultural projects which is already funded, selected pre- invrestment studies in each of t 'An " M WL othe Basid , L.n the most urgent follow-up action in the preparation of multipurpose projects othe .-bkong lRisver. A preelirndnary esuiJ,acLte indic-at1es a firiding requir-emi,ent of US$12.0 million which might lead eventually to follow-up investments on u.eorder o Lky v 1,U`,2.,- idHon. 2.54 It is recomnmended thIa this progrm, many elerments of which ha e already been adopted by the Committee, should be contained in the work program- of the Co-mittee. - T addition to the pioneer project programrl wihich is expected to lead to roughly $50 million of projects, the prioritJy program places emphasis on investigations that could be speedily concluded and form the basis for further investment in field distribution systems for existing reservoirs in Nor-t.heast Thailand and the Khmer Republic. Investigations o2 the potential in the Khmer Republic for improving the productivity of r-ver-bank farms by crop diversification and of the Great Lake fisheries, and in Northeast Thailand of flood protection in the lower reaches of the Ham Aiui are also included, In the Vietnam Delta, emphasis is on evaluating the further poaential for low-lift pumping and expanded use of high-yielding rice varieties, on carrying forward investigations in relating to three salinity control cum irrigation projects, and on hydrologic data collection required as a basis for more comp;:ehensive planning of Delta developmento In Laos, investigations requjied for extension of the Nam Ngum project and for determining the further potential of the Nam Ngurm Valley below the dam are included along irith studies to enable finaL decisions to be taken on flood protection of the Vientiane Plain. 2e55 Investigations of Basin-wide significance include further stud-"es of Pa Mong, particularly relating to reduction in dam elevation, studies of a basic redesign for the Tonle Sap project, a consolidation of the work so far carried out on Stung Treng, further studies of the- Sambor project, and a continuation of the delta studies undertakcen bby the Netherlands team. Particular importance is attached to a Basin-wide program of research and field trials of techniques for improving agri- cultural productivity under rainfed conditions. III. THE LWR MEKONG BASIN A. Physical Characteristics 3.01 The Mekong, one of the world's great rivers and tenth largest in terms of annual flow, begins its 4L,200-kilometer journey to the sea in the mountains of Tibet. The Lower Mekong Basin begins where the river leaves China and becomes the border between Laos and Burma. It covers an area of 620,000 square kilometers, some 77% of the total drainage area of the Mekong, and includes virtually all of the land area of Laos and the Khmer Republic, the Northeastern provinces of Thailand, and the Delta provinces and part of the Central Highlands of the Republic ov Vietnam. The following brief account of the salient features of the Basin is supplemented by the maps included at the end of this report. 3.02 The Basin is bounded to the east and north by the Annamite Range, which extends from the Central Highlands of Vietnam through the entire length of Laos. The range is subject to high annual rainfall and contributes nearly 90% of the incremental discharge of the Mekong in its lower basin. Most of Laos is mountainous and forest-covered; areas of level land suitable for permanent cultivation are found along the river vallevs; the banks of the Mekong and in plateau areas such as the Bolovens Plateau and the Plain of Jars. 3.03 Except for low mountain ranges on its western and southern borders, Northeast Thailand is an undula+ing plain beiptin 1OO and 200 meters in elevation. The two largest rivers are the Nam Mun and Nam Chi; theeir combined drainage area, co.mmonly known as tUhe Mun-Chi Basin, occupies two-thirds of the land area of Northeast Thailand. The remaining or.e=-o,iA ot h rgo is, -a -ra strip ofP lar.d along +the rightk ba-|o VA" ~4 AJ~ UJLAW A Vr .LW 0I CZ VA %JCA 0 VI .LJJ %J. ~~L IL LO. A.. WA SVI - - --- -- the Mekong. The broad valley lands are primarily devoted to paddy cultivat+ion. In recen+ years +here has been a considerable increase in the use of upland areas for such crops as kenaf, maize and cassava. Some ofP +e Ilowest- ra,r 'a" areas in tedsfnaein4L; westerr. pvce of I wil JAJW U S L..J.A. A. S I .L U11 LDd%0.A1 Q%.LV ..11 ULSII WVU0 VUL LA 1J5 '. V I.L±0 ' Northeast Thailand. 3.04 There is a marked imbalance in resource endowment between the .lef uarU rlgllu buax.uws of '-he Mkri±g ±r, II its upperrae Lati±ua IarJdu Is more plentiful in Northeast Thailand but the water resource is limited, whereas duu iseau ample water but limited areas oI cultivable laiiu. 3.0v The Mekong plain, lying at an elevation of less than 100 meters encompasses most of the Khmer Republic. A notable feature is the Great Lake, a unique natural reservoir linked to the mainstem of the Mekong by the Tonle Sap. Water enters the Lake from the Mekong in the flood season, and flows from the Lake to the Mekong as the flood recedes. mTe area surrounding the Great Lake is similar in topography and climate to North- east Thailand. Numerous tributary streams of the Great Lake rise in the hills forming the northern and south-western boundaries of the Khmer Republic. The Plains surrounding the Great Lake and Tonle Sap are largely devoted to rice cultivation. Some upland areas have long-established rubber plantations. - 23 - I.- 06A The.-fl-n M ng..njl. a Si frn V^mpI C.e m n" +ak- Y0- Republic to the South China Sea, consists of the vast alluvium built up by 4he4 rror Ex.cept f-or coas+al -m-.4 4-,-.- .-.4 A a-r. t-e c, s 4u-lp soils of the Plain of Reeds the delta alluvium constitutes the most rL J. J. LILn thle Basin. EJvery year 4[rom Septem,b-er 4to) NoveUr,i,ber_, whIeII the Mekong is in spate, flood water overflows the river banks inundating large areas of 'uie deltUa lands in the uler Republic and Vietnarm. Rice cultivation practices are adapted to both the timing and depth of flooding, and about one-half of the rice grown in the Delta is fiood dependent. A prominent feature of the Vietnam Delta is the long-established network of navigation and drainage canals. B. Rainfall and Hydrology 3.07 T'he Lower Mekong Basin is situated in the center of the monsoonal region of Asia and is affected by the annual regime of monsoon winds and precipitation. Sheltered from the northeast monsoon by the Annamite mountains to the east, the Basin has a pronounced dry period from November to March. The southwest monsoon, carrying with it moist air, covers the entire lower basin giving rise to a rainy period varying from May to September in the north and west, and from May to November in the south. The highest rainfall areas are the central and southern parts of Laos and the western coas-al areas of thep Delta (2,000 - 2,400 mm). Large areas in Northeast Thaila-o and the regions surrounding the Great Lake are shieldecd by the coastal ranges and receive less rainfall, ranging between 1,000 and 1,4oo mi. The main crop-growing seasons correspond closely to the seasonal rainfall patterns. 3.08 Entering the Lower Basin above Chiang Saen in Northern Thailand the Mekong has an averaze annual flow iust under 100 billion cubic meters. By the time the river discharges into the South China Sea over 2,500 km downstream. the average nnn-ul flow has increased to nearly 500 billion cubic meters. By far the major portion of this increase in flowi comes from the Laotian left bank of the Mekonng With an average unit run-off of 1,100 mm, rising to over 2,000 mm in the case of some tributaries, the area on the 'Left hank onntrJhutqes near1y 9n0 of the increase in fle-w from less than 60% of the drainage area. In contrast, the Nam Mun, the major trihit.ry on +he right bavnk, which drains a large area of N ortheast Thailand, has a run-off of about 200 mm or only one-tenth of the run-off of the Ieft+. bank tributaries. ,R -o '9ho f-I ^T.t 4t, ho -,.-~ ..- A-4- A 1 - - ..-. .. _ .P11 . St ,._, _ W - a - S0...VS A. v Srom rii v w.1±4 vaL.L so baJ 5) the hydrograph reflects the pattern of rainfall distribution during the year. T ..L Sl starts to rise ol'o4-UW.ing, Lthe UonstD of UeL± ZUUtALiWetU monsoon in May or June and attains its maximum level in September or October. It falls quite rapidly until December anu recedes more slowly during the dry period of the year. At Kratie, in the Khmer Republic, just above the delta reaches of the river, the lowest recorded monthly mean flow is about 1,360 cubic meters per second compared with a maximum of 73,600 cubic meters per second. 3,10 BlOnw Phnem p.nn- +.he rivp-r div^des into two nrrm_s before continuing its course through the delta -- the Mekong on the east and the Bassac on the west. Further dr nstream the %Mkoncg dviAdes intO five branches before it enters the sea. Although the storage effect of the Grea-+ Tke redcespeak f'l s .tohe .Mek,I Delta, 74l.- - ^- from the six delta branches causes flooding of over 3,000 sq. km each year . tsw ,uso season,e 4gt> --es-A asth ow,te Mekong and Bassac recede, the effect of salinity intrusion is felt over lage areas ofth aw.-Dlta. C. Soils and Land Use 3.11 At present about 10 million ha of the Basin's total area of 64.5 fillion ha is cultivaTved. About 85% of tne cultivated area is used for rice. The major rice producing areas are the tributary flood plains of Northeast Thailand, areas surrounding the Great Lake, and the Mekong Delta. Most of the land suited to rice cultivation by virtue of topo- graphy and water regime is under cultivation; for the Basin as a whole the scope for lateral expansion is probably between 10 and 15%. Apart from some of the fertile alluviums in the Delta, the ricelands offer limited prospects for crops other than rice. 3.12 In the uplands the soils are generally of low inherent fertility and where they are in use it is primarily in the form of shifting culti- vation. Permanent cultivation of these soils would require more advanced. techniques of farm management and soil conservation than are followed at present. The limited areas of fertile upland soils which can support permanent cultivation are mostly already in use for crops such as rubber (Khmer Republic) and maize (Northeast Thailand). D. Population 3.13 Current statistics place the 1970 population of the Basin at 30 million, and the growth rate in the past ten years at about 3% per year. Over 90% of the Basin population is classified as rural and most of these are dependent for their livelihood on agriculture, Population of the urban centers has been growing much faster than the population generally -- from 5 to 10% annually -- reflectinz a gradual movement away from the land. Phnom Penh (500,000) and Vientiane (1050000) are the largest urban centers in the Basin, In Thailand and Vietnam the largest towns and cities lie outside the Basin. Bangkok, the capital of Thailand, has a population of over three million. Saigon, the capital of the Republic of Vietnam, has a population of more than two million. These cities as well as being the maior ports of their resnective noimtries are n1so their chief centers of commerce and industry. - 25 - IV. THE INDICATIVE BASIN PLAN 4a.01 In 1962 the Mekong Committee noted the desirability of a comprehensive water resources development plan for the Lower Mekong Basin and requested the Secretariat to prepare an Amplified Basin Plan (so called because it was intended as an amplification of a 1957 ECAFE study). To meet this requirement, it was necessary to embark on a major program of data collection and analysis; to undertake project reconnaissance and feasibility studies; and to analyze and compare numerous alternatives for water resource development. In many fields, such as economic analysis, hydrology, hydrography, mapping, geology, project reconnaissance and feasibility studies. the _ mmittpe and Secretariat received considerable assistance from cooperating countries and United Nations specialized .02 The Secretaiat worked closely withEGAFE Division nfA Water Resource Development and a draft report was completed in June 1970. This re-port w_as Meviem,ged w-i+uIn eacbh of +>en Nxa+ional Mekoneg Cr mynttee's andr waso th.e subject of a seminar in Bangkok in November 1970, attended by more than I5 Erep --resentatie 4 of - . Parian; - --- -ovrr,--ts copr+; ontis *O ~t JC V~ J V LV '4.A. A.L J. .1.L0.11 r%V U.L1111UIL~JIUO, .J.J90 .V41 , international agencies, the Secretariat, and interested foundations, unr±i ~U.LUO ZLL U other Vrg" i za s ±In Latue 170 SIe Au-vriOsory Board recommended, and the Mekong Cor=3ttee approved, changing the title to Tr 13: I'_ - : - _ _ - To - - - _- - _- L 1- - - - _- = - _- - -A :. 4--1 - - 4 -. ±iLUlcatL VU DabIl i-. .-. l liBe dralt reSioru ihas Lw Umw eentss v.sd Lak I it ±.C consideration the comments of the Advisory Board, the Mekong Committee, ancd tihe pairtiipants in the seminar; the report is to be published in early 1972. 4-03 nTe Indicative Basin Plan report outlines a development program involving a capital expenditure of more than US$8,000 million over a period of 30 years. In terms of project content, it includes a Short-Range Plan (1970-1980) and a Long-Range Plan (1980-2000); Annex 2 to this report contains tabular summaries of the tvTo plans and a map showing the location of the projects is included at the end of this report. 4.o4 The Short-Range Plan comprises a number of on-going projects and some new multipurpose and irrigation projects in the tributary basins and the Delta, with a total investment outlay of $795 million. The Long-Range Plan includes five major projects on the mainstem of the Mekong, one large hydro-electric development on a tributary, and a plan for providing a high degree of flood protection in the Delta coupled with irrigation and salinity control. Three of the mainstem projects are primarily for power (Sambor, Ban Koum, and High Luang Prabang), the other two projects (Pa Mong and Stung Treng) with their large reservoirs would provide a high degree of flow regulation, flood control and irrigation, and would also be the two largest power and energy producers. 2u 4.05 All of the major hydro-electric powerplants and the main load centers in the riparian countries, principally Bazigkok and Saigon, wouid be interconnected by high-voltage transmission lines. The Plan envisions tlhe output )of the mainstem hydro-electric plants being purchased by tne public electricity supply agencies in the riparian countries, so that rMekong power would be combined with other sources of power to meet requirements in their respective service areas. 4.06 The projected demands for power and energy for the four Basin countries, used as a basis for the Plan, are summarized below. The Plan is designed to meet virtually all of the growth in demand after 1980 by hydro-electric generation, primarily from mainstem projects. Indicative Basin Plan Power and Energy Demands 1970 1980 1990 2000 Power &Th1) 1,180 5,04o 11,800 24,000 Energy (GWh) 5,470 26,200 64,l0o 129,000 Averagre annual growJth in enerev demand (M) 17 9.2 7.3 4-07 Because of the 1 arge storage reservoirs ren uired for n+.iMiH nm development of the power potential at Pa Mong and Stung Treng, a vast potential for) irJrigation would be created. It would be possible to divert water to large areas of land in Northeast Thailand from Pa Mong, and to the nnrthern part of +he AKhm.er Repnnhlic frnonm S+ung T-erna Also, because of the change in the seasonal pattern of run-off, year-round irri gation in te Mekor.g Delta would n.o lon.ger be con.strained by lack of water, and the problem of salinity intrusion in the lower reaches would be alleeviated. In addition, the atte.nuation of Menon4 g floods by the Stung Treng reservoir would relieve annual flooding in large areas of the Delta n-d i.L1LjJ±v UtLh techA.d..l ad LU Lconor,icA fibLiL.L.L,y O.L oLi'UUoo prUoUtet.LVn dikes in the upper and middle Delta. 1408 The Plan aims to provide irrigation to about 1,450,000 ha by the year 2000. TsLis would be rmade up as follows: - 27 - Indicative Basin Plan Area Irrigated by Year 2000 (thousand ha.) Direct Irrigation Irrigation Total Tributary Mainstem in the Irrigated Projects Projects Delta Area Laos 35 61 - 86 N.E. Thailand 232 651 - 883 Khmer Republic 103 35 121 259 Vietnam 46 - 169 215 Totals 416 747 290 1,443 4.09 According to the Plan report, the provision of irrigation on this scale would make it possible to produce a large volume of agricultural products for expo--', as shown in the following table. Some 60% of the incremental rice .2-oduction attributable to irrigation (about 3 million tonis of milled rice) and all of the incremental production of other crops. is designa-.ed for export. Indicative Basin Plan Crop Production and Demands by Year 2000 Other Crops Rice (Paddy) (million tons of (million tons) Paddy equivalent) Total Production with irrigation 30.7 6.3 Domestic Demand 25.0 3.8 Surplus for export 5.7 2.5 Estimated Procluction without irrigation 21.4 4.8 - 28 - 4.10 As the first comprehensive study of the Mekong's potential for power generation, irrigation and flood control, the Indicative Basin Plan is to be regarded as a document of major importance. Its exhaustive analysis and comparison of a wide array of possible developments has led to the identification of a number of projects which clearly merit priority for further planning and investigation. Also. an imDortant by-product of the preparation of the Indicative Basin Plan has been the stimulus it nrovided for oroiect investigation and the collection and analysis of basic data. 4.11 There are certainly formidable problems to be overcome before international developmn+. of the Basin's tr resourrePq nlri coul become 2 reality - in fact, nowhere are these problems more clearly perceived than in the Mekong Conm'4. ttee and Secretariat = but +-h I not be allowed to detract from the value of the Plan as a demonstration of the way in .whi ch the M-ekon,g could be developed for -he mutual benef-it of the four riparian countries. 4.12 In the review of the Mekong development effort, the Bank found Ulhe InXdicative Basin Prlan tuo bue one of thle ch1-itef so-u-rces Vof inlfo r miav-on. However, a detailed review of the timing and sequence of project implementa- tion was rnot un'uertaken. since it -was realized that the Plan is to be regarded more as framewiork for future development (as in fact it is described in the *ub-title of thie report) than as a definlite proposal for project implementation, - 29 - V. DEVEWPMENT PERSPECTIVES A. Agricultural Development The Present Situation 5__n The Mekong Basin has a total land area, of ahout 64.5 million ha of which approximately 10.1 million ha is presently cultivated. Land usedf fo-r culAtivation of "r-ice +.he m.ain c-ynn anrl stanpl foodi of t.he ai" inhabitants, occupies about 8.6 million ha, or 85% of the cultivated land. Crops other than r ce, ocupyinabout 1.5 llion ha, are grown on the upland areas, the levee soils along the rivers, and on some areas of higher 41nA ;v V 6 h,-^ 1 - fl,mn nna A., n a; 4 ; 1 - , x, -nan ,. +n tha T.TO+ season (May through October). Dry season crops are grown only where Ulhtere JLs eas0y access LA to a pererJ"c;l. soLurce of walter. 