Thailand - Phasom Dam Project

RETURN TC| REPORTS DESK WITHIN CIRCULATING COPY RESTRICTED ONE WEE BE R RND TO ARCHIVE DMIV Report No. TO-563a This report was prepared for use within the Bank and its affiliated organizations. They do not accept responsibility for its accuracy or completeness. The report may not be published nor may it be quoted as representing their views. INTERNATIONAL BANK FOR RECONSTRUCTION AND DEVELOPMENT INTERNATIONAL DEVELOPMENT ASSOCIATION PHASOM DAM PROJECT THAILAND March 23, 1967 Projects Department  CURRENCY EQUIVALENTS US $1. 00 = 20. 80 Bahts (1f) ffi 1 = US $0. 0481 1^ 1, 000, 000 = US $48, 077 AREA EQUIVALENTS - METRIC SYSTEM 1 Hectare (ha. ) = 2.47 acres 1 Hectare = 6.25 rai  THAIIAID PHASOM DAII PROJECT TABLE OF CONTENTS Page No. SUtiIARY .................ii INTRODUCTION. . . . . . . . . . . . . . . . . . . . . o . 1 BACKGROUND. . . . . . . . . . . . . . . . . . . . . . . . . 1 THE PROJECT AREA. . . . . . . . . . . . . . . . . . . * . . 3 General, . . 3 Present Status of Cultivation. . . . . . . . . . . . . Land Tenure. . . . . . . . . . ..... . 5 Transportation . . . . . . . . . . . . . . . . . . . . 5 Agricultural Production.o. .. . .a . . . . . .a . . . . 6 THE PROJECT * * * * * * * * * * * * * * a * *. a * * . * .a 6 Proposed Works .... a * a e.g...... so .... a...... .... 6 Status of Engineering. . . . . . . . . . . . . . . . . 8 Construction Cost Estimates. .. . . .. . .. . . . . 9 Construction Equipment and Supplies. . . . . o . . . . 9 Financing. . . . . . . . . . . . . . . . . . . . . . . 9 WIATER SUPPLY A1N1D REQUIREIENTS . . . . . . . . . . . .. 10 AGRICULTURAL DEVELOPIENT. . . . . . .. .. . . . . . . . 11 ORGANIZATIONAND'ANAGENET .. ... ... .. . ..... .. o o . 13 Construction .o. . . . * * . . . . . . . . . . . . . . 13 Studies and Reports. . . . . . . . . . . . . .a. .*. . 14 BENEFITS AND JUSTIFICATION. . . . . . . . . . . . . . . . . 1 CONCLUSIONS AND RECO1I0ENDATIONS . . . . . . . . . . . . . . 17 This report was prepared by Messrs. Bartsch, Sicely and Golan, and is based on findings of several missions which visited Thailand in 1965 and 1966.  ANNEES 1. Rice Taxes and Export Price of Rice 2. Proposed Construction Schedule 3. Description of Works 4. Estimate of Costs 5. Equipment and Supplies for Construction 6. Estimated Production Costs for Rice 7. Possible Alternative Patterns of Agricultural Develop- ment Utilizing Water from Bhumiphol and Phasom Reser-voirs 8. Rate of Agricultural Development and Net Returns MAPS Phasom Dam Project  THAILAMD PHASOM DAM PROJECT SUMMARY i. The Government of Thailand has requested a Bark loan to assist in financing the construction of the Phasom Dam on the Nan River in northern Thailand. The dam is located approximately 60 kilometers upstream of Uttaradit where the river leaves the mountains. ii. The proposed project is the fourth phase in the develop- ment of the Central Plain of Thailand, having been preceded by the construction of the Chainat Dam with a system of main canals, the Bhumiphol Dam and the ditches and dikes project, all of which pro- vide for the improvement of the agriculture and irrigation facilities of the Central Plain, and all of which have been assisted by loans from the Bank. The project would permit the storage of the monsoon flood flows of the Nan River, which could ultimately be used during the dry season for the irrigation of approxi-mately 380,000 hectares of land for the production of a second crop of agricultural pro- ducts where in general only one crop is now being grown annually, and a dependable irrigation supply for 100,000 hectares of wet season cropping in the Nan River Valley. si;. The estimated expenditure necessary to construct the Phasom Dam, including costs of construction, purchase of equipment and consulting services, would be approximately 0 1,582 million (US$ 76.2 million), of which US$ 30.5 million would be in foreign exchange and includes interest during construction. The proposed Bank loan of US$ 10 million would cover approximately 38 percent of the foreign exchange cost, except interest during construction, and woald be about 13 percent of the total estimated cost. Design and supervision of construction of the project would be the responsibility of con- sultants employed by the Royal Irrigation Department (RID) of the Ministry of National Development. The main dam of the project would be constructed by contractors selected through international competitive bidding procedures. Most other works,, such as the saddle dams, roads and camp construction, would be performed by force account by the RID and with the assistance and advice of the consultants. In addition to the construction work, studies would be conducted, leading to two reports, one for an irrigation project in the Nan River Valley, to be completed by the end of .1969, and another for the intensification of second cropping in the Chao Phya area, to be completed by the end of September 1969. iv. Preliminary studies of a proposed power installation at the Phasom Dam show that the addition of power facilities would improve the economic returns from the project. Further studies would be made to determine the best timing for installation and the optimum capacity of power generating facilities. The studies would be completed by the end of 1967.  - ii - V. The RID would be responsible for the operation and maintern- ance of the project. vi. The benefits from the project would be attained primarily through second cropping, during the dry season, of lands which lie downstream from the dam site. Justification of the project there- fore depends upon the rate at which farmers can be induced to change their normal pattern of single crop cultivation. For optimum development of second cropping, the Government of Thailand would have to greatly expand its program of agricultural extension services, fertilizers, improved seeds, pesticides, credit and marketing. vii. At full development, a measure of the economic benefits of the project in the Chao Phya area is an increase in the annual net value of production at farm prices of US$ 11.6 million. Tax collections in the form of Rice Premium and Export Taxes on all rice produced would amount to US$ 13.0 million, thus the annual incremen- tal net value would be about US$ 24.6 million. At this level, the average annual net return from second crop irrigation of rice in the Chao Phya area alone would range between 6 and 10 percent, depending on the assumed rate of second crop development. When the benefits from a possible future project in the Nan River Valley area are added, tl-e economic returns increase considerably to between 11 and 14 percent. Even higher returns would result if second crops of higher value other than rice are grown and if the power benefits are taken into consideration. viii. The shortage of data on land resources, the problems of intensifying agricultural production and the necessity to make a num- ber of broad judgments as to costs, crop yields, market potentials and rates of agricultural development have made the project dif- ficult to appraise. However, the past satisfactory performance of RID on similar projects and the traditional orientation of the Thai farmer to irrigated agriculture are favorable elements. Furthermore, on minimum (and in fact unrealistic) assumptions, the economic return would not be less than 6 percent, even without taking into account the added benefits which could be expected to accrue from the irrigation of the Nan River Valley, the growing of more valuable crops than rice, power generation, flood control and salinity control. All have been factors in reaching a conclusion that the project is one which could be expected to be successful and helpful to the economny of Thailand. ix. The project is suitable for a Bank loan of US$ 10 million. The borrower would be the Kingdom of Thailand and an appropriate term wauld be 20 years, including a grace period of 6 years.  