5.02 `ne d nsce of rice nerfis of 'an' -use should not obe allowed to obscure the importance of other crops in terms of total production, exportJ earnilngs, farmer income and, not least, dietary :suypplements. W1tP.. the exception of plantation crops such as rubber and some specialized fruits, most of the diversified crop pr2'&uction takes piace on individual farms. Livestock breedir; , fishing, and the raising of poultry are other activities of farm families -vhich are by no means insignificant in terms of housenoLd. food supplies and cash income. 5.03 Annual paddy production in the Basin averaged about 10 million metric tons in the 1960's period. The average planted area was 7.3 million ha which represents a cropping intensity of 85% on the 8.6 million ha estimated to have been developed for paddy production. The average Basin yield is about 1.3 tons per planted ha. The highest yields are recorded in the Vietnam Delta and the lowest in parts of Northeast Thailand and Laos. 5.0o Crops other than rice which have significance in terms of exports are rubber (Khmer Republic), kenaf and cassava (Northeast Thailand), and maize (Khmer Republic and Northeast Thailand). In 1968, about 50,000 tons of rubber was exported from the Khmer Republic representing 30% of the value of exports. Kenaf and cassava were both grown on a large scale in Northeast Thailand for the first time in the 1960's. Kenaf production reached 650,000 tons of fiber on 520,000 ha in 1966, although the production has since declined due to uncertain market conditions. Cassava producticn reached a peak of 160,000 tons of roots in 1965 and has since stabilized somewhat below that level. Maize production in Northeast Thailand and the Khmer Republic ranges between 100.000 and 150,000 tons. most of which is exported. Fruit and vegetables are grown throughout the Basin and average annuanl prodncftion in the 196,3-68 perino was on the order of 1-6 million tons. - 30 - 5.05 With a present population of close to 30 million, the Basin is not over opulated in comparison with +mar.yothr parts cf "s Aia a 1 families account for nearly 90% of the total population. Farms are gr-------.eAlly larger tha.. Jin otaheir part 4of Souues Q^s4-1 She avrae- holding is about 3.5 ha in Northeast Thailand and about 3.0 ha in the Vi4er.ntane Pladiin T-h on± l I4y ara. ic n .I L L Laos fL.IUA-or wlUc" M.L±m.aLU.L UIL L Cis vLaLCabLe,. Smaller holdings of about one ha are common in the more densely populated pir-UV.LcesU"Z1 l of n r RpJUbL.L ariu Ihe VietUidiC DeJlta., bUt1' ui i4t less densely populated provinces average farm sizes are on the order of 3.0 ha. Oubside ofL whe Delta, tne majority of the farms have traditionally been owned by the farmers. As a result of recent land reform measures, owner- operated farms may now be more common in the Delta. However, more information about land tenure in the various parts of the Basin is needed as a basis for the formulation of sound agricultural projects and programs. 5.06 There are no projects in the Basin providing a dependable year- round supply of irrigation water to the farmer's field. In Northeast Thailand and the Khmer Republic, there are some run-of-river schemes -- diversion dams diverting natural river flows for use in canal systems. Some large dams and numerous smaller reservoirs, or "tanks", have been constructed in recent years in Northeast Thailand, but the water delivery systems are still undar constr _tion. A major reservoir project is under construction in t1_'e Miater Republ_c and a number of projects are at various stages of investi,ation and planning. 5.07 In the Vietnam Delta there is a long established system of navigatlon and d&ainage canals. The construction of sea-defense dikes along the coast to protect farmland from tidal inundation also dates back many years. Lately, work has been in progress to restore control structures on the canals and also to complete some new structures: the chief purpose of the structures is to prevent salt water from entering the canals during the low-flow season. Another recent development has been the introduction of low-lift power driven pumps for irrigating lands border- ing the canals. Prospects for Rice Production 5.o8 In regard to rice production, the picture is broadly as follows: Laos inmorts about 15% of its needs from Thailand: Northeast Thailand is on the average self-sufficient but wi-th fairly wide swings in annual oroduction: the Khmar Renubi-n eonnrted about 1q< of its nrodiction during, the 1960's; and the Vietnam Delta with 4o% of the country's population sncoiints for ahont 70% of the nntional vrodruc+tion- r5.09n VieOlds for raninfedA trasplnte pady hetyemost r%commoe%nly%n- g7^rown, range between 2.6 tons/ha in some of the Vietnam Delta provinces to less tha 1. tr./h- An parts ofP 'NTorsveast TM2ailand a-nd Laos Flood=ad_ap+ed -/L U±) -,c .4, j.a utCL %JJ * I.J I W,0L 14 .AL,,aJ.~ J.± IA 0±.L'. O 40 ..1 I: - .Lp - varieties grown in the Delta and around the Great Lake have yields between. a1.0 a.Ld 14.. ,/ . T14 High yie'dir.g vari et es bave been iJ. in A- - -A V4 - et na over the past three years. It is reported that over 300,000 ha were planted in 1970, most of which was in the Delta. Statistics for the 1970/71 harvest show a sharp increase in the Delta's paddy production, but the data do not differentiate between local and imProved varieties. The High Yielding Varieties Program in the Delta also involved widespread distribution of fertilizers at prices attractive to farmers. This is the only instance in the Basin where fertilizer has been used on a large scale for paddy production. For other areas of the Basin. the use of fertilizers and other chemical controls is negligible, 5.10 For the future a policy directed towards self-sufficiency in rice product-ion- would appear appropriate for Laos and Nor+heast Thailand. Geographically, these two areas are not well placed to compete in the world expVort market. Nor do +he ricelanr.ds offer the possibilities for conversion to other high value crops on a large enough scale to justify ir.port of rice. ForJ s.irl.ar reasons, ti.u self-suff cJ iency should be a minimum target for the Khmer Republic but, with a return to more peaceful c-444d4 -- -P--4 etfort shul be -,d 4orgi.- s - o .,4er e-o4 .LUL 1-ULA±LL VLV4LJ01, U-A .L'Us s [louJ.U LJe maUt=UV LA) C%L~~11 ± UJL LVI LILLO ",LF%J1 U markets. The Delta provinces of Vietnam will have to continue to serve as a ma 0UItr sr of rice frU I tIh reiLa1iUt;e Uo Ul4' cuntry, adU efforts should be made to resume exports now that Vietnam has again reached a position of self-sufficiency. Tne prospects for rice exports are not, however, 3ncourag-:ng at the presant time. In recent years, both prices andu Th'e volume ofI *orld trade in rice have declined as a result of production increases in countries which formerly were major importers. 5.11 The gradual upward trend in rice production over the years has been achieveci by bringing more land into production. With the possible exception of the Vietnam Delta in recent years, there has been hardly any discernible upward trend in yields. Data on land capability and present land use are not available in sufficient detail to form any firm conclusions as to the scope for further lateral expansion. Th* best approximations at the present time are that the ricelands could _e expanded by about 20% in Northeast Thailand, and at the most 10% in the Klbmer Republic and the Vietnam Delta. The scope for lateral expansion in Laos is unknoun but, with only 3% of the land area presently cultivated, there is probably some potential for further expansion. However, in all areas it may be safely assumed that new land brought into production will be increasingly of marginal suitability for rice production because of less favorable soils or topography, greater exposure to flooding, etc. Thus, incremental rice production through lateral expansion of ricelands is likely to encounter rising production costs. 5.12 In any case, beyond the next four to five years, the prospects for further gains in production by increasing the cropped area are by no means certain for most of the Basin. Therefore, programs designed to raise the general level of rice productivity in the Basin should have a high priority. Particular emphasis should be placed on measures to raise nroductivitv in the absenre of water crontrol; that is under rainfpd and flood dependent conditions. Even under the most ambitious development program. it would be many years before more than a small percentage of the nine million hectares of ri.celands could be served by irrigation and drainage systems. There are, of course. Dossibilities for nrovidinj7 supplementary water at critical periods of the growing season by low-cost diversions from streams and ponds. While thR nwmnhr nf farmers with access to a reliable water source is small compared to the total number engaged in rice cultivationn every effort should be made to improve the utilization of localized sources of supplementary irrigation so as to reduce the ri sk-S of rIned cdfaii use o-' mode-- inputs. 5.13 Lack of water control is certainly one of the constraints on the attain.ment of higher levels of rlce --ouciv., it 4is als the 4most- S 41 _4 c~ IvJ~ IJ~L.C 'J4 4J.LV,Ii. .L~ VUA.0i IJL I..LtV YV±IULLIk .L V.AiYy, 4. U ±,. a.L U l41: IiIUD costly cons-traint to eliminate. Moreover, there is no clear correlatior uet;vieen rainfdall andu yields. fur example, somrLe of th e relatively dury western provinces of Northeast Thailand produce higher rice yields than some of the eastern provinces wnicn experience nign rainmaill r1 nL 4 Most of the research so far devoted to rice cultivation has been irrigation-oriented. While such efforts should continue, there is a need for more intensive efforts to find out what can be accomplished under rainfed conditions. A constraint which has not received sufficient attention is the poor quality of seeds used by the farmers. It is the normal practice to use seeds held back from the previous year's harvest. Improved seeds, including both local varieties and the new short-stem varieties, multiplied under comnercial conditions with proper quality control, are no-t available to many of the Basin's farmers. A program of improved seed multiplication and distribution could be a major factor in increased productivity. Most of the new varieties of rice have been developed to produce high yields under ideal conditions with precise water control and other inputs. But it is of interest to note that in the Vietnam Delta such varieties have reportedly out-performed local varieties under rainfed conditions with only moderate fertilizer applications. The introduction of such improvements will no doubt be assisted by the fact that, with a rapidly increasing population, there will also be more intensive use of the already developed rice land, and decrease in farm size in some parts of the Basin will lead to higher labor inputs and more careful farming practices. Prospects for Crop Diversification 5.15 Most of the proeress to date in crop diversification has taken place in the uplands. Rainfed crop cultivation in these areas is confined to the wet season. Also. the areas whers soils arp suitahle for permanent cropping are limited in extent and, with few exceptions, are already in uSe. .Ynm.ples of continuous culti+Aion are +he rubber plantations in the Kampong Cham Province of the Khmer Republic, and the maize-growing areas %,J_8 t .orat L o. .-Me of Nr.+..e.as bI 4. d - 33 - 5.16 Kennf and cassava. which have come to be malor exports for Northeast Thailand in recent years, are primarily grown under shifting mnltivstion on nodzolic soils of low inherent fertilitv. After several crops have been grown the soil loses its fertility. If the soil is then left fn11w for a neri od of ten to fifteen yenrs, the nqt.13rq1 regenerationi of vegetative cover will restore its fertility. Shifting cultivation is 4n inpffiGiep+. u Of the lnnrl IAqo1,vQe sinr'o l +hnr 20'-n of the +.p n is occupied by a crop in any one year. It is also potentially destructiv' w-Then erosion cortrol i++m s nl-ea rwmAnd +.to p,I1 .ti4.Ta the land continuously. The rapid degradation of the physical character- lstics of th.e podzolic soils is such as too mi ;litate against the use of chemical fertilizers as the sole device for maintaining soil fertility. rrhVe so wuior to the - rbe, of1, shit:. -P-- -- I vati4on lies . 4g .r ±L1 OkJ..U51014 UVJ UJ..I J. L'L. LJIU1 0J± 013.LL I4LLS CL~LJ.IUVdAJ.L,J L ~. .L -" productive use of the regeneration phaseo This will require a crop rVtati.L systuer,m IInv0olvUie glra'ss cI-ops andI. WeS--,.s -wihil restore rather than deplete the so-i fertility. The inclusion of pasture in the rotati±on wO-,J ue .L.t- prcuit.abU.LLJaL)±e i. UU1L)JU WnU- I li-U'Z%. LL.LOULrng. 5OI7 There are large areas oI podzolic soilS in the Basin, but it is only in Northeast Thailand where they have been exploited on a large scale. Trials ouf various tec;ti.i.ques for maintaining soil fertility on fixed farm hold,.r.gs on the les- fertile soils should therefore have a high priority both foiL Northeast Thailand and the Basin as a whole. .5 08 Throughout the Mekong Delta, in Vietnam and the Khmer Republic, there are large areas of fertile alluvial soils which offer good possi- bilities for diversification in the dry season. There is room for further expansion of the practice of planting crops on the receding flood in the more deeply flooded areas, and in the Vietnam Delta the existing canals are a source of water for supplementary irrigation by low-lift pumps. Recently, encouraging results have been obtained with sorghum as an "after- flood" crop in Vietnam. In the lower reaches of the Delta, salinity control in the dry season would permit expansion of vegetable and fruit cultivation along the canal banks. 5-19 The levee soils along the Mekong and its tributaries could be cultivated more intensively for a wide range of crops, particularly with irrigation in the dry season. Particularly good possibilities exist in the riverain areas of the Mekong in the Khmer Republic. The lowland rice paddies of Northeast Thailand and the Khmer Republic offer few opportunit:ies for diversified dry-foot crops because of their poor drainage character- istics. There is, however, some scope for diversification on the higher fringe of the ricelands where rice productivrity is in any case low, - 34 - Prospects for Irrigation 5.20 Within the Basin there is considerable diversity in rainfall, hvdrologv, tonogranhv and soils. Hence. there is a similar diversity in the modes of irrigation to be considered for development. The follow- ing brnqod rpiv Aizr nf not.ntinlit,; qnrl nrhnblems is intpndpd qq n bhakground for the more detailed review of development priorities discussed in Chapter VT, 5.21 T.rge-scaler yeara--und ir gation from 1h.e rivers of Northeast Thailand and the tributaries of the Great Lake in the Khmer Republic reqrs lag *'.JLJto toJJ. L corQe¼~V' and *5L. the highly seasonal pattern of rumoff, and extensive canal system to distribute the stored water ove,r 4.-e 4rrgabl,e "an-Is. M. 4- re------re the m-I- - - ot.-- +ly - f-,-I,- m of irrigation development in the Basin, and can be economically justified only where there is an assurance of intensi-ve year-rour,d cultivation of high value crops. However, over much of the area topographically suited to irrigavuorI in Norbheast Inailaaiariu aurie the izQilflr Republic, uthe poor drainage characteristics of the soils preclude cultivation of crops other than rice, without substantial investment in drainage iacilivies. Since these areas already support a wet-season rice crop, the incremental benefits of year-round irrigation do not justify high cost irrigation facliliies. 5.22 A number of projects invoiving large storage reservoirs and canal systems are under construction in Northeast Thailand, and a start has been made on the first large reservoir project in the Khmer Republic. As originally formulated, the projects had the objective of providing year- round irrigation for intensive double-cropping with a high degree of diversification. It is now apparent that the transition from rainfed paddy cultivation to year-round agriculture will take much longer than originally anticipated. While considerable progress has been made in construction of the dams and main canals, progress has been very slow in providing effective systems for delivering water to the farmers' fields. It is evident that there are formidable social problems in superimposing sophisticated water control systems on existing patterns of land use and land tenure, and also in operating and maintaining such systems. These problems are now widely acknowledged and a more gradual approach aiming initially at supplementary wet-season irrigation is being considered. 5.23 The future policy for the western tributaries of the Mekong shouLd be concentrated on making more effective use of the dams and canals already constructed or under construction, and for the time being to limit project investigations to areas where the soils are suitable for diversified cropping. Experience with on-going projects will be an invaluable guide to the plannine and economic evaluation of direct gravity-irrigation from Pa Mong and Stung Treng. Until such experience becomes available, it would seem prudent to nlace a fairly low economic value on the notential for direct irrigation from mainstem projects. - 314 - 5.24 The eastern provinces of the Khmer Republic are thinly populated and soils and topography over much of the area are not favorable from the standpoint of irrigation. Investments in water control in these areas should have a low priority. 5.25 The well drained alluvial soils forming the natural levees of the Mekong are suitable for diversified year-round cropping under irriga- tion, and the first steps have been taken to develop pump-irrigation in Northeast Thailand and in Laos. In the Khmer Republic a form of flood irrigation is practised along the banks of the Mekong where the levee soils are suitable for a wide range of crops. Prospects for further development are good, particularly in conjunction with pump irrigation in the dry season. 5.26 The extensive network of navigation and drainage canals in the Vietnam Delta form a source of water which is alreadv being exploited by low-lift pumps. In the upper reaches of the Delta, these canals contain fresh water throughmout the vear; but n the lower Delta saline water enters the canals during the dry season. The potentials are good for f'iirthpr rdenvlpnmPnt. nf nw_-lif+. umpming. Thn miniymim dry qqonn flow entering the Delta is very large compared to likely irrigation needs, but anv deple+ion of +he flow by upstream diversions tends +t worsen the salinity intrusion problem. Therefore, upstream storage on the mainstem to provide lo0w-flow- au,g.entatio.n i'ec"mo" an "'a factor in. slta development. Agricultural Data Collection 5.27 In reviewing the present situation and in assessing potentials for future deUvelopm,lent, the Bank and i ts consultants found that there is a need for more detailed, accurate and up-to-date information on agricultural production, and land use. Each of the riparian counbries publishes annual statistics on agricultural production. Normally, these include planted areas, Yields and pIrodUctLon for the madjur crops, and in some cases harvested areas are given. Except for Laos, the data are broken down by province. Tne chief source of error lies in the estimates of planted and harvested areas which are obtained by compiling a vast Inumber of field reports of variaDie quaiity -- ciearly a formidabie task when millions of hectares have to be covered. Also, because of personnel and budgetary constraints, crop-cutting programs to establish yields are on too small a scale to cover adequately the large areas and wide diversity of conditions. The problem of delineating and measuring areas devoted to major crops is reflected in the lack of up-to-date information on land use. As a consequence, only the broadest correlation is possible between the present land use and the different soil types (mapping of agricultural so'ils to a small scale are available for Northeast Thailand, the Khmer Republic and the Vietnam Delta). 5.28 The existing soils maps have formed a basis for various studies of land capability, notably the EAR! Atlas, the work of Development & Resources, Inc. in Vietnam, and a UlTDP supported program in Northeast Thailand. However, an urgent need exists to obtain sufficient land use information to superimpose present land use patterns on the land capability maps. If this were to be accomplished, the scope for lateral expansion of cultivated areas could be more accurately assessed. Also, much has yet to be learned regarding actual field experience with individual crops and cultural practices under various conditions of soils and water regime. 5.29 In a large measure, the critical gaps in land resource data is a result of the various agencies engaged in data collection having to rely largely on field inspections supplemented by out-of-date aerial photography. Major advances in the quality and detail of land resource data could be achieved if these agencies had at their disposal more modern techniques of' photography and remote-sensing from aircraft and earth satellites. The economic and technical feasibility of land resources survey from aircraft is well established, and the first earth satellite specifically designed for earth resource surveys is planned for launching in the near future.l/ One important advantage of an earth resource satellite is that it provides coverage at frequent intervals -- about once every 15 davs in the case of the Mekong Basin, It is to be noted that the Mekong Committee has endorsed a proposal for particination in the ERTS program submitted to NASA by the Engine!er A-ency for Resource Inventories, U.S. Army Corp of Engineers. This proposal calls for acquisition of satellite sIurvey data for the Mekong ;,asin. B. Power Development Power Demands 5.30 In 1970 the combined power consumption of the riparian countries ifas about 1,000 W ar.d e.ner5-r generated waapp.oxi.ael r,000 SVW.. Thailand and Vietnam, the two largest countries, accounted for about 75% and 20% respectively of the rpoer and energy generated. An=ual growth rates in power consumption in both Thailand and Vietnam are presently above 20% and, in the past, have been hiher == durin.g the 1960 's Thailand's growth for several years reached 30%. In the Khmer Republic nvnd T-^a ch- -s,4~ 4... A-4 on4 Js, 1 a ' ...2. 4 13 Z. s 4. -- tJ a T-AOS~ . thaih AJ-&- -ra.int ^ en.ergy cons.ump i Lo L LL Lof.LLL.L'.LUU U.JL facilities, but as this constraint is removed these two countries could also have 1-11;gh g .v W +14 rates Jn deman.d. 1/ Th;Ie first Earth- Resource Techn,ology Satteli tw nERTS A" is to be launched on April 1, 1972, by the National Aeronautics and Space Admi1Unistration of the United States Government. Tne Priority Program outlined in Chapter VIII includes a recommendation for instituting a progra-m tD take advantage of tne ER-TS program and other techniques of data acquisition and analysis. 5.31 According to the load lorecasts used by the Mekong Secretariat ill preparing the Indicati-ve Basin Plan, the generation requirements of the four riparian countries by the year 2000 would reach 129,000 GWh and 24, w,0 NW - or twenty-four times the present requirements. Thaiiand (64%) and Vietnam (29%) would between them still account for most of the demand. The major load centers, which lie outside the Basin, are Bangkok and the Central Provinces of Thailand, and the Saigon-Cholon area of Vietnam. 5.32 The demands for Thailand adopted by the Secretariat were close to the highest of three "Moulton" forecasts prepared in 1966.1/ The power authorities in Thailand are now using the "Moulton B" forecast which was also used by USBR in their evaluation of the Pa Mong Project. For Laos, the Secretariat adopted the forecast prepared by Electricite du Laos; this was also adopted by USBR. The Secretariat's forecast for the Khmer Republic included a large block of power for an aluminum complex, to be constructed in 1980 in conjunction with the Sambor Project. For Vietnam, the Secretariat's projection postulates a three-fold increase in, generation between 1970 and 1975 (average annual growth rate of 25%) in recognition of the pent-up demand which presently exists. Thereafter, growth rates decline from 16% (1975-80) to 8.5% (1990-2000); in the early years this is similar to the pattern of growth experienced in Thailand. 5.33 If the "DMoulton B" forecast for Thailand is substituted for the figures used by the Secretariat, and the special industrial load for the Khmer Republic is deleted (so rz.2at the projections do not reflect pre- determined assu Iptions as to fuvure development), the nrojections for the four riparian countries would be as tabulated below. Total Generation Requirements Thailand, Vietnam, Laos, Khmer Republic Average is-uuea'l Energy Power Growth in Energy (Gwh) (14Wltw) Demand iy70 5,000 i,000 15.5% 1980 21,050 h,2h015% 1990 51,100 9.780 8.6% 2000 112,250 21,240 8.1% 1/ "Thailard Electric Power Study" 1966, prepared by a team headed by J.S. Moulton under eontraet to 1J!ATD - 37 - 5.34 In rapidly expanding systems there are inevitably considerable uncertainties in any long-range projections of power and energy demands. However, as a background for considering alternative forms of power system expansion, the projections listed above are not unreasonable when compared with experience in other developing countries. Annual growth rates are projected to decline from the present high levels exceeding 20% to about 10% in the early 1980's and then level off at about 8%. It is to be noted, however, that a steeper decline in year-to-year growth rates in the next five years could result in much lower long-term demands. Sources of Power 5.35 In the Indicative Basin Plan, a proposal is put forward for meeting virtually all of the growth in the power demands of the riparian countries in the period 1980-2000. 5.36 The five mainstem projects in the Indicative Basin Plan, with an installed capacity of 21,700 MW and an annual energy generation of 116,000 GWh, would develop over 90% of the hydro-electric potential of the nainstem of the Mekong. 5.37 The other major project in the Plan, the Nam Theun Project (2,500 MW and 89oo0 Gwh). is the largest block of nower which could be developed at a single site in Laos. This represents about 20% of the notential of the T,L,atian tribhtaries assessed in a reent ridk studry bv the Secsretariat. The power po'tentials of 58 possible damsites on 14 river basins were estiiteid hut, excep.t fnr 1N\m. Theun, none of the nrnocfts has a capacity of 1,000 MW and nearly half have capacities less than 100 mi. 5.38 In Vietnam, hydro-electric projects which appear sufficiently attractive to warnrar.t technliical stu-deies hnave a -ptenti a bout n1 ,, ' WT, of which about 1,000 MW is in the Mekong Basin. By the end of the 1970's virtual G.ly~L. '.~'- alll f te he ic "a" of± ' hailnd J.ill. have bI--- developed. The hydropower resources of the tributaries in the Khmer Repnublic are as ye+ ureploi ed, bu+ the total potential is only 300 to hoo MW. 5.39 Sources of fossil fuel within the Basin countries are small in re~.L 0.U.LJ1 UV C2.1 .L-..LjidaU". £IUL li1l .LU1-V UVJUWJ 1' ~ d~LJ1 ULLLI t%&AjJL Uid..LU. in off-shore areas may yet lead to discovery of oil and natural gas. Thailand has a mLaJor progra.,m under way for construction of large oil-fire< steam plants using imported fuel in the vicinity of Bangkok. Units of 300 rlW have been installed and larger units are being planuled. Vietni1am also is planning to construct oil-fired thermal plants in Saigon and the Mekong Uelta. Thrroughnout Lute Basin many communities are dependent on small diesel-powered generators. 5.40 Experience in the USA and Europe has shown that, with unit 0; 00 ha.+,Ti0on Oflf ~nr I 1IA M¶T nta ~% Ian, - wrm.rh bana,nac co,na-..p +- 44 ia -4 4-b, s-zes betT.-zeen ,°00 ar.d 1,100 11.JS nr.ulear power U.b.re U V V Vit wI.h thermal power. Some technical studies of nuclear power have been made in Th.ilal.d,A th-ae or.ly n ,l ,4ie.- l k14-- + be ---arge, e 4-g -ia,44- ~~ ~ ~ . iJS4V na.d.JJJ UY.~ LV~L..L~ U VVU 4C.01. v U1VAUJ. - yuLIL1, integration of large nuclear power plants before the 1990's. Basic Considerations in Power Development 5.41 Comparative analyses of hydro-electric power from mainstem projects on tne Mekong and thermal power generated close to the main load centers have been made by the Secretariat and also by the Bank's consultants (see Chapter VII). These analyses show that Mekong hydropower is competitive with thermal generation and has the advantage of long-term savings in foreign exchange. But, on the basis of present information, the early hopes of Mekong planners that hydro-electric energy would have a marked economic advantage compared to thermal energy would not appear Justified. However, a definitive assessment of the comparative merit of alternative sources of energy will have to await a more comprehensive assessment of project costs and benefits including an assessment of the ecological impact of the proposed major storage dams. 5.42 Exploitation of the Mekong's hydro-power potential would require a high degree of regional coope:ation in power system planning and develop- ment. With two exceptions, the major possibilities for hydro-electric development lie outside of the two countries -- Thailand and Vietnam -- which will be the main markets for power and energy. The two exceptions are the hydro-electric potential of the Central Highlands in Vietnam and the Pa Mong Project which lies on the border of Thailand and Laos. An approach to development which would permit the four riparian countries to share the hyclro-electric resources of the Basin could have considerable merit in view of the scarcity of indigenous fuels. Furthermore. in the case of Laos and the Khmer Republic, power development for export to the other rinarians could m;ake a significant cnntrihuntinn to the onnntriesl foreign exchange receipts. However, major investment decisions must necessarily be consistent with national policies for nower develonment. and dependence of a national power system on power and energy from plants located bevond thn national boundaries- is .wri1nel aknckinwledged as one of t.hA major issues to be faced. Until recently, the international aspects of Mekong hydro-elertric rovel^rpment could be corQidered orly -in ger.eal terms. But now that more information is gradually becoming available about the pnoten+tiail of +.hi e-nn .m,,r prt,e.ct ar.di +E.ircstsQ ar.d hgzrInffJt, a basism .rzill soon exist for the governments and agencies involved to establish more definiite -vi ews- a o the poiie ovrin evlpmn o -b sn power resources. 5.43 So far, this discussion has been primarily concerned with the lo-=te-I- prspct of-ydr-poe A-velopmer. fom .,ilsem oeCts. UVJS v.LII& jJ.L Javv~ UD VJ.L LLJ'..k1.iJ~JVUW0L I.LVULJJ-VLUMJ1U fr U1I mni nstek1O U± j. VJ±uJ~.L There follows a brief review of the near- to medium-term outlook for power' devvelopm.en.t in each of Uhe riparian countries, t with pardic-ular reference to areas within the Basin. - 39 - 5.4h The growing demands for power and energv in Thailand will be met by the construction of oil-fired steam plants near Bangkok. Northeast Thailand was recently connected to the Thai Dower grid which serves all of the country except for some isolated areas in the south. Formerly dtpendent on a gas-tufrhinA_ several hvdrn-nLants subject to wide qeasonal variations in output, and numerous small diesel plants, the Northeast can n__ hw beasiivred of a more reliable anri adenqte werp snpv_ The I\nm NMmirn project in Laos is also connected to the Thai power system, and Thailand has agreed to purchase enrergyr in excess of requirements in Laos. 5.L In -7etm a+nirVwril be gier to rei- -> cout r' Ti. 1U4 -+ .,++n,+4 ,-"v -.4 I I ~ V r%- " +rn s -nn 7 ,*, ~ rrIr+wT f L.UJSZI, 0' l, +S I &n J.n..V'aS U'SaAJ.4J±5 jl~ ~i4~'SJ large hydro-power potential, to providing additional thermal generating capacity ir. LAI; Sa%LGigo areaC, Cand toJ p.Lrogressive Lintegraion_%J. of. theIU IIW,erou independent systems. Plans are well advanced for the first thermal power t be instd.L.Leu in Vile Del J.LaI ardu LUu.IaRU p.LWuns cal..l flr interconUnecvt.II with the Saigon system. 5.h6 Recently, one major hydro-power project on the Nam Ngum, and two smaller hydro schemes have been placed in operatiobl in Laos-. Tere is considerable potential for further development of small hydro-power projects near the chief population centers. Tne magnitude oI the demand in Laos and the distance betweer. load centers are such that no advantage would be gained by intrco-rnictio-.i Hy*:,o-power d_velopr_ent to m-et local needs should have a higr priority in Laos because of the high freight costs incurred in tran,sporting fuel from Bangkok, the chief port of entry. 5.47 A numbe-: of multipurposa projects on the tributaries of the Great Lake have been investigated in the Khmer Republic. The plants generally have low annual plant factors, are subject to seasonal variations in peaking capability (because of changes in reservoir levels), and would be subject to certain constraints on operation imposed by the need to meet irrigation requirements. Also, the projects are in need of further investigation following collection of more hydrologic and topographic data. Because of the long lead-time needed to establish the economic viability of the multipurpose developments, a strategy of increasing the thermal capacity of the system appears to be indicated for the near-term. Although this would involve higher fuel costs, the capital investments wouLd be much lower. With further investigation some of the hydro-electric projects might be found to have a useful place in a largjr system. - 40 - VT IJIATTON.AT, TlVET,nP?4.rKTT Or T.A\n M WATFR RRqC)TMr.P A. General Considerations 6.01 Consideration of the development of the Mekong Basin is rendered more cormplex 'b t h fac that m 4 +te;r- o f fo c'1 Cr "" are involved and that for two of them, Thailand and Vietnam, the 4te ..tori-es -wlth;4 +1e Bas-4- con.tut 4r-v a+ pt- 1ei o UI.L .L ..U'J. ..AL J VVJ-I..LL LMJJ LL, UCLQJ.LI ~A L& ; LJUIA UAJLL. d. kJdJCI . L U J± IL... uLJULoI national territory. Even if the Basin lay entirely within one country, prUoblerms of prior^ity and allocation of rsUurces, of locaL 'iterUests and of political balance would arise. The history of major river storage schemiies bears amnple testimony to the ific y of btcu-urg an acceptable allocation of costs. Such difficulties are particularly evident when, _, _i OU1 1 1UI CatWs _U 1OTi all CUTUDne I1 CCn,9UU_JI _ as; is often the case, the costs and disturanlces of constru>ctilon ares concentrated upstream where the most advantageous sites for storage and power potential are found, while the major benefits lie downstream or in urban centers outside the Basin. Within a single country, adjustments in national financial assistance can help in finding a solLtution. Between two cr more countries, the finding of an acceptable solution is inevitably more diffricult, though it is possible that international financial assistance, where available, can play a catalyst role. 6.02 The benefits of cooperation between the riparian countries in the development of the Mekong Rasin have to date been discussed largely in terms of total estimated costs and benefits of the proposed mainstem projects in an integrated development of the river system and with reference to agreement on mainstem low-flao water use. These certainly constitute a most important aspect and the desirability of regarding the river and its tributaries as a total system from the beginning can be fully endorsed. Qnly in this way can benefits be maximized in relation to costs and the international difficulties often caused in other river systems by isolated, independent action be averted. 6.03 It is not infrequently suggested, on the other hand, that because the four national territories of the Basin are so dissimilar and because priorities for their development must be determined in the contexb of national planning involving non-Basin territories and their problems in the case of Tlhailand and Vietnam, the major emphasis should be on national approaches to development of the respective Basin territories. The four component territories differ substantially in physical conditions, in ethnic groups, in population density, in degree of integration into commerce, in transport facilities and in education levels to mention only a few of the important considerations for policy. It is indeed for this reason and because of the need for a national perspective in determining priorities, that the Bank's review stresses the desirability of con- sidering separately the potential of each of the four component territories of the Basin. - 41 - 6.04 However, the national and Basin-wide approaches can be regarded as strongly complementary. Apart from the mainstem projects, which directly affect more than one riparian country, joint riparian efforts can be of great assistance to the sub-basin's development by economizing Basin studies and expertise, in communicating relevant experience, in preparation of agricultural projects and in organizing financing and tecnnical assistance. In current conditions in the Basin, shortage of expertise and requirements for training appear at least as important as shortage of finance. 6.O5 Moreover, it is only by close interaction between the national and Basin annroaches. that the exnerienme in the develonment of sub- basins can contribute to the evaluation and design of the major projects, At this noint, in time nnd under the previling nolitial econditions in the region, it appears that the four riparian governments are still striirng to gain n clenr understanding of hm. the iovnt miitinir7no5 development of the Mekong River would compare with alternative develop- ment. on nat+.ionnl tnrrioryr when i+. wouildl -reome ec-en+;Ial +.t intrP._nq the support for regional cooperation in order to further their respective national devrelopmXent go -s. It is therefore essent a That both project- oriented basin and national planning fill in some of the major information gapns e-^A lead to - cleae pereptor -+ --A cot-Ld 04P+s o^ e_n development by the riparian governments. It is in this context that the fo"l or.