THAILAND PHASOM DAM PROJECT 1. INTRODUCTION 1.01 The Government of Thailand has submitted a request for a Bank loan to assist in financing the construction of the Phasom Dam and saddle dams on the Nan River. The project would provide for the stor- age of flood waters to be used for supplemental irrigation during the dry season on lands of the Central Plain of Thailand. The project would permit the production of a second annual crop on approximately 180,000 hectares of land in the Chao Phya area and approximately 200,000 hectares in the Nan River Valley, lying downstream from the dam. It would also provide a dependable irrigation supply for 400,000 hectares of wet season cropping in the Nan River Valley. 1.02 This report is based on material and project reports prepared and supplied by the Royal Irrigation Department of Thailand and their consultants, Engineering Consultants Inc., on a study of the power potentials made by the Yanhee Electricity Authority, on the findings of several missions which visited Thailand during late 1965 and in 1966. The report was prepared by Messrs. Bartsch, Sicely and Golan. 2. BACKGROUND 2.01 Rice production in Thailand during the 1961/65 period increased, on an adjusted basis making allowance for weather conditions, at about three percent annually, compared with 1.5 percent in the previous five years. Increased acreage was insignificant during the entire period and the rapid expansion in production can be directly attributed to better water control, improved seed and, to some extent, to increased use of fertilizers. Consumption on the other hand has risen at about 2.5 percent annually during the past decade, or at a slightly slower rate than population growth. Currently, Thailand produces an average of about 6.8 million tons of rice annually, of which 1.8 million tons are exported. It is expected that, within 10 to 20 years, all suitable land will be in production and at the present yield would be incapable of maintaining the existing level of exports because of the increase in food requirements for the rapdily expanding population. Were it not for the Chao Phya and Yanhee Projects, financed previously by the Bank, Thailand would be without rice for export by the mid-1970's. The con- struction of these projects, however, only postpones the critical time to the mid-1980's.  - 2 - 2.02 Thailand has a water problem which is twofold in nature. First, excess water falling during the rainy season from mid-May to mid-November, should be controlled to prevent flooding and, secondly, the flood waters should be retained in storage reservoirs for irriga- tion during the dry season to permit second cropping of suitable lands. 2.03 The farmers of Thailand have traditionally used irrigation techniques and, over the centuries, they have constructed a series of canals, ditches, dikes and waterways throughout the Central Plain in an effort to distribute the river water into a labyrinth of rice paddies and channels. In recent years, further improvements have been made and the Bank has made several loans to assist in these phases of development of the area. 2.04 The first of the recent phases in the control of waters in the Central Plain was the construction of the Chainat diversion dam on the Chao Phya River, and a system of main canals which was completed in 1957, which provided a small amount of regulation on the river and its tributaries, and permitted diversion of the river waters for irrigation, flood control, navigation and hydroelectric power. Part of the finance for this development was provided by a Bank Loan (36-TH) of US$ 18 million equivalent, and it started an overall program to improve agriculture in the Central Plain and to use the large amount of water which passes through the area. The Central Plain is a triangular shaped area of flat land with the apex at Chainat Dam and the base along the northern coast of the Gulf of Thailand as shown on the map. 2.05 The second phase of development, financed with a Bank Loan (175-TH) of US$ 66 million equivalent, was the Yanhee Project which provided for construction of the Bhumiphol (Yanhee) Dam on the Ping River, the western-most tributary of the Chao Phya River. Completed in 1964, the dam is now providing hydroelectric power and water con- trol, reducing the hazard from floods and permitting the storage of the monsoon flows for use in the dry season. It is estimated that up to 220,000 hectares of land in the Chao Phya area can be provided with water from this reservoir during the dry season to permit intensifica- tion of agricultural production on this highly productive area. Approximately 50,000 hectares of land has been growing perennial and second crops which are now being irrigated with Yanhee reservoir water. It is expected that the annual increase of such irrigation would range from 11,000 to 22,000 hectares per year. 2.06 The third phase of development is the ditches and dikes pro- ject which includes the construction of systems of dikes, canals, laterals, drains and roads in the Chao Phya area. It will permit the development and irrigation of 800,000 hectares of land for more intensive cultivation. This work, assisted by a loan (328-TH) of US$ 5.6 million equivalent from the Bank, was started in 1963 and is expected to be completed at the end of 1970.  - 3 - 2.07 The project now proposed is intended to fulfill the fourth phase of development for the Central Plain. It calls for the con- struction of the Phasom Dam and auxiliary works, including provisions for a future power plant on the Nan River, the eastern-most tributary of the Chao Phya River. The dam-site is located approximately 60 kilometers upstream of Uttaradit, where the river leaves the mountains. The four phases would control waters of the prinicipal rivers and per- mit irrigation and intensification of agricultural production of sub- stantial amounts of land in the Chao Phya area and in an area proposed to be developed in the Nan River Valley. 3. THE PROJECT AREA General 3.01 Over half of Thailand's farm land is in the central and north zones of the country, with about 85 percent of the area raising a single crop of rice in the rainy season. Fruit, vegetables and some farm crops are grown on the remaining 15 percent. There is almost no second cropping, particularly of rice, because 90 percent of the precipitation occurs in the wet season. 3.02 The shortage of precipitation in the dry season from mid- November to mid-May prevents the raising of additional crops during that period, except under irrigation. Although the soils and climate are suitable for crop growth the year round, irrigation is severely restricted in the dry season by the low flows in the streams and by lack of reservoirs for storing flood waters. 3.03 Four torrential rivers, the Ping, Wang, Yom and Nan, rise in the high mountains of the north, descend through the north and central sections of Thailand, flow through the low delta lands of the Central Plain and empty into the Gulf of Thailand. Soon after enter- ing the Plain, the four rivers join to form the principal river of the country, the Chao Phya. This river flows for 77 kilometers in a single course and then, as is typical of deltaic areas, braids into several channels across the flood plain. These reunite, after being joined by lesser tributaries, and flow into the Gulf of Thailand. 