-crg c er~. n..n nr. srm ate.ly,- th l.d-- .r -A -4-. A-lopmenr.t -~ ~ ~ '.-X.Xy V~A J. ' L. L %JiA . -Ld. O Q%a aC . U%,.L.J UAJ.L .6..L. " ..MAJ." VYGL.U~.L U~ V ~- JAI1p U potentialities of each of the major component territories of the Basin. B. Laos 6.06 itwLh tha exception oI the much-studied Vientiane P1Lain, there is a lack of reliable information on land resources and agricultural productiont Ln Laos. From the iimited data availaDle, it appears that the land cultivated in any one year is about 700,000 ha of a total land area of 23.2 million ha. Annual production is on the order of 500,000 tons of paddy rice, 100,000 tons of upland rice, and 180,000 tons of oite. icrops k IuLL y cernf Iruit and vegetiabies). u.0 Distance and topograpny, as wae±± as the disturbed. po±iiX3caJ. situation, are barriers to the movement of agricultural commodities in Laos. For nmny of the river towns, it is easier to trade across the Mekong with Thailand than with other areas in Laos. The balance of trade in agricultural produce is presently in favor of Thailand, and it is estimated that Laos imports about 50,000 tons of milled rice annually. 6.08 IT part, the need for imports may stem from local deficit areas being created by an influx of population to the security of the river towns (Vientiane alone accounts for half of the rice imports). A contri- butory factor, however, could be the close ethnic ties between merchants on both sides of the upper reaches of the Mekong and the incentives - 4- created by consumer goods being available at lower prices in Laos than in Thailand. Thus, Laos' trade deficit in agricultural produce could conceivably be due, at least in part, to the marketing medium rather than low procd.ctivity. 6.09 Laos is unlikely to be able to export rice because its neigh- bours are likely to be self-sufficient and the country is far removed from the chief ports of the region. Therefore, the policy for rice production should be aimed at reducing imports and achieving a sustained growth in production sufficient to keep pace with a growing population. With a present population of less than 3 million, and less than 3% of the total land area under cultivation, and with ample rainfall over most of the country, the goal of self-sufficiency should be well within reach if there is a return to more peaceful conditions. 6.10 The potential for diversified crops is good, but again the export prospects are distinctly limited, except perhaps for crops particularly suited to conditions in LaosO Fertile levee soils are found along the Mekong near some of the major river tamns, and upland soils of high fertility are found in the high rainfall area of the Bolovens Plateau. The levee soils and the Bolovens Plateau could be cultivwated more intensively during the wet season than they are at the present time. 6.11 Considerable attention has been given to possibilities for irri2aeion develorment in the Vientiance Plain. Planning studies have led to the identification of eight irrigation projects with a combined area of 33.000 ha. The water supnlv fnr these proniects wumld be obtained from central pumping plants on the Mekong and Nam Ngumi. Flood protection dikes along the % kong nnnd ra Nnm. mm are inclullded in the prnposed plnnsn Construction of one of the eight projects will begin shortly. This is the Tha Ngon PronJect (800 ha) which 4-i bei s ppnrIved hyr 'vhr Asian. Development Bank, and the Overseas Technical Cooperation Agency of Japan. Two projects. the Hat Don Keo Proiect (6-On hn) -- nlso knwn ns Casier Sud -- and the Tha Deu Project (1 ,900 ha) are included in the Mekong Coimnittee 's Pioneer Project Prograrnm- So-n- of these pronects maylv provre to be economically feasible because of their proximity to markets and +he genernlly anoo 7oils. Thejr constuctionr nd operation sihorl - vro4e an opportunity for personnel in variaus government agencies to gain Pynp.eriw eno inn1 iphncam of' irigt-+Aed gr: nt- v 6.12 Ou.tside of the V4erti ,.e Plain there are reported to be numerous small dams and pumping schemes, but the only large project is the Nam Tani DPoject in NorThe4 Laos T - c--'--4--4-' b- the Roy a Lao Govern-ment with the assistance of the United States Agency for International Develop- 11L'4LVO J.1LC PJ.'WJCt V U C1I UX_9VVL-DV .4.L U.d.LL WdlL a U I.Wulc )S' LYo ut1 UUb g iluZU to serve about 6,000 ha of land. This project should provide experience :. design and operation a-nd serve as a forerunner of further gravity irrigation projects. - 43 - 6.13 Land and wnter resource investigations in Laos have in the past been oriented toward irrigation development. More emphasis should now he nlaoed on agricuitrnal smrviyvn of areas which Gcnild be sourres of supply for the main population centers. Such surveys should include cvrn invr.nt-vr-i m.. 1 nnr1 q+.tidin nnrl qenil qirwr' V,_ PIr4.in'r qhrnil t'1 be given to identifying production possibilities under rainfed conditions. This doss notv .mean t-hat possibilities for irrigation^ should be ign-ored, but they should not be pursued at the expense of other forms of development. 6.14 Construction of the first stage of the Nam Ngum hydro-electric k'~'-'J'-- " -' .'I-' J,WL VhJ JA L '4 V _~ IUJ..vlj.~ JLC ± V4LV., LJUUJLA UV"..L ~ 4 initial stage comprises a concrete dam and spillway, and a powerhouse cos4.;n tr +-Ie-sTI/5T.its -44 .e MU- c sdeise o e--lt h - UL±L6 UUJI.J I_-.JIJkV U4LLU~ JO* .LLJ. jJ.L 'JJUk; LO) UIvO.L6LItZU UVJ yu.JLZ±IUU LLLIU ±UUU.L" installation of spillway gates and the extension of the powerhouse for th"ree additional 3 i_ Vunits. First pUwer is expec,ted to be gener-ated early in 1972. An agreement for the sale of energy to Thailand has been regotiated. ,A *ipot-ant featue of t,he Ml ait Ngu,in is itS potential for increasing the dry season flow in the Mlekong once the spillway gates are inSUtaled. Thi1s lw-flow augmentation couid De significant in relation to downstream uses in the Khmer Republic and the Vietnam Delta. C. Northeast Thailana 6.15. Out of a total land area of approximately 17.0 million ha in Northeast Thailand, between 3.2 and 3.7 million ha are cropped to paddy and dry-foot crops in any one year. Rice is the main crop, but there are fairly wide year to year fluctuations in cropped area and production which appear to be due to climatic conditions, particularly in the amount of rainfall at the beginning and end of the growing season. In the period 1960-1968, the average area planted to rice was 2.6 million ha, the average production was 3.1 million tons, and the average yield per planted ha wras 1 .2 tons/ha. Thailand is one of the world's largest exporters of rice, but the Northeast region is believed to be mainly self-sufficient neither contributing to exports nor importing from the rest of the country. About 75% of the Northeast's production is glutinous rice for which there is limited export potential. 6.16 Other important crops are kenaf, cassava and maize. The world market for kenaf is closely related to the fluctuations of the world jute crop. As a result of shortfalls in the jute crop in 1966, exports of kenaf from the Northeast reached a peak of 650,000 tons. Production has declined since then and in 1969 was about 319,000 tons; however, a large area is understood to have been planted in 1971. Cassava, another export crop has shown rapid growth in the 1960's with less fluctuations than kenaf. Production of roots range between 110,000 and 150,000 tons, but the Northeast accounts for only, about 6% of Thailandis production. Most of the maize production takes place in an area of fertile soils lying to the west of Korat. Production varies between 100,000 and 150,000 tons, and represents about 10% of Thailand?s exports. 6.17 Given the limited export possibilities for rice, especially the glutinous -variety, the policy for Northeast Thailand should be to diversify agricultural production while maintaining self-sufficiency in rice, The available information on land capabilities indicates that 3.3 million ha which is presently in use for rice (on the average about 80% is planted in any year) could be expanded to about 4.0 million hae Thus, over the next few years, rice production could be increased, as it has in the past, by bringing more land into production. But in the long run, higher levels of productivity will be needed to keep pace with population growth. Therefore, a start should now be made on programs designed to bring about a general increase in productivity, particularlv under rainfed conditions Another source of increased production is the 200.000 ha of land which could be served from existing reservoirs. 6.18 Average npaddv vields for the fifteen provinces of the Northeast range from 2.6 tons/ha to 0.7 tons/ha. An essential elerment in formulating a nrogrAm to Ps:ist the fnrTrr.r in imnroving nrourcitivitY qhourld hbe _ thorough investig'ation into the reasons for the wide variations in yields between nrov-innes. These vnrintionsr caninot. be eP-rnined in terrms of rainfaLll For e:aample, the proince of Ubon which is the largest rice producer has nmple rinfanll but a low average yield of abo1i+. Cu tons/ha. 6.19 A afnitl orf r%-1vI nnA c b t -Pfe 7v N .e m1-Tl'4 r l.d shvrf that about 3 million ha of land in the upland areas can be considered as si 1tahvle for cJ-fo rop-s. T+ is 4 these areas -here 4h rpd 1-t in kenaf and cassava cultivation has taken place. The problem in these areas ;-L th-e Adec-L-nee -n so-1 fe"+A; ;+Tyrh.c 47- olkPelr-y pv%V%iled-="5^ cultivation of the same crop. The land can be cropped for two to three years T If natu reaenlrat o- of forest cov-er is depended on to restore soils fertility, a fallow period of about ten years is required. Under a +-- c4t rot-4-ion of 4-ee -Iar 4uQ-4rto ar.d ten year- -- 4l, it 4 0.444 J.. ..WVC.U.lJ- IL U4L"~ JUC"J. % ..L-U4. LVakL JL5L WuLk LS'.l1 YUCL.L- ±d.L.LU'JW, .LL would be possible for about 0.5 million ha to be cropped annually. How- e.. VI., ULere± is . v at.0 least 0.1 5 r,:'lJIiorL0. hLJa u.Lru.L cl-oU at pau J rL,tLI and the cropped area has increased every year -- a trend likely to con- U.LLLU.0 W.LUiL 0 CL &LUVJ.".6± VVUk "U..Ld±L±.* ±4.L U4itV I.Le-1U L U IULUILLI.±¶.LtjU, UIIU agricultural potential of the upland soils could be exhausted, Controls on, forest clear-ing are a,lmost -Lpossible to enforce, therefore the solution lies in encouraging the farmers to adopt farming practices which, Un their oUn interes Wtl stabi1 -lze cuJltivation oI hne uplanCs Such practices would involve rotation with pasture or other grass crops in comrbination with improved soil and water conservation. 6.20 Six large reservoirs w4ith the primary purpose of irrigation were constructed toward the end of the 1960ts. Work has been concentrated on construction of the dams and main canals. Progress has been slow in developing the distribution systems. WThere systems have been provided, they have served to demonstrate that the problems of ilm,lementing yrear- round irrigation for multiple cropping are more formidable and more costly to solve than was orizinally assumed. The Bank's review of the situatiorn leads to the conclusion, which now is generally accepted, that a step-by-. step approach should be adopted. The first nrioritv is to construct systems to provide a reliable supply of supplementary water for the wiet- season rice cron. As exrperienee is gained hv the operators and the farmers, opportunities will develop for dry-season irrigation. The nroiects as orig nsllv fermml,twl wmlrl q ser-p abhrot 200F.lnOn han. fpuern-lon... ment in the next few years should be concentrated on about 40,000 ha w.there the mn C&.als have alredy beenr construc+,A - T-, then, canals are in need of repair and modification. Immediate attention shoQlr'ml A be giento th-.e _or ' -a,, o det -P41 ,-.A for i- igation of the remaining 160,000 ha commanded by already existing storage dams. Do MI- M-- D-1,14li I:V.L lacu'y Yt;U -J U .lmX; IU.UI .L- "V IUU JJ..LA- ito U:.- -LrU M S . u 6.21 Fv- manry years the Khmelr- Rep-ublic has deri-v-ed most of its foreign exchange from the export of agricultural commodities. Until 1969, . ce produ_ts (mIled r;I e and rice loEur) W-,te runuing at levels exceeding 250,00: tons and at times reaching 500,000 tons. Rubber and .L _l _ , . - . . . I I I uo a lesser ex=ent -siaize nave also been iaportant exporT cropse Altnougn. recent data are not available, it is probable that communications have bueen disrupted 'by nostilities and this has caused a sharp decline in exports, 6.22 Of the total land area within the Basin of 18.1 million ha, sorme .3.4 mlli-on ha are in use for agriculture. Ricelands occupy about 3.0 million ha but on the average only 85% is planted to rice in any year. The patterns of rice cultivation follow closely the varying hydro- logic conditions that prevail throughout the region. Of the total rice crop, some 70,5 is planted to various forms of rainfed paddy and the remaining 30N is cultivated as flood-dependent varietiese Annual production of paddy averaged 2.*6 million tons in the 1960Is, with a mean overall yield of 1.1 tons per ha. The total area under crops other than rice is about 400,000 ha. Rubber is the most important perennial crop occupying 60,000 ha. Production of fruit and vegetables on a similar area approaches 600,000 tons. Maize, grown on 125,000 ha is the most important field crop. - 46 - 6.23 f tothe0utre , the thie Pwpublic sh1'1 A n difficulty in meeting dorestic demands for rice in view of the large surpluses h-uat have been achieved in recenrt years, However, if the external markets are regained with a return to more peaceful conditions, the challenge wili be to service these markets at the sarne ti,Mie as increasing production to meet the needs of a growing population. This challenge could be met by a modest overall increase in the yields oU.° paddy grown under rainfed and flood-dependent conditions, and it is to this end that the main effort should be directed. Except for completion of the on-going Prek Thnot project and rehabilitation of the Bovel project, further large investments in civln works witn the primary purpoe of rice production does not appear justified. 6.24 A number of multipurpose projects on the tributaries of the Great Lake have been investigated in varying degrees of detail. Tne Battambang Project and the Stung Chinit project have been studied in some detail, wdhereas studies of other development possibilities have not advanced beyond reconnaissance grade. The Battambang Project seems to deserve priority in further studies because it is located in an area where soils are suitable for diviersified cropping and flood control benefits may prove to be significant. In its present formulation as a multipurpose project including a dam, power plant and dowmstream diversion dam, the project has a low rate of return. Alternative project formu- lations need to be examined including the possibilities of constructing initially only the diversion da-m to serve a limited area. In the case of the Stung Ch:Lnit Project there are also a number of economic and technical aspects of the project, as currently proposed, which require further study and analysis. 6.25 There are good prospects for expansion of diversified agriculture in riverain areas of the Mekong where a form of flood irrigation is practised for manv years0 Narrow channels - -anion locally as "preks" are cut through the natural levees to admit flood w¢aters to the river- bank farms. With low-lift pumps to provide supplementary water, more intensive and varied dry-season cropping would be possible. 6.26 Possibilities for lowv-lift pumping exist in the upper reaches of the Hekong Delta. particularly the Prey Veng province on the left bank of the I-ekong. A large number of shallow depressions or "bengs" are found in this area which retain water on the receding flood. Studies should be made to determine the possibilities for replenishing the water in the "bengs"f dnrina the drv season. This area has a reasonably pre- dictable water regime -- the area is flooded each year but depths are low enough to permit culltivation of siTngle transplant naddvy. As a result, the farmers in the area have shown some interest in the use of fertilizers. - 47 - _, ^--- on z.1- left __-7l of the __knng be+ -- thAore wt To and the Delta, is relatively undeveloped and soils and topography are gnrl1y +*w At +rr.-4 rw T't" r-z n i I rTi r+.h nrd1 C6,sf1;- L W4Lh--.4.L ho u efler Ua V_ aI.A.f _--- J__ __ _ potentials for diversified farming in the Ratanakiri province, which are relatively ;ne-e-e t^cus ofre rrm+lo-i E. The Vietnam Delta 6.27 The sixteen Delta provinces of Vietnam cover an area of some 3.o million ha. With a population of appro)d .iatel- 6.8 I, llion, orr h% of the national population, the Delta accounts for 70% of Vietnam's rice production. About 1.9 miilion ha of soils has been iuentified as Ul ti- vable. The area planted to rice each year averages about 1.6 million ha, and about 15~0,000 ha is planted annually to non-rice crops (chiefly frLuts, vegetables and coconuts). Thus, an additional area of about 150,000 ha of cultivable land remains to be brought into production. About one million ha of land is unsuitable for cultivation; this includes the acid-sulphate soils of the Plan of Reeds, the peat soils of the U itinh forest, and the saline soils along the coast. These soils would be difficult and costly to reclaime 6.28 Three systems of rice cultivation have developed in the Delta which are adapted to the seasonal water regime. Floating rice is grzmm on aboutx 500,000 ha in the more deeply flooded areas in the upper part of the Delta, In the less deeply flooded middle Delta, a system in which the rice is transplanted twice (apparently as a form of weed control) is practised orn about 200,000 ha. Single transplant rice is planted to about 900,000 ha in the areas which generally are free from flooding. Average yields are on the order of 2.6 tons/ha for single transplant rice, 2.0 tons/ha for double transplant rice, and 1.- tons/ha for floating rice. Average paddy production over the period 1959-1968 was 3.3 million tons, but sharp xicreases in production have been reported for the 1969/70 harvest (3.'93 million tons) and the 1970/71 harvest (4.39 million tons). This increase is attributable to the widespread introduction of high- yielding varieties. In 1970, about 320,000 ha were planted to new varieties in the Delta, mostly grown under rainfed conditions in the lower Delta but some dry-season cropping using lotam-lift pumps took place in the middle and upper Delta. Government officials in Vietnam are of the view that the country returned to a condition of self-sufficiency with the 1970/71 harvest, and are optimistic of further gains in production. 