3.04 The irrigable areas lie in the basins of the upper tributary rivers and in the Central Plain, where the Chao Phya and several other smaller projects are located. Reconnaissance surveys of the land and soil of the Plain show that there is a net irrigable area of approxi- mately 1.2 million hectares. The soils of this area are divided into two general groups, the marine clay series which constitutes about 60 percent of the irrigable area, and those other than the marine clay series. Nearly all the marine clay series soils lie south of Ayutthaya (midway down the Central Plain). The marine clays are generally suit- able only for rice; this is grown as a single crop in the wet season.  Other crops are grown on approximately 125,000 hectares of the marine clays largely near Bangkok, where fruits, vegetables and general crops are planted intermittently. On such heavy soils, this requires special farming techniques of modelling the surface into ditches, drains, levees and mounds. These methods of farming are expensive and suitable only for high value crops and normally applicable only to special marketing conditions similar to those found around the larger cities. 3.o5 Of the 500,000 net irrigable hectares of non-marine clay soils, all north of Ayutthaya, an estimated 50,000 hectares are con- sidered best for'raising general crops the year round. Although the soils can also be used to grow rice, they are better suited for other crops. The remaining 450,000 hectares of land are more adapted to rice in the wet season, followed by field crops in the dry season. 3.06 An inverted triangle of land north of Chainat and within the points of the Chainat, Bhumiphol and Phasom Dams, known as the Upper Delta, is potentially irrigable; but the extent of the area and the suitability of soils is only partly known. The Upper Delta area con- sists of the flood plains in the valleys of the Ping, Wang, Yom and Nan Rivers before they join to form the Chao Phya River. Present Status of Cultivation 3.07 In the Central Plain agriculture is comparatively highly developed, due largely to the irrigation distribution systems con- structed during the past fifty years. The main crop is rice, which occupies approximately 80 percent of the land during the flood season. Half of the remaining 20 percent is planted to other crops, mainly 'foodgrains and oilseeds, and half to orchards and gardens. Cropping under irrigation in the dry season has been undertaken increasingly since water stored by the Bhumiphol Dam became available, the area devoted to second-crop rice, sugarcane and vegetables having doubled to 27,000 hectares between 1964 and 1966, while fruit cultivation has increased from 12pPO hectares to over 20,000 hectares in the same period. It is estimated that, for such cropping, the water from the Bhumiphol Reservoir would provide water for up to 220,000 hectares of land. 3.08 The agriculture of the Upper Delta depends almost entirely upon the flooding of the rivers and tributary streams in the rainy season. There is a very small amount of irrigation development which, in some cases, permits dry season cropping, in addition to its main function of more uniformly distributing water supplies during the flood season, but most of the land grows crops only under inundation during the flood season. Since the rainfall is erratic, crop production is very variable, being subject to limitation both by droughts and by excessive floods. Under optimum moisture conditions, about four- fifths of the Upper Delta is cultivated with rice and most of the re- maining land is planted to peanuts, mung beans, soybeans and sesame.  - 5 - Yields in good years are believed to be amongst the best in Thailand, but as there are no accurate statistics, either of yields or of crop acreages, precise figures are not available. Land Tenure 3.09 The 1953 Thailand Economic Farm Survey showed approximately 75 percent of the cultivated land in the Central Plain to be farmer- owned and operated as family units. The remaining 25 percent of the land is leased, usually under crop rental arrangements. The average farm unit is about five hectares and is operated by the owner without hired labor or machinery. 3.10 Data are insufficient to establish whether this land tenure pattern extends to the Upper Delta, but since nearly 90 percent of the farm land of Thailand was shown in the 1953 Survey to be owner- operated, it is unlikely to be very different. Marketing 3.11 After retaining enough for his own consumption and for seed, the farmer sells his rice crop as paddy, either to itinerant buyers or to local merchants who have often sold him goods on credit. He may also sell directly to the numerous rice mills. 3.12 Other crops are sold in the same way. Fruits and vegetables are mainly consumed locally, but some are transported to Bangkok for sale. 3.13 The Government has adopted price stabilization as a means of encouraging rice cultivation. The floor price established for 1966 is 0 800 to 1,050 per metric ton, c.i.f. Bangkok, according to grade. The Government of Thailand also imposes taxes on rice exports composed of Rice Premium and an Export Tax. This produces revenue for the Government and has the effect of lowering the domestic price of rice as compared to world prices. Domestic prices for rice are about one-half the world prices. The Rice Premium is adjusted periodicaIly in accordance with world prices. For further explanation of the Rice Premium, see Annex 1. Transportation 3.14 The Central Plain has good transportation facilities com- prising railroads, highways, feeder roads and navigable canals and rivers. 3.15 The facilities of the Upper Delta are less well developed; they include, however, the main north-south railroad which runs through the area from Uttaradit south to Bangkok and a highway system which connects the area with Bangkok. The Nan River is navigable by river  - 6 - craft fram Uttaradit down to its junction with the Ping River at Nakhornsawan and omnards to Bangkok and the Gulf of Thailand. Agricultural Production 3.16 Statistics of crop production in the area proposed for further agricultural development are not reliable. The best in- formation available, from RID and the Rice Department, suggests that paddy production at present averages about 1.5 tons per hectare for all of Thailand. 3.17 The farm gate price for paddy varies from 0 745 to 0 1,000 per metric ton according to quality and the time of year at which it is sold. Information obtained by RID from the Ministry of Agriculture and supplemented by sample surveys in the area indicates an average price to the farmer of 0 850 per ton. Production costs under existing conditions are estimated at 0 325 per metric ton. 4. THE PROJECT 4.01 The project, which it is proposed the Bank should help to finance, would be the construction of the Phasom Dam and reservoir, together with associated facilities. The work would be completed within five years (see Annex 2). In addition to the construction work, studies would be conducted, one for an irrigation project in the Nan River Valley, and the other for the formulation of a plan for the rapid introduction of second cropping in the northern part of the Chao Phya Plain. A future power project is expected to be con- structed by the Yanhee Electricity Authority (YEA) and would include a powerhouse at the dam site, together with transmission lines, sub- stations and other power facilities to connect with and deLiver power over the power system of the YEA. The YEA would carry out a study (to be completed in 1967) to determine the best timing for installation and the optimum capacity of power generating facilities at the Phasom Dam. Proposed Works 4.02 The principal features to be constructed under the project would be the Phasom Dam, a concrete, flat-slab and buttress-type structure, approximately 60 km upstream from Uttaradit; five earth saddle dams along the rim of the reservoir located 20 km north-west of the main dam site; concrete foundations and provision for penstocks for a future powerhouse; an access road to the dam approximately 60 km long from Uttaradit and roads and bridges in the area of the main dam and campsite; an access road to the saddle dams, construction camp and permanent buildings; an airfield; and facilities for con- struction power and communications. A detailed description of the works is given in Annex 3.  - 7 - L.03 The proposed concrete dam would be approximately 100 meters in height and about 800 meters at the crest elevation of 166 meters. It would provide a reservoir with a storage capacity of 9,000 million m3. The dam would be provided with an overflow crest-type spillway having a maximum discharge capacity of 4,500 m3/second, controlled by four automatically operated radial gates, each 13 meters wide by 6.5 meters high. Four river outlets would be provided through the dam for release of water from the reservoir for irrigation or other pur- poses. The outlets would be three meter diameter steel pipes en- cased in concrete and controlled by hydraulically operated high pressure gates. Provision would be made in the dam to permit the future installation of penstocks for the proposed power plant. 4.04 The five saddle dams would be up to 35 meters in height and would be constructed of compacted earth materials with riprap on the upstream faces. 4.05 The RID is providing transportation facilities to the dam site by a road from Uttaradit, and by an airfield approximately 40 km from the dam site. The road to the main dam is almost finished, except for small amounts of excavation and surfacing. Additional roads would be constructed in the immediate vicinity of the main dam site for camp and construction requirements. Two concrete bridges, one over the Nan River and one over the Paad River, a tributary stream, have been nearly completed. Work on the 15 km road to the saddle dams was started toward the end of 1966. The airfield is completed and in operation. Provision has also been made for the transport of materials and supplies by river to a point about five km upstream from Uttaradit where an unloading, warehousing and storage area has been constructed. From this point, materials would be transported over the access road. The cost of the works already com- pleted is approximately US$ 5 million. 4.06 Satisfactory sources of sand, gravel, rock and earth materials are readily available near the structure sites. Cement, steel, equipment and other items would be transported to the con- struction site by road and boat. 4.07 Bulk power supply for the Central Plain is the responsibility of the Yanhee Electricity Authority, a progressive, well managed utility, with which the Bank has had continual relations since its formation in 1958. Past load growth on the YEA system has been very rapid and studies recently concluded by YEA and its consultants indicate the need for energy sources in 1971 additional to those presently planned or under construction. The Phasom Dam and Reservoir would provide one such source and during construction of the dam a foundation for a power- house and the provision for the installation of future penstocks would be made. The costs of the powerhouse foundation and provision for future penstocks would be included in the project.  -8- Status of Engineering 4.08 Planning, investigations and preparation of the feasibility report for the project were performed by Engineering Consultants, Inc. (ECI), the consultants to the Royal Irrigation Department. The RID would employ ECI to prepare detailed construction drawings, as well as to undertake the responsibility for supervision of contract con- struction and of providing technical assistance and review of that portion of the construction work which would be performed by the RID. In addition, the RID has agreed that a Board of Consultants, consist- ing of three experts to be appointed by RID after consultation with the Bank, would be employed to advise as needed on special problems which might develop during the design and construction of the Phasom Dam. The Board of Consultants would also review periodically the progress of work and approve the basic design assumptions and criteria adopted by ECI. 4.09 The RID would plan and prepare a feasibility study for the proposed irrigation development in the Nan River Valley with the assistance of expatriate personnel comprising as a mininum a planning engineer, a design engineer and an agricultural economist. The RID plans to ask for such specialist assistance from the U.S. Bureau of Reclamation with which it has had a good working relationship over the past 20 years. The RID has agreed to secure the services of these experts not later than the end of 1967 or, if no such experts are avail- able, a consulting firm would be engaged to provide the Department with the consulting services required to complete the feasibility study. 4.10 The study of the northern part of the Chao Phya Plain would be for the purpose of formulating an agricultural development program for the rapid introduction of second cropping. To undertake the study, the Government intends to apply for technical assistance under the Colombo Plan to obtain the services of experts. The Government has agreed that, if by the end of September 1967 no firm commitments can be made for such services, it would proceed to select a consulting finm, or other experts, to undertake the study by not later than the end of 1967. The study would include the improvement of the water distribution systems, layout of drainage systems, land classification, expansion of the road systems, and recommendations for an enlarged agricultural program covering such aspects as cropping patterns, fertilizers, seeds, extension services, agricultural credit and marketing. 4.11 The proposed arrangements for the employment of consultants and technical assistance are satisfactory. Assurances have been obtained from the Government that consultants would be employed as outlined above and that the Bank would be given an opportunity to approve the selection and terms of reference for all consultants. Assurances have also been obtained from the Government that the studies and reports for the Chao Phya area and the Nan River Valley would be completed by not later than the end of September 1969 and the end of December 1969 respectively.  - 9 Construction Cost Estimates 4.12 The cost estimates for the various construction features of the project are based upon preliminary designs prepared by the con- sultants with the assistance of RID. Designs of the major works are in sufficient detail to provide a reasonably satisfactory basis for making work quantity estimates. Costs have been estimated on the basis of unit prices applied to the quantity estimates. The unit prices were established by the consultants in accordance with the most recent experience of RID in performing similar work in Thailand and upon the bid prices obtained for comparable work on the Bhumiphol Dam Project. Although the prices for Bhumiphol work are several years old, up until recently costs for such work have not significantly increased in Thailand. To such total costs have been added adequate provisions for contingencies, supervision and overhead, consulting engineer costs, taxes and duties and interest during construction. The estimates also include the cost of foreign consulting services required to prepare the studies and reports as provided in paragraphs 35 and 36. The cost estimates are reasonable. Details of the cost estimate are given in Annex 4 and are summarized below: Local Foreign Currency Exchange Total Estimated cost (Baht millions) 9h9.3 632.7 1,582.0 In US$ million equivalent 45.7 30.5 76.2 Construction Equipment and Supplies 4.13 A list of the various items and types of equipment and supplies to be purchased for the project and their cost is given in Annex 5. The cost of such equipment, including insurance and freight to Bangkok, is estimated to be approximately US$ 3.9 million. The cost estimates for equipment and supplies are based upon current vendor quotations and the most recent experience of the RID in the purchase of similar items. The equipment requirements were prepared by the RID and are based upon the performance of construction by the RID in accordance with their past methods and practices which have been satisfactory. After completion of the saddle dams, the equipment employed on that work would be used by the RID to start work on the canal systems in the Nan River Valley. No allowance has been made for the salvage value of the construction equipment after completion of the saddle dams. Financing 4.14 The proposed Bank loan would cover about 38 percent of the foreign exchange cost of the project, consisting of imported equip- ment, spare parts, materials, payments to contractors and foreign  - 10 - consulting services, but not interest during construction on the loan. The amount of the proposed loan would be US$ 10 million (O 208 million), which is about 13 percent of the total cost. A US$ 16 million loan would be obtained by the Government from the Bank of Thailand to finance the balance of the foreign exchange cost. The remainder of cost, totalling about $ 1,042 million, would be met by budget allocations. 4.15 The expenditure schedule would be approximately as follows: Millions of Bahts 1966 and Fiscal Year earlier 1967 1968 1969 1970 1971 1972 Total Local Expenditures 100 120 190 290 145 80 24 949 Foreign Expenditures - 105 125 180 120 90 13 633 Totals 100 225 315 470 265 170 37 1582 Equivalent Millions US$ 4.8 10.8 15.2 22.7 12.7 8.2 1.8 76.2 IBRD Loan Millions US$ - 1.8 2.3 2.9 1.7 1.2 0.1 10.0 5. WATER SUPPLY AND REQUIREMENTS 5.01 Records of stream flow on the Nan River at the dam site have been taken since December 1954, providing almost 12 years of continuous and reliable stream flow measurements. Fhrthermore, stream flow records have been maintained since 1938 at Uttaradit, which is approxi- mately 60 km downstream from the dam site. From theser cords, and from the precipitation records, a reasonably reliable estimate of the river discharges extending over a period of more than 25 years was obtained. The average annual stream flow is estimated to be more than 7,000 million m3 at the Phasom Dam site. 5.02 In general, the proposed operation of the reservoir provides for the storage of the monsoon waters during the period July through October for release during the dry months extending from January through April. The Phasom Reservoir of 9,000 million m3 (which is in excess of the annual runoff of 7,000 million m3) would permit the storage of river flows that exceed the average flows and permit them to be carried over and utilized in the succeeding year. This would have been possible in more than 40 percent of the years of record.  5.03 Reservoir operation studies indicate that the Phasom Reservoir would permit the irrigation during the dry season of about 180,000 hectares of rice in the Chao Phya area and 200,000 hectares in the Nan River Valley. Such crops would be in addition to those normally grown during the monsoon season. Besides providing water for agricultural purposes, the Phasom Reservoir could reduce flooding during the monsoon season; could increase the flows during the dry season to alleviate the salinity condition which prevails at Bangkok and adversely affects the municipal water supply of that city; could improve the navigability of the Nan River; and could provide electric power. 5.04 The study of reservoir operations under full project develop- ment, with priority to irrigation use and the 25 years of hydrologic record shows critical water shortages in three years and minor water shortages in four years. These shortages, however, would occur at the end of the dry period and extend into the beginning of the wet period. Such shortages, while reducing the agricultural production, would nevertheless occur at a time of the year when agricultural planting could be adjusted to the water supplies known to be available in the reservoirs. This would substantially reduce losses to the cultivators. Shortages of this frequency and magnitude are accept- able. 6. AGRICULTURAL DEVELOPMENT 6.01 The proposed project would permit the irrigation of 180,000 hectares of second cropping in the Chao Phya area with water from the Phasom Reservoir. This is over and above the 220,000 hectares which would be second cropped with water from the Bhumiphol Reservoir as described in paragraph 2.05. To attain the benefits from second cropping in the Chao Phya area, additional irrigation works over and above those now constructed, or being constructed, would be required. These would include better control facilities and structures on the water distribution system and a complete drainage system to control the groundwater levels which would be affected by the additional water applied for second cropping. Such works would be constructed at a rate corresponding to development of second cropping and are estimated to cost approximately US$ 65 per hectare. Thus, for the 180,000 hectares to be irrigated from the Phasom reservoir, a total of US$ 11.7 million would be invested over a period of 8 to 16 years, and such costs have been taken into consideration in the economic evaluation of the project. In addition, an agricultural development program to assist farmers to rapidly and successfully start second cropping is necessary. Plans for this program would be studied and a report prepared as described in paragraph 4.10. 6.02 In the Nan River Valley, a future project consisting of a diversion dam, main canals and distribution and drainage system is  - 12 - contemplated. Inasmuch as no agricultural, soils or engineering data are available for this development, a feasibility study and report would be prepared as described in paragraph 4.09. It is expected that such a development would provide irrigation for about 400,000 hectares of first crop and 200,000 hectares of second crop in the dry season, using water from Phasom Reservoir. The cost of such a development has been roughly estimated to be US$ 400 per hectare and the development period would extend over 13 years. The water from the reservoir would overcome the adverse effects on first crop yields caused by the short droughts which often occur in June and July after the commencement of the monsoon rains and during the early stages of plant growth. Construction of this development is estimated to begin in 1970 and to be completed in 1982. The timing is reasonable and was based on an acceptable rate of invest- ment commensurate with the resources hitherto allocated to irrigation development in Thailand. The costs and benefits of this development have been taken into consideration in the economic evaluation of the proposed Phasom Dam Project. 