6.29 The Vietnam Delta has some important physical aspects: large tracts of developed paddy lands intersected by a long-established network of navi-ation and drainage canals: floodine which is predictable and only infrequently damaging; a supply of water for dry-season cropping in the upprer and minddle reanc.htno. h n +h elt nd nn established water - 148 - transport system connecting the area to a large domestic market as well as outlets for exporto -Thus, despite some constraints such as salinity intrusion during the dry season in the lower reaches of the Delta, inadequate surface drainage in the high raimnfall areas, and in the longer- term a limit to the availability of dry season water, there is a con- siderable potential for development. 6.30 Aside from agricultural development programs, of which the most notable is the introduction of high-yielding varieties, there has been a renewal of efforts over the past few years to upgrade and extend the existing water control infrastructure. Coastal embankments and salinity control structures on the canals have been repaired, some new control structures are now under construction, and a start has been made on the large backlog of canal dredging. At the same time, farmers in some areas have begun to use small low-lift pumps for irrigation. 6.31 A number of development proJects are under consideration. Studies have been made of two projects for irrigation and salinity control in the Go Cong and Kien Hoa provinces. Parts of the Tiep Nhut salinity control projects have been constructed and designs have been prepared for a large control structure desined to protect over 50,000 ha from salinity intrusion. In the deeply flooded upper Delta, the Caisan project - a scheme to provi(iA flood protection nnd irrigation of 60.000 ha -- has been identified, In varying degrees, however, all of these projects need to bh prepnred in more detanl bef^nre they nryild be nnqiderPd readnd for implenentation. 6.32 There are good possibilities for diversified cropping on the wPX 7~~~~~+; 1 _ 1 5~~~~~ 1 wTAn am 4-n_1+M_ n-+ XXrw s.1o-za hpn-9r;. .+ fetile alluvial Soils of the- vDlta, t 1w _rw IsA boVlr? VU.-X5 main canals in the upper and middle Delta where fresh water is available * J4 VtlIy..J. tUL J,.,r.J 4 al- o * T.g th4,s dIr Tao In on.. l r Dt 5 intyn+tlsio:QAL& is a constraint on dry season irrigation. However, if control structures are~~ uro de oprever.t sc"lUdby inbusion, W.= freshII waterU. retUa:.ed ;-. the canals has considerable value for irrigation of higher value crops nnr 4 ,A _ay ..5 k..y 1re .A nj A,- Pr., Ar n A,+ A }vsrsv }.,r. A nvlg- +v.v w andL va1S sov 9vor do&mestvlC wauerSU y JWAr LI 14 =1 " &dLG L"Q.j CULA" d..L.O' %J4. "J JA.'II±v~'J.A' d.'L JLL.kJJ9_LJ. 6.,3 A ~recer.t A dvlp.-. >ass be'Ien 4vhe -4-.roducto of- sorh s Z1. JJ v .± "V _A)L LU A.LI LOU tJ UJ A LJ.U. W.L..UL.'J J.L OS~'. LrDLA4. d.., dry-season crop in the floating rice zone, which has been successful -W.LIo'UU UrJ-ga nJ.oL; depletion o resiuuaal SOU.S IouistLW ±r preved by leaving the rice straw on the ground until the sorghum crop is harvested. 6.34 Long-range planning has also received attention. Two conceptual plan-ls havue been preparea; one by Development and nesources Corporation (D&R) in cooperation with a government planning group, and one outlined in the Indicative Basin Plan. Tne two proposals have much in common but differ in scope and timing. 6.35 The D&R report proposed a massive investment in water control works in the Vietnamese Delta over an area of 1.6 million ha. The physical works envisaged comprise a system of levees extending on both sides of the Mekong and Bassac stopping short of the Khrer border. These levees would be primarily for flood control down to Can Tho and would continue thereafter for the purpose of salinity control. Within the protected area existing canals wuould be used and, wrhere necessary, extended tc) provide a complete system of irrigation and drainage channels, with a series of pumps and control structures to regulate the flow of water. Navigation locks would be inccrporated at certain points to permit the movement of low draught boats. The estimated capital cost of the program was US$1.25 billion. The program was phased in four stages over a period of 20 years from 1971-1990 with the major works substantially complete by 1986. Increased production would result from lateral expansion, improved aaricultural practices, flood control and irrigation, leading to agricultural production of 5.44 million tons of paddy equivalent in 1980 and 11.73 million tons in 1990. The major component of this increase, about three-quarters, arises from dry-season irrigation on the 1.6 million ha. 6.36 Included as one of the malor orolects in the Indicative Basin Plan was a concnptual plan referred to as Delta Development. The major flood control and irrigation works were desianed to include the Delta in the Khmer Republic as well as Vietnam. The development was phased in two st.n'es tAm.-.d to oo1int-ifie rith th- imn1Pm.ntn.n+MAon nf t1he t.WO mninr upstream storage projects, Pa Mong and Stung Treng. Stage I (1983-1991) t,TO1l(ld oonn9it of' a ood embswdomer+ =1 ona + h l^etb^ of' the B_SS_G~a from Can Tho to Phnom Penh, followed by irrigation of 250.000 ha, 121,0 _nO-n t.z he na-r RPnnil ct ande 1 O/O-n IT =ientrnn_ qn1Jnln+,nr Adikes would also be constructed in the lcnier reaches of the Mekong and Bassac +o, combz4',.,+ sal;1nev~~ +,',,,t4r,sir. TT (1OO)20)O).O - A -^ -I 4-Et 44,,e flood embankments along the Bassac and Mekong Rivers from Kompong Chain 4to 4the -lower -14t44 of' 4the ooded -ea- -- VTie4-ns-- I r__gt-on .d - U'. U1lL ..LJ ~ J..LLI LU Vli_ .L.L_%JU'.LVt 1 .L dJ. _U 41 V .L'z1 AL~L1diL* L.LJ. .Lr'Lt.L'J11 cuiu.- drainage would be extended over a further 466,000 ha in the Khmer Repulolic e. 2,10-30,00 nr ,he ;r, Vi+tngl T..S te 0otd^5 +.c 'kn 'F I---A*. L~ ~~ .*J LO .~ ...tI,/L*A I* 4 S . "5 JW t 'L.. -LJ. .SJ-.? -J'.& completion of coastal embankments. The estimated expenditure during the plW perio 1-9180--000Y wv d e of 4e orde of- onb'lo TTS Aol I as. .1. LSAD. J'.5 ~'. S I'.. I.,.L.& JI~ V &L. US'. '0.n4OJ '.J. 'J.± .~ J.J.J1.L..L'.nSS U k A J..J&d. By making allowance for the effect of upstream storage projects, the scope o1 Vlse w01-H. wvul" UV _l'ess tiitu t1,, LXrz P.L-UpuiLOS O 4 .37 1Tustl^,eU1_ elabo -ato -f these plsns __Iqll rq -earuhme li .1' LWuLi-1-U. UUU.La4.'.LUIL UL! ViI±t:1t- pj.LLLI~ Wi.L.LJ x-i u.LL% d. morUL I±± detailed knowledge of Delta hydrology than presently exists. Also, irr-i>gaon on the scale proposed would onU y be possibOle following con- struction of a major upstream storage project. Another important factor in bhe form-u2abion oi long-range plans WALL be a clearer assessment Of the potential for more productive agriculture in the absence of large Lnvestments in water control. W." - ~ ~ A~ ~ VAA- AIIW-" ' -II UL%C'.J.JV '%A~IV,.A.iJLUICUIVQJ VJ.. UiJJ, jJJ Lf1IU.LqiJ. ±U.L- agricultural development in the Delta is the amount of water which can be AJ. divLe- ted La= th L-LJ- saLJl1 -u, Lu I Ieff,UC of s-LchI UIVisrsluns On salinity intrusion. A much more detailed kncaledge of the relationship bet-ween d-y-season flo-ws and salinity intrusion is needed for the planning of major developments. This need is fully recognized by the Government -4 TT:- -4___ __1- ___ - _ -_ _- _- __ *- _1_ - _ - - _- ._ - - _ _ . . Vo VieLtna who are UUbeg assiste in the training Co personnel ana tne procurement of equipment by the Mekong Secretariat and USAID, A program of hyudrologic observations in the Delta should have the highest priority. The results of such a program will be essential to determine the timing and magnitude of benefits from low-flow augmentation provided by upstream storage projectso VII. A REVIEW OF MAINSTE3 PROJECTS A. Introduction 7.01 The Indicative Basin Plan proposed the construction of six major projects in the following sequence: Sambor (1981), Nam Theun (1981), Pa Mong (1983), Stung Treng (1992), Ban Koum (1997), and High Luang Prabang (1999). Except for Nam Theun, a project on a Mekong tributary in Laos, the projects are all on the mainstem of the Mekong. The plan was conceived in accordance with the principle that power requirements of the four riparian countries for the period 1980-2000 would be met by exploiting the hvdro-electric potential of the Mekong Basin. 7.02 All of the mainstem projects would derive their primary bene- fits from power generation. but two of the proiects - Pa Mong and Stung Treng - because of their large reservoirs, would have other attributes in terms of Basin develornment. Pa Mong wrnl d open unp possibilities for irrigation in Northeast Thailand and conisiderably reduce flooding in the upper and middlP reaches of the 1,konge St ng Treng would offer poSSI- bilities for irl gation in the Khmer Republic, and eliminate flooding of large areas i n t:,e Deleta which ae now subject to irnudation every year. Also the projects would substantially increase dry season flows in the Yekong Deltna. n facts eitherof t.he projects alon.e would provide dry- season flows in excess of any foreseeable requirements for Delta irri- mqtionnr and - pi k-'o i.Jth propvr -r ation tbe large - servoirs would also offer opportunities for substantial fisheries development. 7.03 In their review of mainstem development, the Bank and its consultants concentrated on three of Fhe si-. ProJe -" Pa Mong, StunL Treng and Sambor. The first two obviously merit attention because they ^-e~~~~~ th r; rJcswt fii,l t-g o e-ven o'b t -- wride _ _ .'Y jJL W LU 0U.LJ.U.LUJtVU ZkUO.L-aV" tJ tVeL UUL L,IB WU seasonal variations in river flows. Also, they are not only the largest studied in considerably more detail than any other project on the mainstem. Work on Su+ng Treng has bee. conf-ed to mapp-ng und geoph--cal ve gations, and a desk study by the Mekong Secretariat. Further desk studies of thXe projec were made by the Baak's cons rultntsa The Sambor Project was selected for review because it has been the subject of a feasibility gade svtdy and it was assigned pr-iority in the Indicative Basin Plan. 7 ni. L. r t , n -_ n - __ n -t -'- '- - * I- - I -' 7I .4 The T1cL a Oa Drage, wichn had been investigated unaer the auspices of the Mekong Committee, was also reviewed. This is a scheme for a barrage across tne Tonle Sap designed to utilize the Great Lake in the Khmer Republic as a storage reservoir. - 52 - 7.05 The Ban Koum and High Luang Prabang Projects have a low priority for development nnd do not me-rit cronsiderntio^nr nt thi time.- FurthArmore, little information is available for these projects, As in the case of *m,h^"_or, the Ban Koeim reservoM ir cmThnll nndde lwnm..en.iil r riannvwd *^n prior construction of Pa Mong. The High Luang Prabang Project has less stora,, andd - wr porti {-n Pa Mong -.d requi-res r.c lse t-nn.s- mission lines0 Lack of data also precluded a review of the Nam Theun sDJ oC ' B. Project Evaluation Methodologw 7.06 As a means of assessing the relative economic merits of alter- na-tive modes of power development and to provide a comlpar-ison between mainstem projects the Bank's consultants used the "equalizing discount ratz' (EDR). This is the discount rate which equalizes the present value of costs (capital costs and operation, maintenance and replacement costs) of alternative power systems developments designed to meet an identical load growth, atltipurpose benefits of storage dams were considered as offsets to the c.st of hydro-po%er development, in the case of Pa hong and Stung Treng bnch project was evaluated as though it would be the first project constructed on the mainstem. The intention was to determine whether either project had so mn-rked an economic advantage that it could be a factor in deciding the seqaence of implementation (other factors would also have considerable weight, not least the more advanced state of investigations at Pa Miong). The earliest date at which it was considered feasible for the projects to become operational as a "first-in" project was taken as 1983 for Pa Mong and 1985 for Stung Treng, 7.07 In the case of Sambor, the project formulation would depend on the status of upstream development. With upstream storage a larger power-plant capacity is justified and the annual energy generation is increased. Three alternatives were therefore considered: (1) as an isolated project with an installed capacity of 1 ,500 IW, operational in 1983 (2) as a project in conjunction with Pa Mong with an installed capacity of 3,000 MW, operational in 1983 (3) as a project constructed after Stung Treng with an installed capacity of 4,500 NW, operational in 1991. 7.08 The comparative analyses of the three mainstem projects were conducted by Sir Alexander Gibb and Partners in association with Merz and McLellan. These analyses used similar alternative thermal-power developments and took into account irrigation and flood control benefits. Secondary benefits from improved navigation, fisheries, domestic water supply, etc.. could not be auantified with any degree of precision and they were therefore excluded from the analysis. 7.09 Studies of Pa Nong with special reference to its economics as a power project wtiere conducuuueteu by Ac-ces s as)L I ±1^ --- e L U ___.LI X__V 4 f/, I inu baslc; sCurce; 01 uaua VWr JUJ'UJf7,Lv u;V;:k C;v>ldvC as Wd;Is report of the United States Bureau of Reclamation on the Pa Mlong Project, which were based on 1969 price levels. Gibb anid Acres Jointly conducted a general review of the USBR cost estimates and up-dated them to mid-197() levels. Some changes were made in individual items, in pa ticular to reflect international rather than USA costs for generating equipment and transmission lines. The basic cost parameters were then used in preparing estimates for the Stung Treng and Sambor projects. Hydro Versus Thermal Power Comparisons 7.11 In the assessment of the relative economic merits of hydro- power development the conventional method of comparison with an alternatLve thermal power system development was used. The load forecasts given by the Mekong Secretariat in the Indicative Basin Plan were adopted as a basis for the analyses as it was the only forecast available for aIl four riparian countries.1/ Calculations were made for various prices of fuel oil ranging from 20 cents to 40 cents per million Btu.2/ 7.12 The teihnique employed can be illustrated by the procedures followed for Pa Mong. Two alternative plans were prepared for power systern developmient to meet prco;ected demands in Thailand and Laos. The system for the "Thermal Altern:tive" comprised existing and planned power plants in Thailand and Laos followed by a series of thermal plants added as required to meet projected demands. The system for the "Pa Mbng Alternative" differed only in that the Pa Mong units replaced an approxi- mately equivalent thermal capacity. Annual costs, both capital costs and operation, maintenance and replacement (0, M & R) costs, were computed for a 60-year period for each of the two alternatives. The "equalizing discount rate" is the rate at which the present values of the two cost streams become equal to each other. 7.13 The analysis was carried out for a 60-year period. It was assumed that, after the completion of Pa Mona. further capacity additions would be identical for both alternatives. Therefore, it was necessary to develoD installation schedules and load forecast only up to a point in time three years following the completion of Pa Mong. Beyond this point, 1/ Tin the ase of Pn Mong, stud±es were nnso made using several 'ifferen1t forecasts for Thailand. 2 Recent developments in the world oil markets have brought about S sQ+a-n+tal incrasQ in +.he r4c onf Phil oil nnd +the raong nf sensitivity tests is nmo being extended to 60 cents per million B+vu (e,rclus4w of t+ ~es and duties). the excess of 0. M & R costs for the Thermal Alternative over the Pa Mong Alternative were included in the cost stream of the Thermal Alternative for the remainder of the 60-vear period. Provision was made in both cost streams for replacement of thermal generating capacity every 33 years. The foreign exchange cornnonents of the Gost qtresnTnq were also Prmmite'ti to determine foreign exchange savings over the 60-year period of analysis. Irrigation and Flood Control Benefits 7.14 To estimate irrigation benefits attributable to the multipurpose priee-ts; a simnplifFied approach w..as adopted by, the consultar.ts. Thr,wee categories of irrigation were postulated: (i) High cost irrigation, either by direct gravity or sn,c,A4,n, 14l P+ ss o nnhnr.n P,7, .h:hb n, _n~n ,4rs *'M..%AJ.. t4J1 .la.. U J v *J WJ4flh o . iv4 W. L J Lf a Iv.L C Uc conveyance system would have to be developed at an esUt.i el aver-age cost ofL 0 per- hJaqt.L (Refe to discussion in paras. 5.20 to 5.23). (ii) Medium cost irrigation where an existing canal ""fras-tor UctLUre couULU Ube fUi'rItE' UdVeelo-pU at an average cost of US$400 per ha to permit widespread -UJ. .flUW-.l.L1 pumps. (iiL) Low cost irrigation where the existing infrastructure could be used without modification for low-lift pumping. Tne medium and low cost irrigation areas, each of about 500,000 ha in extent, lie in the Vietnamese Delta, and would be developed as a result of increasing dry season flow. in practice it was considered that all the low cost irrigation would have been developed from existing river flows and could not be attributed to mainstem development. Medium cost irrigation was assumed implemented at a rate of 20,000 ha per year. The hign cost irrigation areas would be located further upstream in the Khmer Republic and Northeast Thailand. It was assumed that 300,000 in each area would be developed at a rate of 10,000 ha per year mnitially rising to 20,000 ha per year after 10 years. Benefits were calculated as the net increase in value of agricultural production resulting from the irrigation works.1/ 7.15 The consultants used the estimates given in the USBR Pa Mong Report for flood benefits in the upper and middle reaches of the iekong. An independent technique for assessing flood benefits in the Delta was evolved which could be used for both Pa Nong and Stung Treng. It was assumed that the major source of flood benefits in the Delta would arise j/ Rice output was valued at $55 and $60 per metric ton of paddy at farm-gate depending on location., from enhanced use of land through changes in cultivation techniquea permitted by the improved hydraulic regime. The method used to estimate benefits was an elaboration of a technique developed initially by Development and Resources Corporation and subsequently by the Secretariat. The Delta was divided into four cultivation zones, high yielding varieties, single transplant, double transplant, and floating rice, according to the maximum flood depth which normally occurs in each zone. If thle flood depth is reduced by upstream storage it is assumed that the mode of cultivation will change with a consequent increase in yields. Changes in flood depths due to individual upstream projects were made by reference to the results of the Delta Model.1/ C. Pa Mong 7.16 The Pa Mong multipurpose project sited 20 kilometers upstream of Vientiane where the imekong forms the internationnI boundarv between Thailand and Laos has long been recognized as one of the major potential develonments on the mainstem of the Mekong. A feasibihity study w-yas started in 1963 by the United States Bureau of Reclamation and a Stage I report was completed in 1970. A Stage II report is nor nearing co_mpnletin. The Stage I report presented de.igns and supporting studies for the storage and power facilities, a d for a I3,000 ha irrigation development (11,000 ha in Laos, and 32,000 ha in Northeast Thailand). It is under- stood th-at the Stage II repor+t w-r1 prs4- pls f'o irriga+ - io ^f ab~i+ 650o,OO ha in Northeast Thailand.d Allowing four years for the pre- construction phase, including further sie s-tudies, detailed des±gn and tendering, followed by eight years to complete the main civil works, it is estitred that the sche,.me could beconme operational at the ear-liest by 1983. 7.17 The main structure at Pa Mong would be a concrete gravity dam 100 m high and 1 ,360 m long. This struct-ure wauld incorporate a 375 m spillway, capable of discharging 36,000 cms, flanked by a powerhouse on n JJAi '4 L1 t/k joU4J±(Leo) WU..L. uU U II4.VU TATJ¶. each sideo Each o.-L thAe luwovi po-ver-houses would contain 'fo-ar- 600-Malr generating units, to give a total installed capacity of 4,800 MW. Average annual energy generation would be 27,000 Gwn. ViruLally all of WhI out- put would be used in Thailand. Four 500-kv transmission lines with an intem.-lediate -Substation wo-uld connect the plant to the main load centers at Bangkok. Loads in Northeast Thailand would be served by 115-kv transm[ission lines from the plant and by 230-kv lines from the Cnaiyaphum substation, The output of Pa Mong would represent about 60% of Thailand's, power dexuand in the early 1990's - the earliest date by which all of the Pa Mong units could be installed. / A mathematical model developed for the Mekong Committee with UNDP assistance by the French firm SOGREAH for investigation of hydraulic problems in the Mebkong Delta, 7.18 To seal off two tributaries, the Nam: HIong and the IWam Lik, which pass through the reservoir area, a 70 m high and 2,000 m long earthfill dam would be constructed across the Nam iMong and a 90 m high arch dam across the Nam Lik. Together with over 20 km of dikes the three dams would create a reservoir of 98.3 milliards gross storage volume up to the normal maximum retention level at El 250 in and inundate an area of nearly 4,000 sq. km. The average annual flow of the river at the project site is about 145 milliards with a lowest recorded flow of 90 milliards, The proposed mode of operation would use about h2 milliards of storage, within the normal operating range of El 250 - El 236.5 m, for the loint nurnoses of nower, irrigation and flood control. 7.19 The total cost of the nroiect,. excluding irrigation works, is estimated by USBR at US$1 ,079 million (mid-1969 prices). A revised estimn+.e, up-dated to midl-1970. of 'TS.$1;133 million was derived by the Bank's consultants. This included one or two modifications to the proniect as well as an increase in the costs allowed for resettlement of the population displaced by the reservoir (see paragraph 7425 below). 7.20 Economic analyses based on the consultants cost estimates indicate the folIo w-g eq-riizngmv,y dicv.,ra+es Pa Mong - E2ualizin Discount Rates iTi-el Cost (cents per million Btu) Power only: 9.0 10.1 Power and direct irrigation: 9.3 10.4 Power, direct irrigation, and Delta irig"anti1.n.: 0.8 11.9 P~rwj0r drt~' nnrl Delta irn'igi~n.-d and flood control: 11.5 12.6 7.21 Power benefits are predominant since they accrue much earlier and more rapidly than- irrigation n benefits. Irri benefits in the Delta, as a result of low-flow augmentation, are more significant than benefits fromn diect irin Northeast Thailand. In fact, the results raise some doubts regarding the economic viability of direct irrigation if development costs approach $1,700,/ha as ndicated in the USBR Report (the consultants adopted a figure of $1.,000/ha). 7.22 The foregoing analyses were conducted by Sir Alexander Gibb ancl Partners in association with Merz and NcLe llan, and we.re desi;ged to provide a basis of comparison with Stung Treng and Samnbor. Studies by Acres International (Overseas) Ltd. were prlmarily devoted to testilg the sensitivity of the equalizing discount rate to changes in timing of the project. 7.23 The dam and reservoir costs, representing almost half of the total project cost would be expended before any power is produced. There- fore, the highest return to the project occurs when the generating units are installed as quickly as possible and the load growth is such that all of the output of the units can be absorbed in the system. Acres' studies showed that with the Moulton load forecast for Thailand, the equalizing discount rate increased, by about 1% if the commissioning date changes from 1983 to 1988, This is not in itself an argument for deferring this project, but it demonstrates that, in terms of power benefits, the equalizing discount rate is not adversely affected by a delay in imple- mentation. A further sensitivity analysis was conducted by Acres which showed that with a fuel price of 50 cents per million Btu, the equalizing discount rate for power alone increases by about 1.2'. 7.24 The dam structures have been designed with a normal retention level of the reservoir at El 250 m. At this level the power capacity of the project would be greatly enhanced compared with lower elevations, but it would result in the inundation of an area of over 4,000 sq. km containing a present population of about 280,000. By the mid-eighties, the total from normal population growth is likely to be approaching 450,000. While the project might be considered as technically feasible, it mnA be ouestioned whether an undertaking involving relocation on this scale, by far the largest ever attempted, is feasible on social grounds. Tt hin proved riiffMicilt to identify J Ind of Similnr awllitv to that farmed in the reservoir area for relocation of even a fraction of the (2. qdi !rl'a21 ±vI-l atw,^ >lthv-her'morn v t.he cosqts nl l rn. fonr mpett1 emRnt at about $40 per head (excluding administrative costs) appear to be very lnw. Tn .omparbhle projects in other parts of the world costs of up to $500 per head have been encountered.l/ 7.25 In view of the high costs associated with resettlement even if difficulties likely to be encountered in such a massive operation, it is reco.mm.en-.ded that fr ,her consideration sho' be iTn a s r.rth a lower reservoir level. 1/ Studies are in progress to prepare an up-dated evaluation of Pa Mbng Pro_ect which would consider among the various sensitivity tests the impact of alternative levels of resettlement costs on the equalizing discount rate. 7.26 In the course of their studies, USBR examined a number of alternatives over a range of reservoir levels. The lowest end of the range was a project with a normal retention level at El 230 m, but with the desi_gin fod pasi ng throigh the spillarynr the rpeqprvnir wtoii1d rY.ce to a maximum level of El 234 m. 7.27 The USBR scheme retained the Nam Lik and Nam Mong Dams. As q_-nd bel_ the resettleIr.t problem ^niI ,e hs + reduced if the reservoirs formed by these dams could be eliminated. Map studies indicate t+l-s,+' +Il a Ir ny"c.+1 t of Loei - Th;land, r.e of +h. l p u lation centers in the reservoir, would be unaffected provided the maximum pool cou'd be kept b4 I-,elow VI 20 - TJ--"'er esv at t -s I re' r el ativtey W.~ -W".%A -~ "~VV " .WW "~~_,P- ILO IAJLSv~ VVZJ. I V~.. O.U V.L...s. .L .5 -a. .S.. densely populated areas in the Vang Valley in Laos, wiould be inundated. n . 4-M - _ - ,A -5 1 A -[ - - A - 4 4- P- s 11 4- - _4- - to .4 - ;rsoI n,- - 41,,-nm-., SAL U UW iQ C;..I. L L O c jV V.L U L .L A U LW Jwi m f i JLV.JJ.3 U V- U CS.L U «A, Lat. -V the Pa Mong-Nam Lik saddle (approximately at El 220 m) and thereby elim-.iate the11 N%T- TLik Da,. an --eservoil-I Sm'- -ly f. ood ngA_ of- a I LJ4II.LL~d.IJCS IJ±' 'J dII U.LJ.L JJs.Jll SiAU. L_0:LV ..' OdJIL I I t.L.Ly, ±. L'LJUUJL16 %M.L a. .LdJ. number of villages and cultivated land in Udorn provinces in Thailand co-lud be preve-nLted by eliUmLna-ting the 11am iIong Dam,l and r-eservoi - the Nam Mong-Pa Mong saddle is in fact above El 230 me Therefore, it appears -3 _ _: _ __t _1 _ _____ ____ 1____1_____ _____ _ _ 1 _ __ t- _ ___ ___ desirable tu consider an alternative scheme Ln wnidn (aJ the Imaxumum flood level would not exceed El 230 m, (b) a dike at the Pa Mong-Nam Lik saddle would replace the Nam Lik Dam and reservoir, and (c) the Nam Iubng Dam and reservoir would be eliminated. According to the USBR study a project with a normal retention level of El 230 m would have an installed capacity of 3,200 j1W and annual energy generation of 17,700 GW4h. The effective storage between pool levels of El 230 m and El 216 m (excluding the Nam Lik and Nam MIong reservoirs) wrould be about 20 milliards - still a very large volume of storage; for example, almost twice the storage capacity of the Tarbela reservoir on the Indus. Flood benefits would be reduced as a result of the low storage capacity, but these are a small component of total benefits and the flood benefits in the Vientiane Plain may in any case be largely pre-empted by prior construction of levees. 7.28 In view of the above considerations, the Bank recommends that serious consideration be given to an alternative project formulation with a lower reservoir level in order to reduce the resettlement problem to more manageable proportions. Until such alternatives have been considered, an adequate resettlement program has been formulated and costed, timing and magnitude of agricultural benefits have been firmed up, and the project's ecological impact has been assessed, an adequate evaluation of Pa Mong Project is hardly possible. D. Stung Treng 7.29 Investigations of the Stung Treng Project are much less advanced. than those for Pa MIong or Sambor and have been confined to topographic mapping, geophysical surveys, and desk studies performed by the Mekong Secretariat. The Bankts consultants also conducted desk studies and arrived at a somewihat different formulation for the project than the Secretariat. 7.30 The site presently proposed for the Stung Treng dam lies on the YIekong River in Cambodia just downstream of the confluence with the Se San tributary. The scheme as formulated by the Bank's consultants would consist of a concrete gravity dam 70 m high, a 450 m spill-way section, a powerhouse with an installed capacity of 6,000 ivW, and earth embankments with a total length of 26 km. Although the area inundated by the reservoir would amount to nearly 9,000 sq, km the area of cultivable land submerged would probably be less than in the case of Pa Nbng, Pre- liminary studies by the Mekong Secretariat indicate a 1985 population in the reservoir area of about 270,000. The possibilities for resettlement might possibly be more favorable than in the case of Pa Mlong, since there are areas, particularly in the Ihmer Republic, which are sparsely populated. 7.31 The reservoir with a normal retention level at El 88 m would have a gross storage capacity of 110 milliards. The proposed mode of operation would utilize about 72 milliards for the purposes of power generation, flood control and irrigation, The total cost of the main struicture and transmission lines, but excluding any irrigation works, is estimated at US$1.87 billion. 7.32 The malor Dart of Droiect benefits would arise from electric power generation, which would amount to an average annual production of 35,000 C-lhh. Sited at a distance of 600 kn from Bangkok and 300 Icn from Saigon, the project could provide power to the major load centers in Thailwr.w Vietnam and 1mrbodia. Attenuation of the Mekong summer flmos by about 30"' would partially or totally relieve about 1 .75 million ha of culltivable 1 and in the KLm#er and Vietnarnese Delta areas from annual flooding, leading eventually to a more stable and profitable form of agricultur.al developmenr.6 A more immediate impact on agricultural production would arise from the augmentation of dry season flowJs, which would be more than sufficient to meet the ir-Jgation -rquiremPnts of the Mekong Delta, and would at the same tiine reduce the effects of saline n-H ben -F4 + ¶.rf~ A J."^1¶¶(de Jmy-~'v' ^ ri rira-in-m n r~ .L.LLW.i. wa * t.> bnefits would _l *f.prov.ed ..a..a-t,--- hi_ posil growth of a fishery industry in the reservoir. 7.33 An indicative economic evaluation of Stung Treng, assumed to be operational in * 985, v c^arried t on the sam-e basis as for P'a Mong; the results are as follows: Stung Treng - Equalizing Discount Rate Fuel Cost (cenL4s Pe4L , 'lion LJu) 30 LO Power only: 7.8 8.7 Power and direct irrigation: 8. Peower, di-ect irr_gation, and Delta irrigation: 9.6 1065 Power, direct and Delta irrigation, nnd flood control: 10.6 116. -60- 7.34 LiuJwalng Tor alL oe elits the equalizLi-g discount- rate ;for 40 cents fuel) is 11 .5 compared with 12.62o for Pa :iong. It is to be emphasized that eacn project has been considered for purposes of comparison as the first project on the mainstem. Irrigation benefits in the Delta, due to low-flow augmentation, could only be attributed to the first project constructed. Thus, as a second project, the equalizingr discount rate indicating cost offsets for agricultural and flood control benefits for either Pa Mong or Stung Treng would be about 12o less than indicated. 7.35 in recent discussions with the Pbkong Secretariat it has been learned that soils and topography in the areas that could be commanded from Stung Treng appear less favorable from the standpoint of irrigation development than so far assumed. If this is confirmed by further studies the equalizing discount rate for Stung Treng would be further reduced by about 0.7%. 7.36 Indicative estimates based on desk studies indicate that Stung Treng would cost some 50% more than Pa Mong while energy generation iwould be about 304 higher, Although, therefore, the equalizing discount rate based on power alone can be expected to fall below that of Pa M,long - 8% to 9, on the roi'gh estimates - its rating on total net benefits may prove comparable. Fo-eicn exchange savings would be somewhat higher than for Pa Mong. On the other hand, Stung Treng, lying completely outside the territory of either of the mann poaer consumers, poses in even more acute form than P'a Ilong the problem of site location in relation to national boundaries. iMoreover, whereas Thailand has negligible hydro- power potential to develop apart from Mekorg mainstem possibilities, Vietnam has perhaps 2,500 IS of potential, outside the Basin and on Basin tributaries, sufficiently attractive to warrant technical studies and which might suffice for powier needs into the tnineties. On the other hand, Stune Treng is the only mainstem project 'Thich could nrovide Vietnam with a substantial measure of flood protection for the delta. It would ao-ear that a cnreful weighing Qf these factors by the riparian countries concerned and a determination of policy is reqLuired before very extensive and e=pensive feasibility grade investigations of Stung Treng would be justified. E. Samrbor 7.37 The Samhovr Prnoiet on the I9Mkong near Krntie in the Khm.r Republic was given early priority for detailed investigation by the Mekenw flnmmi+t.ee tognethePr with Pn TAnna anA Tonle qnn- and a study was carried out by the Overseas Technical Cooperation Agency of Japan (nrrA) be+X.Teen 19n3 and 1969 PA.th ghi noab not as bit Pa Mr. or Stung Treng, Sambor is nevertheless a major scheme in terms of capital rulnF_r inA +l,ea m4mm n- +.Tigh : ; '- l vD vO;t t.Tv rPle t 4 - Q4 J+ Q _ 1_ - d _ _ - _.vI_ e n g- t_ ao_. 4 ., LD VJ WO of a low dam and spillway section of about 45 m maxiimum height, and just o.r~ ~~~~~~~~~C 1 ilrg_' coa;galo_crtHlloae ve LnteLV 7.38 About the same distance from Bangkok and 50 km closer to Saigon, Sambor would serve the same power market as Stung Treng, except where the project would be constructed prior to upstream storage, in which case Sambor was assumed to serve only Vietnam and the Ehmer Republic. To meet the Mekong Secretariat load forecast, OTCA proposed an Installed capacity of 875 NW for the project operating in isolation, increased to 2,100 IW when operated in conjunction irith Pa Mong. The f-bkong Sec.-etaxiat in its Indicative Basin Plan adopted an installed capacity of 3,000 NW when operating with Pa Niong and 3,250 MN when operating as part of an integrated river system wThich would also include Stung Treng. There is no unique answer to the choice of installed capacity as it is clearly dependent on the phasing of Sambor with other mainstem developments. It could be as high as 4,500 MN. For this reason, the Bank's consultants examined three alternatives with installed capacities of 1,500 PkiH, 3,000 MW and 4,500 IW to cover the various stages of mainstem (levelopment. Costs were estimated by the consultants on the same basis as for other projects. Annual energy production for these alternatives are given below: Sambor Project Alternatives Average Annual Cost (mid-l 970) aiergy (GWh) _US$ milion) (1) -Wfithout upstream storage Operational 1983 (1,500 144) 10,.00 527 (2) Wlith Pa Mong Operational 1983 (3,IOO 19;00Q fV9 (3) Wlith Stung Tren- Operational 1991 (4,;cQo ml 4) 25;O00 1;205 7,39 The economic evaluation carried out by OTCA showed a rather low enual i Zing discount rate for the nronect; nbhet S5% for an 87< KI installation and 7, for a 2,100 P&I capacity. For a 1,500 NW scheme the Bank's consultants deriv-d an equalizing discoumt rat+e of 9 a, and slightly higher values for the larger installations with upstream storage. This corresponds closely to t-h a-nalysis ofthe Mekong Secretariat. - 62 - 7.40 AAs formulated by OTCA, Sambor is essentially a power project. The proposed operating range for the reservoir would be between El 40 and El 38, which represents an active storage of 2 milliards. Flood storage space of 2.5 milliards would be pro-vided between El 40 and El 42, OTCA identified about 34,000 ha which could be irrigated directly from the Sambor project. The Bank's cornsultants adopted the basic project proposed by OTCA but, as mentioned above, they investigated alternative poer-plant capacities. The consultants also estimated benefits from direct irrigation and from low-flow augmentation in the Delta, and found that these benefits would have the effect of increasing the EDR to about 10%. 7.41 Sambor would be more attractive as a possible "first-in" project on the Mbkong if it provided a larger volume of storage to meet dry-season water needs in the Delta. A change in the proposed mode of reservoir ooeration would annear to meet this recnirenent. For examnle. if the reservoir -were operated between El 42 in the flood season and El 36 in the drv-season, the active storage avnilahle for low-flco augmentation would be about 6.2 milliards. This would be enough to increase the average f'lw at rnatie iTn Mmr,h a,nrl Armil f'rnon 2o00 r-GT to over 3,000 cms. This mode of operation would also have the effect of evev;ngin nit Tnn mt±hl. vanriatnH irwn in en-rr nori +3rnn_ T'v+.hae7 studies of thUe Svmbor project to investigate alternative modes of reservoir -e-ortno.-n to m+y-1m%efl m.