6.03 For all areas, the second crop probably would be almost entirely rice in the early years, though an increasing number of farmers may turn to other crops as they gain knowledge of them. Crops which would appear to be suitable include corn, peanuts, soy- beans, mung beans, sesame, sugarcane, cotton, jute and kenaf. An estimate of production costs for rice is given in Annex 6. 6.04 The Thai Government is supporting the diversification of cropping and is making provision for increased agricultural inputs. Up to now, the efforts in this respect have not been satisfactory. The Ministry of Agriculture has not been able to provide the personnel and services which are needed for an effective program. To introduce and expand second cropping on a scale necessary to derive the full benefits from the proposed project, will be a very difficult task to achieve and will require a far greater effort. The additional re- quirements for second cropping over those for the first crop, irrespect- ive of whether rice or other crops are being cultivated, include fertilizers, improved seeds, pesticides, agricultural extension services and credit. Also, because of the short time available between harvest and seed bed preparation, it would be necessary to increase the mechanization of farm operations. A greatly expanded program for all these inputs would be required and assurances have been obtained from the Government that it would promptly take the measures necessary to assure more intensive farming of the areas to which additional water would be supplied. 6.05 In conjunction with the preparation of the studies and reports a program for complete classification of the land of the Chao Phya and Nan River Valley areas is planned. In the Nan River Valley, this has been started, but no significant work has been undertaken in the Chao Phya area. For most effective development of second cropping, it is necessary to know the nature of the soils, the  - 13 - uses to which they are best adapted, the limitation on their use, and the cultural practices most applicable to them. This can be ascer- tained only after the land has been properly classified. The significance of drainage could also be more accurately evaluated, as this undoubtedly would become a significant problem with the greater application of water for second cropping. It is known that the soils are suitable to grow rice, however, if better soils are found which would grow crops of higher value the benefits from the project would be enhanced. The RID has secured from the U.S. Bureau of Reclamation and elsewhere land classification experts who are to be stationed in Thailand for several years, to program and accomplish the work, including the training of Thai personnel. It is anticipated that the program would result in a semi-detailed land and soils classification in accordance with U.S. Bureau of Reclamation standards. The completion of this work is important for the prompt and orderly development of the full benefits of the proposed project and the Government agreed that the work for both the Nan River Valley and the Chao Phya areas should be completed by not later than the end of 1968. 6.06 In the absence of detailed information on the soils of the area, the markets available for upland crops, the receptiveness of the farmers to more intensive cultivation, and the general lack of experience with second cropping in the areas affected, it is, of course, impossible to forecast with any certainty the likely pattern of farm production. For economic studies of the project, it has been assumed that the entire area to be irrigated from the Phasom Reservoir would be used for rice cultivation. This assumption has been made because farmers would, in general, be more familiar with rice cultivation, the returns would represent a minimum condition of benefits and it is known that the soils would, in any case, be suitable for rice growing. A cropping pattern consisting of pred6minantly upland crops with some rice has been studied as an alternative. Annex 7 describes the areas and general types of crops to be irrigated under both assumptions. 7. ORGANIZATION AND MANAGEMENT Construction 7.01 The RID agrees that the Phasom Dam should be constructed by contract under international bidding procedures and that the Bank would be given an opportunity to comment on such awards before they are made. For that portion of the project to be constructed by force account by the RID, substantial quantities of equipment and spare parts would be needed to supplement that which is now available to the Depart- ment. In addition, the RID would purchase supplies and materials re- quired for incorporation into all parts of the project. The RID agrees that all such equipment and supplies would be purchased on the basis of international competitive bidding procedures and major contracts would be awarded only after the Bank has been given an opportunity to comment thereon.  - 14 - 7.02 The RID has substantially completed the work on the access road and has done considerable work on the camp facilities and on the bridges across the Nan River and on the Paad River, a tributary stream near the dam site. The RID would continue the work on the roads, bridges and camp facilities required for its own use and that of the consultant, and would perform any additional work as needed for the camp and roads. The RID would also undertake the con- struction by force account of the saddle dams and access road there- to, and would perform a portion of the excavation for the foundation of the Phasom Dam prior to the time the contract is awarded to an international contractor. The RID has had experience in construction of similar works and is fully qualified to carry them out. The RID would be responsible for operation and maintenance of the project. 7.03 The engineering consultants and qualified experts to be employed would act as advisers and review the construction work per- formed by the RID and assist in the selection of construction equip- ment. The consultants would be responsible for all contract supervision and would be the agents for RID for all contractor relationships and would certify to the appropriateness of the with- drawals from the loan account. Studies and Reports 7.04 In connection with the further studies and preparation of reports, close coordination would be required between the consultants and Government ministries and agencies such as the Ministry of Agriculture, the Royal Irrigation Department, the Land Survey Depart- ment and the Department of Highways at the national and provincial levels. The Ministry of Agriculture would participate in the planning of all agricultural aspects, the RID would take part in the planning of all irrigation works and the Department of Highways would join in the planning of the road systems. 8. BENEFITS AND JUSTIFICATION 8.01 The Phasom Reservoir could provide irrigation for about 180,000 hectares of second cropping in the Chao Phya area and for approximately 200,000 hectares of second cropping in the Nan River Valley area, where it would also provide a dependable irrigation supply for 400,000 hectares of first cropping. In the Chao Phya area, water would be needed from (and benefits accrue to) the Phasom Reservoir only after the water from Bhumiphol Reservoir has been ily utilized for 220,000 hectares of second cropping. Likewise in the Nan River Valley, the water cculd be used and benefits realized from the Phasom Reservoir in accordance with the rate at which construction is completed for the irrigation works.  