~iiI 'tr,ip ,r.oe benefits dese p Finally it is to be noted that resettlement would be less of a problem than at Pa N=ong an"d Stun Trerg.g The " ese-A-4 rir wo ~ 'd nq.dat be1t 45000 and 5,000 ha of cultivated land which at present is occupied by a pop1 ratio of a-P d 15,000, F. Tonle Sap Barrage 7.42 The Great Lake in the KhmGer Republic, situated to the wiest of v***..e .4- 4a.Lv.eJ.0, Wi coV C1ecteU toJAIi41J itY aUJ .1t .'e Sap -LVV.Lq The natural direction of flow in the Tonle Sap River is from the Great T-1-s^ -1to- 4-h- Mekv-,Ag b_t dw-4-g 4he r-r . 4eso -'. wate-- leve - in the4 Mekong rises above that in the Lake causing the flow to reverse. The T A 1 __ - - - _ _Z .3: _ _ - - _- _ _. _ r, -. . _ n _t _ _-7 _JWICz. tLn al dus as d;> dt eUVAI4Uo d_ t raUage G;iG_ VU V-i- IlU.LU.Ug upJ vu UV 1i_1-arut_ of water. As the flood level of the Pekong begins to drop, the flow in Uh e m'"e Sap re-uj LtU tLsz nlolr,aJ. U.LL-e:.LUII anIU tll lfater svoreidu U1 L,Je Great Lake discharges into the main stem. 7.43 A report on designs and cost estimates for the Tonle Sap Barrage was prepared by the Government of India s Central water and Power Commission (CWPC) in 1964. The report proposed that a barrage, sited at the exit of the Great Lake into the Tonle Sap would be closed in the early part of the flood season, thus preventing flows from the Tonle Sap entering the Great Lake. A large volume of the Lake's storage capacity would thus be retained to absorb the later peak flood in the main river foliowing the 3e-opening of the gates. Thnis water would then be held back in the La'e and released slowly during the dry season to augment irrigation suI-lies and combat the problem of saiine intrusion in the Lower Mekong D32ta. Oether benefits envisaged include a revival of the fishing industr7r', Improved navigation, and limited hydro-electric pawer generation. 7.44 Opirions as to the merits of the project have been somewhat modilied since its original formulation. The Delta Model was used to study the effects of the barrage on flood levels in the Delta, and to derive criteria for operation. As a result of these studies, it was concluded that the flood attenuation potential of the project would be small and consequently the 1Mekong Secretariat rejected the scheme for early implementation in the development of the mainstem. Among the factors tending to limit the flood control effect of the barrage were (a) the need to keep the barrage open until mid-July to permit migration of fish into the Lake, (b) the large inflow to the Lake from surrounding tributaries, and (c) the limited conveyance capacity of the Tonle Sap River. 7.h5 Although the project would not provide any appreciable flood control, some benefits would arise from irrigation in the Delta and from the beneficial effect on fisheries in the Lake. The project as formu'- latei would have the effect of almost doubling the flow entering the Delta during the lowest months of the dry-season, The Lake is the chief center for the fishing industry in the lgmer Republic, but the present yield of about 30,000 tons is less than half the yields achieved 25 years agoo The French Fisheries Mission concluded that when the Lake reaches its lowest level there is a migration of fish from the Lake. The 'Iifssion concluded that prevention of this dry-season depletion in stocks (by holding the Lake one or two meters above its lowest level) could lead to an irmrovement in production. 7.46 There would be little justification for a project on the Tonle Sap if there was a strong possibility of Pa Mong coming into service in the 1980's. Nevertheless. in view of the uncertainties surrounding the implementation of massive developments on the mairnstem, and the possi- bility that there may be some urgencyr in uroviding dry-season water in the Ehmer and Vietnamese portions of the Delta, the concept of providing low-flow augmentation by controlling the Great Lake should not be rejected without further consideration. An alternative which merits further stadyt is a design which would nrovide control only over the out- flow from the Lake between surface levels of +4 and +2 meters. This is in contrast to t-he scheme- as present+ly formulated NihiCh is designed to control both outflow and inflow over a range of Lake levels between +10 and +1 meters. 7.47 The storage between +4 and +2 meters is about 7.5 milliards and if released during the two or three low-flow months the additional water supply would be sufficient for irrigating possibly 500,000 ha. Limiting the drawdown of the Lake to +2 meters could possibly have a beneficial effect on fisheries in the Lake. Ilowever, even in its modified form the project would still constitute an interference with one of the w.xorld's most complicated ecosystems and attention would have to be given to the ecological impact of civil works designed to change the regime of the Great Lake. G. General Considerations in Mainstem Development 7.48 The justification and timing of mainstem project development mast be viewed in the context of the increasing demand for power and irrigation wJithin the riparian countries, the need for flood control in specific areas of the basin and the advantages of improved irrigation along the river itself. However, the development of an international river involves considerably more technical, legal, political and administrative problems than that of a national river. Moreover, it requires the full commitment and the active participation of all the countries which are affected, (directly or indirectly, by such develop- ment, and in sor;i- cases, the chief beneficiary may not be the countrY in which the prcjects are located. Power Development 7.49 Powser needs will be an important determinant of the timing and seouence of mrinstem develonments. Althonph lnng-tPrm nronenti onnn mTnit be treated with caution, there will undoubtedly be rapidly increasing dem,nd for power in the nexct. 30 yevnrs Before. 1ggn the power demarn' ofn the riparian countries will have probably reached a sufficient level to 'hsorb at least one hy4ro-electric sczheome oun the' scale cor.templated in the mainstem projects. This demand can, of course, be met by conven- tionnl oil-fired or nnr-lenr instnll2Itinns buti-h in vie- of t.h lack of indigenous fuels such a mode of development involves a permanent commit- ment hy the ripLarian countries to USing energyc wthna a h.igh foreign exchange cost. However, some of the major hydropower projects lie outside of the coUntries with the largest de,wa Even courtr±es in areas &Aith a history of political stability have shown reluctance to depend on plants ou tside of their borders for a la-ge pa v4 th-ei p^wr the creation. of a regional power system will call for a high degree of Cooraration aw.d ut-I.-----c-A..Jder.ce .J±At' he 4es conceLd Irrigatienr. I 50I Lrigati =e,;.d as aJ. kdeerrun&.Ev) ~ --; A - of r 4nste., developrent are subject to an even greater degree of uncertainty than power demands. T.P.ere are hre areas of the, Basin.1 "i wh11ichU la.".10steml deIv"lo.,UII,Lt;1 wouid provide opportunities for large-scale irrigation - Northeast Thailand, 8i4h aWreLa Un . oth UoGeaLJ JjW1L .U.L ULU [I[L LteJpU.'vlic anIU th ivIeKong Delta. In Northeast Thailand, a first priority is to make effective use - 65 - of water stored in existing storage reservoirs; only when this has been accomplished will there- be a bnsis fnr judgmaPnts on th+ . nmis anrd timing of direct irrigation from Pa Mong. In the Khmer Republic, the areas whichi could'I be% ro.m.tndedar from q+-ngi Treng 'h^Y. ye tio+ n ben st-uied4r in any detail. In the Vietnam Delta there is considerable scope for dev.relopmr.en.t of lowl4f't ptt1,,p wri-i +41^-r-1'-' from "i- A vntn Hv%r irrigation diversions during the dry season would tend to worsen the snI+nty47.truio 4"bl- +Tq h. Tvs-r Dlta Thi-v the need Por a modest volume of upstream storage to increase dry-season flows in the Delt du:ga period ofP two t-o 4-U-e r.onths -M'I') _vo - an -,portnt-4 4.'.'d 'U...LUJ. a. jJ J. .L AJ LL UIW'. U' ulkU 00 £i1JLPI.. L.LLn IAJIIQ VO"L-Ial dLI' ALLI1JJJ.L. Ud.L.LU factor in mainstem development. A more detailed understanding than present" - exists of' --4--e- -'eni X - _ ' - f o . 'I_ _ _- ag-i-u'-a 4evlop,.e h absence of irrigation will also be needed to assess future irrigation needOsV. VutUe U.o tIhe VietUIaII elta, ULeUre haVre been viltuu 3.y I no attempts to adopt newi technologies in the production of rice, the Basinis principal agricultural products. ntensive effIorts di,rected to accumulating experience in the development of the water resources of the tributary basins and the delta and in promoting the development of rain- fed agriculture appear, therefore, as an essential prerequisite to decisions on irrigation from mainstem projects. 7.51 Ln contrast with many of the river basins of the world, the ibkong Basin of:'ers relatively few; technical obstacles to agreements on joint development for purposes of irrigation. At present, the use of dry-season flows of the Mekong by the upper riparians - the prime source of disputes in most other basti-is - is negligible. For many years to come pumping in the upper reaches will be small in comparison with the dry-season flow at Pa M-5ong which seldom falls below 1,000 cubic meters per second. Large-scale gravity diversions on the mainstem can only be achieved by elevating the water surface in the river - in other words by construction of storage reservoirs. In the case of Pa I4ong and Stung Treng the storage would be more than sufficient to meet potential diversion requirements, as well as to greatly increase dry-season flows in lowier reaches of the river. An added safeguard to the lower riparians is that Pa Mong and Stung Treng would be primarily operated as power projects and hence reservoir releases would be continuous. Flood Control 7.52 Considerable emphasis has been placed to date on the need to overcome the problem of flooding. In addition to specific reaches upstream, particularly the area around Vientiane, about five million ha is subject to annual flooding in the area of the Delta and around the Great Lake, The pattern of agricultural cultivation has evolved around this natural phenomenon, and varieties of rice are adapted to the particular flood conditions that prevail; however, flooding does result in a depression of vields in some areas. Also, flood dependent varieties possibly have less potential for yield increases than varieties cultivated under rainfed conditions. To some extent. however, the adverse effects - 66 - of floods can be circumvented by using short maturation varieties of rice in conjunction with low-lift pumping w^^hich will enable a higher- yielding crop to be harvested before the onset of the flood. Also, the introduction of sorghum as an "after-flood" crop in Vietnam has promise as a means of more productive land use without large investments in flood control. Thus, the flood problem as far as agriculture is concerned may now assume a lower priority than it has previously been given. 7.53 S-.irna Treng is the only project capable of provnidng a high degree of flood control in the lower reaches of the river and in the TDel+ta. hile flnod cn-+.ir is generallyr regarded as beneficial it wiTxll result in profound changes in the water regime, These changes could ni +.inII ir hc~ my nincr, - f' +.hcIia Tr n -+." . eollA- +nn Tr--.'i"+1 , .-nA .+h +_ -_ _ a. . -.v _ - , -EJ -J. . vv a. v f L'. careful advance planning. Agreements on the mode of operation of Stung Treng world A necessy+r to pr--ote+ +the ;-s4 oM-4-f_, --A. 41-t yJF~ . -' '' - _ _ 4 ~..'t. t) '.. V .L.U MSACWI L WA'. UWUt Khmer Republic, the riparians who wTould be affected by the project. Navigation 7.54 The need for improved navigation is generally accepted and ILad.LL UstU,m p iJ.LJJ.." w d e a Wene.L.LLcJ.J. effecUt, onLL spcii Ve.U reaches, However, no systematic attempt has yet been made to quantify Lravi CLUJ. 'LC.L benefi -L fina..clt Ute-,. '' thisII± - ± U. uone, they U ma Ust be regarded as an important but intangible benefit arising from river contr-ol, and any addituioal cost arising fromUx I±aVgatiol worLs wAll need to be properly justified. Environmental Considerations 7.55 A primary objective of resource develcpment should be to improv, on the natural environment - irrigation compensates for deficiencies in climate, flood control modifies river flows wrhich otherwise are damaging, the generat-ion of hydro-electric power and energy is a means of providing a more comfortable and productive environment. However, unless great care is exercised in project planning and management there is a risk of the beneficial effects of development being outweighed in whole, or in part, by adverse environmental consequences. This is particularly true in a tropical environment, and even more so when development involves impounding the waters of one of the world's largest rivers, which with its present regime has been an important determinant of the socio- cultural development of the riparian peoples. 7.56 The Mekong Committee is fully aware of the environmental and ecological risks of mainstem development and the need for analysis and evaluation. Studies so far conducted under the auspices of the Committee have served to indicate the dimensions of some of the problems that might be encountered; such as the possible spread of waterborne diseases and - 67 - parasites, the growth of algae and aquatic weeds, and the effects of reservoirs (both adverse and beneficial) on fisheries. However, much remains to be done before the adverse consequences of development can be predicted and solutions can be found so that the benefits of develop- ment can be realized with minimal adverse effects on both the human and non-human ecoloev. The Resettlement Problem 7.57 Targe-scale resettlement of popnulation from the proposed reservoirs is one of the most difficult problems to be faced and one thnt may have n fr-reaching effect on the formulation not only of mainstem projects, but also major reservoir developments on the tributari.es. Tn the case of Pa M>Tng. t1he maiitubde of the resettlement problem is sucl- that serious consideration should be given to an alternative formulation of the project, as suggested earlier in this chapter When flmtig'tion_ of the Stung Treng Project are resumed a first priority should be given to est;,ating resttlem,ent and rlocation requ44,eme.ats at diferent reservoir levels. Project Readiness 7.58 The Baakts review has confirmed the findings of the M4ekong CorTM.u iee t'a ruvpupose d velopm,ent of the i"ekong P.iver is tecF1nI- cally feasible and in the long-termi holds consid--able promise for regional ecoUnomIic development0 o Horever., numerois problemis attendant both to the assessment of project costs and benefits and to the joint development of an international river will have to be resolved before decisions can be reached on the timing and sequence of these major investments. A number of important fol-lo-.up actions in the further preparation of these projects have been idenrtified in the recommended Priority Program. Furthermore, it is hoped that other project-oriented basin and national planning activities identified in the Priority Program and in the IDbkong Committee's Work Program wi-l lead to a clearer perception of the costs and benefits of joint multipurpose development of the Mekcng River by the riparian governmentso VIII. A PRIORITY PROGRAM FOR BASIN DEVELOPMENT 8,01 Th.e Bank's recomm,.en,dat-ions for derelopment '+. nr,+.4tric to be undertaken in the near-term are presented in the following Priority Pogrm. This program specifies the ai e r to br4n to the stage of financing and implementation the more promising projects for --rrigate --d -- 4-1ed aKi tr4an_niates riortie for further investigation of mainstem projects. The recommended program of kJ.LWJa.lLig ar.U U"eVJ.ULoIPe1ntL act'.Lv±Lx5 is by r.o ,-,.eans ir.teunded tu Uv n11 activities to be carried out under the auspices of the Mekong Committee, btUu rather represents the Bank`s judgent- aS to activities wh-ch deser-e a priority claim on available finance and on the implementation of both ienong Secretariat ana riparian agencies. 8.02 iiMost of the promising opportunities for irrigation developento in the tributary basins and the Delta require further preparation before they could be considered ready for implementation. Tnis need for further preparation stems from the somewhat disappointing results of irrigation projects to date, and the now unanimous recognition that further capital investments sho"ld be preceded by careful and realistic planning. How- ever, wJ.th prompu and e tive action, there are projects in each of the national coni)o-vents of the Basin which could be brought to the implementation stage toward the end. of 1973. 8.03 The Priority Program 91so provides for further studies to provide a deeper understanding bhan presently exists of the present status of rainfed agriculture and potentials for future development. The Program includes the formulation of a central data bank, the application of space-borne remote sensing techniques in land resource surveys, a rainfed crop improvement program, and a survey of the high- yielding variety program in the Vietnam Delta. The Mekong Committee and its recently formed Agricultural Sub-Committee could have an important role in implementing these elements of the Program. The Agricultural Sub-Committee has been created to "promote cooperation between the Mekong Committee and the Ministries of Agriculture in the four Mekong countries, to harmonize agricultural aspects of Basin planning with national agri- cultural development plans and to formulate and coordinate research and experimental works in agriculture", 8.04 Recognizing the need for project preparation, the Mekong Committee in cooperation with UNDP and the Bank has formulated a Pioneer Projects Program which would concentrate on the identification and detailed formulation of projects for irrigated and rainfed agriculture. The pioneer projects would be prototvyes in which Dractical trials of the most promising approaches will lead, by successive modification, to to the selection of methods for application in full-scale development nrnicts+.q WimPrA nnnrnprin+,_ t.he fPnibiIi+.x studIies of the' e ill-scualp development projects will be carried out as an integral part of the pior.eer 1e Thple TheV1+.+~ .> or.I~eer _e,g . i9 fore an important feature of the Priority Program. 8.o5 Priorities for further studies of mainstem projects include ;- --ves4iatv. -4 f- Ia 1 'now Pa -lg investi-gations of Otern atve mo-,.ds .L1J. V J_r U .LVCJ.UJAJ. i.L ct LV .LAJIM ar'3 ±L4. L~9 VUQV..Lr AJ±L.LVAAQ .J. ClJLJ.L .&.VJ.iV %IA.J-3 of reservoir operation for Sambor, and a design study for a structure or4_ M--l-n __ r_- _-_nn:I-_'- J.1_ --- P__ 4r_ - AL _4e T_l__ UV1±= l JAI± t XLVI- V;IIJ±U J.JIG wit UUAi.L.LUW .L.-UUL iAii U.LtdLi .LJC1±1:. 8to6 The priucipal features OL the rriOrity rrogram ar-e brielly described below and summarized in Annex 1. A. Basinwide Studies 1* Pioneer Project Erogram: Identification and preparation of a program of pioneer agricultural projects. The program will include irrigation developments dependent upon dams and reservoirs under construction or already completed; irrigation developments dependent upon pumping schemes from the Mekong and its trioutaries; projects for irrigation, drainage and salinity control in the Mekong Delta; and improvements in rainfed crop production. All projects will give special attention to the requirements for comprehensive rural develo 'ment. The program of pre-investment studies is projected to require total expenditures of US$2.0 million. While the cost of implementation of such a program is still highly conjectural the figure of US$50.0 million has been used in dis- cussions with potential donors to indicate a rough order of magni- tude for total program costs. 2. Pa Mong Project: (a) Technical and economic studies of a project with maximum pool at about El 230 (Estimated Cost: us$0.5 million); (b) A review of environmental studies so far executed, identification of further studies and preparation of terms of reference for the execution of further studies (Estimated Cost: Us$0.o0 million); and (c) Execution of studies identified and formulated under (b) (Estimated Cost: USMo.- million). 3. Tonle Sap: Desien studies and cost estimntes for a stnm+intnr to control outflow from Great Lake between Lake levels of +4 and +2 meters above MSL. Prppnt proJect plans world inrolve ciril works costing US$140 million. It is expected that the proposed redesipn of the projee. %-l1 bring substant-ia savings in costs (Estimated Cost: US$0.2 million). - 70 - 4. Sambor Project: Stucdies to investigate alternative modes of v%nre;vs ,w t +.4rM +.n melvxm;4r 7I TMJ+.;i H,n-rt% hinmf4 +..A_ E! ~ rIl.s.,, e. (1 ' A , - ,s -? An,elr ,S4iiATrT 1vv4 yjei4rve *~~un g T p - z - r- - r- work of the Secretariat and the Bank's consultants leading to the ...assa..-4 n ,P 3-4-41-4 ~ nA 4 n.,s-s4'ns,.nn .Pn, .(%-.,4.1-nv - ~n^Vl preeparationL Vof dea;'ed..LI~ UUe1"^ ofL refec for .Vixe- y4wj investigations (Estimated Cost: US$001 million); (b) Site InveSg6aLviOns anu fea uJ.J.J..y study subject .vO ±.Li'±le~[=sro interest by riparians in project (Estimated Cost: US$12,0 million). 6. Delta Studies: Study in both Khmer and Vietnam portions of Delta to establish guidelines for future development,, and identify priority projects (study by Netherlands Team in progress, estimated cost of follow-up: US$0.6 million). 7. Central Data Bank: Establish a central data bank to store in computerized form all types of data pertaining to Basin development in conjunction with a comprehensive inventory and evaluation of the existing data base for basin planning (Estimated Cost: US$0.3 million). 80 Rainfed Crop_I2rov_ments: A basinwide program for research and field trials of techniques for improving agricultunJ. produc- tivity under rainfed conditions (Estimated Cost: US$300 million). 9. Agfuctural Data: A program for applying new techniques of remote sensing and data processing to the acquisition and analysis of data on land use, land capability, crops and crop production for the entire Basin. Arrangements have been made with NASA for coverage of the lIekong Basin by the Earth Resource Technology Satellite (ERTS) Program. Funds are reouired far round controls and data interpretations (Estimated Cost: US$0.h million). *B. Laos 1. Nam Ngum: (a) Operation studies to develop rules for reservoir operation following in-stmllt1rnn of spillway g+.es - tkni intn account flood reduction in Nam Ngum Valley and low-flow augmentation in the Delta: (f) TPnhnical and economi-c studires for instnlla:+.nn of additional power generating units (Estimated Cost: US$0.05 million). These studies mvy leand to fololt.n -nvestmen.t for +.the 4nsa+.niiM+.4," of spillway gates (US$0.6 million) and additional generating units 2.S FloMYntlli nns, V a Plain Review and summariza existing proposals with a view to arriving at final decision on di1,4ng, .dsA s-i, prt4e-4c4to (st'-.e fl-4L- TT:U$0el 'I iWn flJ.4 JSJ.f. ~i. ~ .L'.J.L i-J.J0 UJ4lkia~ Le U ii 1 . i LXUQs II I ILIL±ULLIo 3. Nam Ng Valley: Survey of potential for agricultural 3 vUopr-ent In the arxa -ewen t.; Tirt.e4sadth L~Vet8.L j iklu LUl Ijlit Lr J LJW _ UVV uJV V LV11U.J.C.L%- A J.C&AAAI CLI% Ull~ J.Vd.IL Ngum dam site (Estimated Cost: US$0.2 million). 4. Resource Surveys: Security situation permitting, reconnais- sance surveys Of' land usej soils, crops a,d crop production In areas which are potential sources of agricultural products for major population cen'-ers J- I-os (EstiMau-ted Cs uOs .I 11J.J.Lu'.o C. Northeast Thailand 1. Irrigation from existing reservoirs: Surveys OI the current status of construction of canal systems served by existing reservoirs and preparation of plans for their completion. Stage I would cover selected priority areas totalling about 40.,000 ha, and Stage II would cover about 100,000 ha of the remaining area. (Estimated Cost: US$0.6 million). Follow-up investments may total about US$35 million. 2. Flood protection study: There are large areas in the lower reaches of Nam Mun where annual flooding imposes a severe constraint on crop production. Studies are needed to establish the nature of the problem and to indicate possible remedies. (Estimated Cost: US$0e15 million). FollowSup investments may require outlays in the order of magnitude of US$5-0 million. 3. Developmentstudies on Nam Chi: Two areas on Nam Chi (Bantoom Bantiew and Sang Badang) are presently protected from flooding. The possibility of irrigation in these areas using releases from upstreaum reservoirs merits consideration. (Estimated Cost: US$0.2 million). A very first estimate of follow-up investments US$5eO million. he Rainfed Crop Improvement: Identify possibilities for production increases and quality improvement for dry-foot crops such as kenaf, cassava, cotton, oilseeds. and corn (Estimated Cost: US$0.2 millicln). D. Khmer Renublic 1. Prek Thnot Proiect: Completion of irrigation system designed for Stage I (5,000 ha) to be served from storage and diversion works presently under construction. Planning studies for ultimate expansion of service area to 70,000 ha. (Estimate subject to further review; a notional cost of MOS1 .0 mav be anpronriate). These works are ongoing, but additional funds may be required. 2. Stung Battambang: Several planning reports have been prepared for a TmAntApipose project on Stung Battambang.. FrthAv tA hJninl and economic studies are needed, especially consideration of staged develoYm%wm1v% (V.,+ ved+aA rt:%v2+. TJqt.) 4 1m411,i J V.- q-;.- =+aiie_s propose a project costing US$20.0 million. - 72 - 3. Stung Chinit: Review feasibility report on this project which has recently been completed by OTCA (Estimated Cost: US$0.1 million). The recently completed feasibility study pertains to a project costing US$26.0 million. 4. Riverbank Farms: Review possibilities for further development of diversified agriculture on levee soils along Mekong (Estimated Cost: US$0,2 million). 5. Fisheries: Identifv measures required to arrest the decline in yields of the Great Lake (Estimated Cost: US$0.3 million). E. Vietnam Delta 1. Project Planning: Project identification and formulation for the foIJ.owi^ng areas: (a) Go Cong (50,000 hectares), Kien Hoa (100,o00 hectares); Tiep Nhut (50,000 hectares) - primarily salinity control and 4 xyw e,-,+A tmX (b Cas...,, (60,000 he^ars) ^Y A lrm" (1000 nnn hecare+ s - primarily flood protection, irrigation and drainage. To the ete r.4 v. pior.eer projects are be;n.g for. .+ated ;n nachl, o these projec'v areas, feasibility studies of the larger UdV%el.pirents may lue c L-xieud out as Wi .kV1-dL P -V oJ.f pioneer project implementation. However, to retain flexibility in proJect pr-eparation, adUUdJ2ILULtoL .LULiUU fL.Lr YrIvet i,,J=LIU studies will be required. (Estimated Cost: US$1.0 million). 2. Low-lift Pumping: Survey of extent of low-lift pumping in the Delta, crops grown and impact on prOductiun, pumping practices and equipment, and forecasts of future growth (Estimated Cost: US$0JoL4 ViLL.L.LJ.VLJ . nip.Lhgfl L'ieldinUVariet,es (niv,r ProMuarfi* rreparation oI a repo.r E describing history, present status and future prospects for the cultivation of hign yielding rice varieties (Estimated Cost: US$0.1 million). 4. Hydrologic Data Collection: Implement a program designed to provide an understanding of the occurrence and effects of salinity intrusion and the possible consequences of increasing diversion during periods of low flow (Estimated Cost: US$05 mi.llion). 5. Inventory of Water Control Infrastructure: A survey to obtain up-to-date information on the present ccndition and performance of canals, canal structures, and salinity control works (Estimated Cost: UJS$0.3 million). - 73 - 8.07 The above-listed studies and investigations are designed to promote investments in the period immediately ahead and to lead logi- cally into a longer term basin development program. The Priority Program would recuire a eommitment of about US$12 million to meet the highest priority needs for expeditious preparation of land and water development projects in the 1nsin. Within this totnl, provision has Also been made to fund the most urgent follow-up to past and ongoing studies of the most promising ma±nstem projerts. Provided thnt these prP-_investmPnt fnnds are committed during the course of 1972 and 1973, and assuming further tha+t se,.4titr crj,,dit+ons *1 1j ie nece 'rw P4&1A vork, the tw-tir Program can be expected to result in the preparation of a "pipeline" of pr,4^4oTriypoet reir, ,- 4-e - cv--se ofP t.>e perod rn 1097 ton , - ' ~- "J I' -, .LWUJJ..L i , ' .L Y.JX- W..JL QU WJ. L~ VA - 4.'....4A . ' ." /[I - - 1978, commitments of US$250 million to cover total project costs. Given +heprsnts+t _of pre=ves--,,ent4 s4-,,is 4this est 4,-4e is of - esiP highly conjectural, and the uncertainties about future security conditions, anLu poL.Lcies ar1 p.ior Jes ol de IJI4pE-l guyI-(l,tsiLi Lua-lltu1- redLuLe this projection to a mere order-of-magnitude guess. Finally, the Basin developmuent program includes mainstem projects which would require unusually large, indivisible investments and even the best prepared of the mainstem projects are sti-l undergoing close scrutiny, the outeonw of which cannot be pre-judged. The above projections have, therefore, been confined to tributary projects and other land and water development activities on the basis of reasonable assumptions about project pre- paration requirements and likely improvements in the implementation capacity of the riparian governments. With these qualifications, the estimate of an investment program of $250 million is advanced as a first indication of the likely short-term outcome of the proposed $12 million program of pro-investment studies. ANNEX 1 LOWER MEKONG BASIN nnATflrq.)IV DDCfXPflA U Estimated Estimated Estimated Estimated Cost Cost of Cost Cost of Description of Pre- Likely Description of Pre- Likely Investment Follow-up Investment Follow-up Studies Investment Studies Investment ($ million) ($ million) ($ million) (S million) A. BASINWIDE STUDIES C. NORTHEAST THAILAND 1. Pioneer Project Program jI 50.0 1. Irrigation from Ebcisting Reservoirs 2. Pa Hong Project (a) Stage I (40,000 ha) C.MD (a) Study of Low Pa H4ong 0.50 (b) Stage II 0.!40 ( b) Review & Formulation of Ecological Studies 0.05 2. Nam Man Flood Protection 0.20 (c) Ecological Studies 0.50 3. NQVII ChiL Developr,LenIt 0,'0 3. Tonle Sap Project 0.20 4. Rainfed Crop Improvement 0.20 .4~ ACJLUo IoJJe- 0.20U*C Sub-Total 1.20 45.0 5. Stung Treng Project Desk Study 0.10&/ - D . 1HIwER REPSUBLIC 6. Delta Study (follow-up) 0.60 1- Prek Thnot Proi;c.t - 1. t entral Data Bank 0.30 Phase II 1 .00 8. .-ainfed Crop Improvement 2. Batt- bang oject 0.4 0 Hesearch and Field Flcperiments 3.00 9. lmDrovement of Agricultural 3. Stung Chinit Project 0.10 Data Base 0.4°0__ 4. Riverbank Farms 0.20 Sub-Total q8 .o 0 - - =_35. Fisheries Studies 0.30 B. LAOS Sub-Total 2.00 50.0 1. Nam Ngum Project (Re: Spillway Gates and Phase II) 0.05 E. VIETNAM DELTA 2. Flood Protection for 1. Project Planning 1.00 Vientiane Plain 0.10 2. Review of Low-lift Pump 3. Reconnaissance Studies for Development 0.)J0 Nam ND m vallev 0.20 3. Review of High Yielding 4. Resource Surveys 0.30 Variety Program 0.l0 Sub-Total 0.65 25.0-2! 4. Hydrologic Data Collection 0.50 5. Lnventory of Water Control Infrastructure 0.30 Sub-Total 2.30 8o.o0- T 0 T A L 12.00 250.0 1/ Estimated cost of US$ 2.0 million already funded. 2/ Site investigations and feasibility study estimated at US$ 12 million should be deferred pending review of desk studies by riparian Governments. Ti rovy, ih~ ro. of' ri.a _ f ow-g 4--.- c o.1 i gv'l Spllwa Dates; and Flood and Bank Protection Works for Vientiane. I/ To cover the cost of the following possible investments: two major tributary projects: and one program of' minor irrigation works. 5/ To cover the cost of the following possible investments: one major salinity control and irrigation project. including rehabilitation o0 existing sea delenses; one f-lood protection, irrigation and drainage project including rehabilitation of existing water control works; and one program for low-lift pump development. ANNEX 2 LAND AREA AND POPTILATTOM r,ographicnl tyea Estimated 1970 Population Area - (km2) Total Densit; Rural Urban (000) (per km-) (OOO) (OOO) Mhmer Republic 181 ,035 6,938 38.3 6,154 784 Laos 236,80o 2,962 12.5 2,634 328 Thailand 5143000 35,814 69e7 30,614 5,200 Rep. of Vietnam 173,263 18,128 104.6 149525 3,603 Totals 1,10,5098 63,842 57.8 53.,927 9v,915 Lower Mekong Basin: Khmer Republic 163v797 6,459 39.4 5,719 740 Laos 220,500 2,769 12.6 2,448 321 Northeast Thailand 170,226 12,608 74.1 12,148 460 Northern Thailand 18,803 1,139 60.6 1,098 41 Delta Provinces (Vietnam) 37.911 6.71L 177.1 6.100 6114 Central Highlands (Vietnam) 34,118 646 18.9 585 61 Total (3asin) 645,355 30,335 47.0 28,098 2,237 Percentage in Basi. 58.4 47.5 81.3 52.1 22.6 ANNEX 3 Indicative Basin Plan Short-Ranze Plan (1j70-1980) Irrigated Installed Estimated Area Caracity Cost (hectares) (MW) ($ million) UI.L flRepUblic. . Prek Thnot. P*ninntl/ 3$ ,00 1 8 $1 4 Battambang Project 68,000 37 91 Tln--mnl Pmuyo-" <+nvH tw Ther.m.t1 PXYr S+-ation -45 8 Transmission Lines - 5 Sub-total 103,000 100 158 Laos: -os 1/ Nam Ngum Project 35,000 130 80 Nam Dong and Se Done2/ - 3 4 Sub-total 35,oO 133 84 Northern Thailand: Completion of seven multi- purpose projects 1/ 232,000 36 169 Nam Phrom Hydroelectric Project 1/ - 60 22 Pak Mmn Hydroelectric Project 100 32 Sub-total 2 3 2,0 19622 Vietnam: Dannim Hiydro (Rehabilitate and Extend) 332 68 uput;r- Lie<. oorXL [aU.Cjet r_U pW ,7C Upper Se Prok ProAect 24,500 26 35 A!oder" l$ tW 0XmnF the I)ZLt, 40,000 - 40 Tnermal Power Stations - ouu 81 Transmission Lines - - 14 Sub-total 86,200 1,218 330 Basin SunM2: 1/ Under construction 2/ Completed 1971 ANN7EX 3 Indicative Basin Plan Projects in the Long-Range Plan (-180U-2uUU) Installed Annual Active Estimated Cost Project2/ Capacity Energy Storage (}Xw) (GWh) (billion m;-') ($ million) Naim Theun (1981) 2,500 8,000 6 243 Sambor (1981) 3,250 22,000 2 584 Pa Mong (1983) 4,800 24,000 42 844 Stung Treng (1992) 7,200 35,000 46 1 ,440 Ban Koum (1997) 3,300 20,000 - 637 High Luang Prabeng (1999) 2,-750 i5,000 10 412 Delta Development (1983)1/ - - - _ 0^ Of .4 -I -- -1 ZqZ /-3.$ 00 124,G00JU 1UU 4 1/ A plan for flood protection, irrigation, and salinity control in the Khmer and Vietnam parts of the Delta,. 2/ Costs sho(m are for dams and Dower Dlants onlv, the caDital costs of the Long-Range Plan as estimated in the Indicative Basin Plan Report are: US$ million Dams and power plants 4,160 PrWt-r transrniqqionnfclte 5 Direct Irrigation 1,274 Tiol fh nnlpo nrrpment 1,05 7 -),)0 ANNEX 4 LOWER MEKONG RIVER BASIN 0-^ ir-MA Ar'I% % IIhk1%3 IL I -rr%mi~ e-rA r%i.i e/%nTrRA SCHEMATiC SHO'vv;ING MmA;NT;U,AYSSE .r.III II.., I1IVVIINIL IVIMI N 1 K DU IAMI T -) I Z I LJV1 RIGHT BANK MEKONG RIVER LEFT BANK BORDER REACH ENTRY POINT-(LAOS/CHINA/BURMA BORDER)*- - - 234 K-.m_ CHIANG SAEN _ - (THAILAND) MAY KOK (THAILAND) I -.: NAM NGAOU (LAOS) ...... . (. AN, " BAN HOUEI SAI (LAOS) 1,:,, : --.-- ::.:- NAM THA (LAOS) E | I 'j " - - - --NAM BENG (LAOS) NAM NGEUN (LAOS) . ' -t-4PAK BENG (LAOS) |' -' - ;'F CNA: --NAM OU (LAOS) NAM SUONG (LAOS) 3! ,WLUANG PRABANG (LAO5) | ,..- . ::: .:NAM KHAN (LAOS) :,: , ..'', =:-:=::AM DONG (LAOS) SAYABOURY (LAOS) E NAM MET (LAOS) :::---: -* NAM HEUNG (LAOS): MAY NAM LOEI (THAILAND):..- CHIANG KHAN (THAILAND)J_ NAM MONG (THAILAND) 47 6 VIENTIANE (LAOS) - _ . _NAM NOLRM (LAOS) I .NAM NHIEP (LAOS) -________ NAM SANE (LAOS) NAM SONG KHRAM (THAILAND)-4 - - . . NAM CA DINH (NAM THEUN)-LAOS NAN O ' ,.,.,.,,,, . -NAM HIN BOUN (LAOS) 24 .... I-.--.rHAKHEK (LAOS) - NAM PYUNG (TTNAILA'r; i 1 =S ! SEANG FAI (IAOS) HIUAI BANG SAI (THAILANI: MUKDAr1I kirmA) ' SAVANNAKHET (LAOS) - NAM CHI ',,-,L-',CI,, .--.I I NAM MUN (THAIL AND)1,2 ||.6-SE BANG HIENG (LAOS) ir,.. .-- [.Jh- t | .- .i [ t | TO SCALE J II~~~~~~~ -NLt -i STUNG SANC.t_, - ...............i: L:I' . . . ;rnt-i _S ll (BATEAMBAN. - , . STUNG MOtN: Ai -R -4t STUNG DALINTRI STUNG PU: i J / .' -, r-NEAK LUONG (KHMER) PREI, i,-l .- r : F78ASSAC/ CHAUDOC UN. ' . SOUTH CHINA SEA - [ORD - 5744(R) 0 T. co g Ld LLi > 0 Lu LJ 7) A o, I E "Vo 00 tA Jr, ZS, T.O. 5-P 2 E 5 di ,0- IV > AOI co IN _MAP 2 \ loo- ~~~ ~ ~ ~~~~~~~~~~104- rs,k. t-3 ~~~~C H I N A s ,~~~~~~~~~~~~~ BASIN ) . i ' 1 _B\ Uf R M/g; A' Lae nd Reefo f 4 <,t '~~~~~~~~~~~~~~~~~~~~~~~~0-or k f t X ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~in // Pof o > t % $' ( u ~ ~~~~~~~~ < tOavonnskhel)' , _Jg HueA <~~~Eleolir i mee, *~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~h JBNG 'h, 1' .. .... . . ^' . 1 t t? $ \ s / e z 0 i) { ) Xy o%StungTreng2~~~~~~~~~~ - ~~^ n - ! 4ph 0 P 2 10 A \ J N g 1 wv em u z w~~~~,1-X r V o g A r Can a 9 Eno Co Chaiyaphurn 1-~~ ~~~~~~~~~~~~~~~~~~~~~~~~~~~IR -3 i49 FEBRUARY 1972~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~r [ \ 100~lo 104- "r; %AOff- t-, ~~~~C H I N A s | ) i '. aiA\ < t 9* >A0eservoirs and lokes i w %/r:~~~~~ rdouel Sr i AS / ~~ ~ ~~ ~~ ~~~~~~~~~~~~~~~~~~ porun to.ns0 0X: t~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~Itmtoa bOnc es|>\, T > O 2010 10 20 .ogtoGo9¢ )20 I-ZhongS A< b i 0 S0 100 IS,0 200 250 300 ff jf 20 Souzh Chno Se a~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~....... L s . . . ::. . 104 t f _ IOrJ- __ _ _ |~~~~~~~~Til b FElUR Y97 R-J40 T H A I L A N D 0'/¢ 6 r- t I , e X ( rk ~~~~~~~~~~~L A 055 cS I1 J -:-w! lm V > 1S-4 - ! oE~~~~~~~~~~~13-19,i I-K Wj AA t!F ,, E f Rt E P U B L I C 1 < ., ., .... i5 C........................................................................................................ A_._A -*2-> bi ff <\ \ * t ~~~t Pl.W0 s , K>Xompon @ 4 /t C A-- ''- W~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~0 1 WL.: fl % }Syt- jl*v ETN M Z hoi S a n a H5 4>_S t .r ~~~~~~~~~n .'C hn - | > to Fa-r4~~~~~~~~~~~~~~~~~~~6 A- * - <.hu - -t* s |TLowland Flo inothMengBai ..j ;,--,< ; | e | ' --. ... - ' 11.,,2-H !~~~~~~~~~~~~~~~~~~~~~~~~~~~~~1 sLinds of the [ower Melton~~~~~~~~~~~~~k.3 g B'r . - c2R@servoirs cmcl loLes q I t W > H~~~~~~~~~~~~~~~~~V. F *@v*@6BLimlloffloodedorso I 1 ! ,,7S<;l.0 s u Rice culilvolion W ~~~~~~~~~~~~~ <2 s 7iM. alr flood ricrs o 20 40 60 ao loo { . / /~~~~~~~~r RI LO E MEON BA I ror g J-;1 t;OEER ¢ / /SOUt1- Ch Types ot lieLiiaion inpl th 20 40o 60 C. F Q imporront rowns Y!LES c <~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~C Lowla end lodlaion bonof the Meon Basin ~~AlLimits of the Loe Meog6-inJ1 FE31UARY 19Z2 13RDvers it