8.02 At full development of the 180,000 hectares of second crop rice in the Chao Phya area the annual gross value of production at farm prices is estimated at US$ 18.0 million. Production nsts, including agricultural services, are expected to be about US$ 5.9 million. Allowing for operation and maintenance expenditures, the net value of production at farm prices would be about US$ 11.6 million. For the computation of economic benefits the value of production was estimated on the basis of world market prices. Thus, benefits from the project would be equal to the net value of rice produced at farm prices, plus export tax collection on all rice produced. The net value of incremental annual production to the economy at full development would consequently be about US$ 24.6 million. Similarly, when the Nan River Valley area is fully developed, the net annual value of production at farm prices would be about US$ 12.8 million and net benefits to the economy US$ 27.3 million. The total annual net benefits from the Chao Phya and the Nan River Valley areas would thus be about US$ 51.9 million. 8.03 After making allowance for domestic consumption of rice, it is expected that approxinately 290,000 and 335,000 metric tons of rice from second cropping would be available for export from the Chao Phya and Nan River Valley areas respectively. Tax collections in the form or rice premium and export taxes (Annex 1) are estimated at US$ 10.7 million and US$12.4 million from rice produced in the Chao Phya and Nan River Valley areas respectively. The combined production increase of the two areas at full development would thus result in a 33 percent increase in the volume of rice exported from Thailand and an equal percentage increase in rice tax collections over the 1965 level. 8.04 Some of the assumptions on which the above benefits have been calculated are not yet as well documented by definitive studies as is normally required by the Bank. Accordingly, it has not been easy to decide how to calculate the economic return on the investment in the project, or whether to postpone consideration of the project until the necessary studies have firmed up the assumptions. There are arguments on both sides. The studies that have not been carried out are the engineering, land classification and feasibility studies of the irriga- tion in the Nan River Valley. These are important. These consider- ations argue for postponement of the project. On the other hand, the arguments against postponement are that the farmers of Thailand are by tradition adapted to irrigated agriculture, and that the Bank, during the past 15 years, has had sufficient experience in Thailand to be con- fident that the RID can construct and operate the project efficiently, preparations for construction have been started and have gained momentum, and to defer the work would mean dispersion of a team fully geared to proceed, would diminish the momentum of accomplishment now acquired, and would impair the investment already incurred. 8.05 In order to arrive at a recommendation, the economic rate of return on the project was calculated on various assumptions, starting with a minimum (and in fact unrealistic) assumption of the possible  - 16 - benefits, to indicate the maximum risk involved in proceeding with the financing forthwith. This calculation is made on the basis that the water stored in the reservoir and the river regulation pro- vided by the project is utilized solely for greater production of rice on 180,000 hectares of rice in the Chao Phya area. It takes no credit for: a) benefits for Nan River Valley irrigation; b) benefits from any more valuable crops than rice; c) benefits from electrical generation; d) benefits from flood control; e) benefits from navigation; and f) benefits from salinity control. It has been assumed that the development of second cropping could vary from 11,000 to 22,000 hectares per year. On these assumptions, the rate of return on the US$ 80 million investment in the dam and the additional irrigation works in the Chao Phya area would range between 6 and 10 percent, depending on the rate of development of second cropping when the benefits are discounted over the economic lift of the project. 8.06 If more realistic assumptions are used, and credit is taken for benefits from the Nan River Valley irrigation, the return increases to between 11 and 14 percent. If the second crops in both areas are assumed to be higher value crops than rice, the return would increase to between 12 and 15 percent. 8.07 Preliminary studies of a proposed power installation indicate that power facilities of 150 to 300 MW at the dam would improve the economic returns from the project. These studies are based upon a comparison with equivalent thermal generating facilities. As the complete utilization of all the available water from Phasom Reservoir for irrigation purposes may require 10 to 30 years, depending on the rate of agricultural development, the reservoir water supplies could be used for power development during this period to assure the best returns from the project. Assurances have been obtained from the Government that it would cause YEA to carry out further studies of the power project under terms of reference as agreed with the Bank to determine the best timing for installation and the optimum capacity of power generating facilities at the Phasom Dam. In the early years of the project, until the irrigation water demands are controlling, the reservoir water releases should be scheduled to obtain the optimum power benefits. 8.08 Benefits from flood control, navigation and salinity control would add something to the project returns. Taking all these into account, it has been concluded that the range of economic returns in prospect ranging from a minimum of six percent under the most unfavor- able assumptions to a maximum of over 15 percent under the more favor- able assumptions justify proceeding with the financing of the project forthwith.  - 17 - 9. CONCLUSIONS AND RECOMMEINATIONS 9.01 The project is an essential and integral part of the overall plan of agricultural development for the Central Plain of Thailand. It would assist in controlling the floodwaters, provide a dependable water supply during the dry season and permit more intensive cultivation of the land in the Chao Phya area, as well as in the future irrigation development in the Nan River Valley. The additional water supplies impounded by the Phasom Dam would permit second cropping of the areas, enable greater crop yields to be obtained and substantially increase the value of Thailand's agricultural production and volume of exports. 9.02 To realize the benefits attributable to the Phasom Dam Project from the Nan River Valley would require the planning and construction of a suitable project in that valley. Therefore, it would be necessary to carry out an energetic planning and development program, under which the required irrigation works such as diversion dams, canals and distribution systems would be constructed as soon as practicable. Since such planning and construction work would, to some extent, have to be carried out simultaneously with the construction activity on the Phasom Dam, the programs must be phased in such a manner as to permit optimum benefits within the limits of the national budget and the capability of the RID. 9.03 A final determination of the area of land on which the waters of the Phasom Reservoir may most effectively be utilized could be made only after the classification of all potential lands is completed. This work has not progressed to a point where a reliable conclusion could be reached. The land classification should be carried out as soon as practicable for proper planning of crop patterns, prompt and effective use of water and to obtain the maximum benefits as quickly as possible. 9.o4 Optimum benefits from the Phasom Dam Project are dependent upon a rapid rate of development of second cropping and on the production of crops which can be marketed readily at profitable prices. It is apparent from the middling results obtained from current efforts to intensify cropping in the Chao Phya area that a more forceful and effective program will have to be devised to reach and maintain a satisfactory rate of development. Special measures must therefore be taken to encourage the Thai farmer to farm his land holdings in a more intensive manner through assistance in various agricultural programs, including extension service, credit, seed improvement, pest control, marketing and other appropriate measures. The proposed study and report should establish the most effective manner in which to reach these objectives. 9.05 The RID, which has successfully completed or has nearly com- pleted the work on four previous loans made by the Bank, has shown in the past appreciable ability in the execution of water resource projects in Thailand. The organization is well managed and staffed with a capable professional staff. It has a number of projects successfully  - 18 - underway in the planning, construction and operation stages. With the assistance of consultants and special experts, complex and difficult projects comparable to the Phasom Dam have been undertaken and successfully completed. The RID should be equally successful with the proposed project. 9.06 The lack of adequate information on the land rescurces, the problems associated with attaining an acceptable rate of second cropping and corresponding benefits, and the necessity to make a number of broad judgments as to costs, crcp yields, market potentials and rates of expected development on the project have made the appraisal of this project less conclusive than for other projects. The performance of the RID on similar projects and the fact that under extremely pessimistic assumptions the economic return would not go below six per- cent have been essential factors in reaching the conclusions herein. In spite of the uncertainties, the project appears to be one which can be expected to be very successful and helpful to the economy of Thailand. 9.07 The project is suitable for a Bank loan of US$ 10.0 million for a term of 20 years, including a grace period of 6 years. March 23, 1967  PHASOM DAM PROJECT Rice Taxes and Export Price of Rice 1. The Government of Thailand maintains a flexible Rice Pre- mium and Export Tax on rice exports. These taxes which are the principal ones levied on the agricultural sector, have the dual purpose of providing revenue and insulating the price of domestically con- sumed rice from price fluctuations of this crop on the world market. Although they apply only to exported rice, these taxes strongly affect domestic prices which are currently about half of the export price. Since rice farmers who are the principal users of irrigation water do not pay water charges, the Rice Taxes in fact serve as a substitute to water charges which are normally paid by farmers in similar projects elsewhere. 2. It is estimated that during fiscal year 1964/65 the Rice Premium averaged 0 663 and the Export Tax 0 104 per metric ton on all grades of milled rice exported. Assuming an effective milling yield of 70 perc_nt, this represents an equivalent tax level of g 537 per metric ton of paddy. With average yields to be realized in the project area from dry season rice crops estimated at 2.8 metric tons of paddy per hectare, farmers would in effect be paying an indirect tax of 2.8 x 0 537, or approximately 5 1,445 per hectare. 3. Assuming an average price of 0 745 per metric ton of paddy and a milling yield of 70 percent, the average 1965 export price on one metric ton of rice FOB Bangkok is composed of the following: Bahts Percentage Farmer's share 1,063 47 Rice Premium 663 29 Export Tax 104 767 5 34 Intermediaries, milling, transport 430 19 Average export price per metric ton of rice FOB Bangkok 2,260 100 (US$109) 4. The Rice Premium is adjusted periodically in accordance with world market prices. Estimated collections from the Rice Premium and Export Tax during fiscal year 1964/65 were $ 1,445 million. Assuming that the present levies of 0 767 per metric ton represent a reasonable expected average, the revenues attributahle to Phasom Dam Project at full development would be about 0 223 million from rice exports originating in Chao Phya and % 258 million from the Nan River Valley, making a total of 0 481 million.  THAILAND: PHASOM DAM PROJECT PROPOSED CONSTRUCTION SCHEDULE DESCRIPTION 1966 1967 1968 1969 1970 1971 J A S O ND JCFIM AMJ J AS OND J FIMA_MJ _A_ e JA F M|A|MJJASO ND J FMAMJJASONDJ|F|M|A|M|J|JASOND PHASOM DAM (CONTRACTOR CONSTRUCTION) CONSULTANT LETTER OF INTENT PLANS AND SPECIFICATIONS-DRAFT REVIEW AND APPROVAL CONSTRUCTION DRAWINGS AND SUPERVISION FINAL REPORTS CONTRACTOR ISSUE INVITATION AND OPEN BIDS CONTRACT AWARD A APPROVAL (NOTICE TO PROCEED) CONSTRUCTION MOBILIZATION (PLANT AND EQUIPMENT) DIVERSION AND CARE OF RIVERSTRSOINWAE ~RID Excavation- EXCAVATION -DAM, PP FOUNDATION DAM, SPILLWAY, OUTLET WORKS AND POWERHOUSE FOUNDATION COMPLETION (CLEANUP AND MOVEOUT) SADDLE DAMS (RID CONSTRUCTION) CONSULTANT LETTER OF INTENT PLANS AND SPECIFICATIONS CONSTRUCTION SUPERVISION FINAL REPORTS CONSTRUCTION PREPARATION WORKS (CAMP AND FACILITIES) PURCHASE AND MOBILIZE EQUIPMENT DAMS COMPLETION (CLEANUP AND MOVEOUT) z z NOTE Approximate flood season, July through October IBRD - 3334 October IBRD - 3334~~~~~~~~~~  ANNEX 3 Page 1 PHASOM DAM PROJECT Description of Works 1. The engineering wqorks comprising the project would include the following: the Phasom Dam including spillway and outlet works, minimum facilities to permit the future installation of power facilities at the Dam, five earth saddle dams, access roads and bridges, airfield, trans- mission lines and substations to provide construction power at the dam site and camp, a construction community and other related facilities. Phasom Dam 2. The Phasom Dam would be a concrete flat-slab and buttress type structure. The dam would rise approximately 100 meters above the stream bed. The length of the concrete section would be approximately 800 meters at the crest elevation of 166 meters. Approximately 900,000 m of concrete would be required for the dam and appurtenant structures. The buttresses of the dam would be spaced approximately 7 1/2 meters center to center. In the river section, eight buttress spaces would be utilized for a radial-gate controlled spillway which would also accommodate four individual river outlet conduits so that the spillway and outlet works discharges would utilize the same apron and stilling basin. Adjacent to the spillway outlet works section on the left side of the dam would be a section including intakes for possible future penstocks utilizing 18 buttress spacings; In the areas used for out- let conduits and penstocks, the dam would be mass concrete to sufficient height to support the buttress sections. Underdrains t-ould be provided -here necessary to relieve uplift pressures. Foundation grouting and drain holes would be provided where required, to seal the foundation and provide pressure relief. A continuous concrete bearing section would be entrenched in the foundation rock at the upstream heel of the dam. A fault zone in the foun- dation near the right abutment would be excavated, filled with concrete and otherwise treated to be watertight and provide the support needed by the dam. A concrete parapet slightly over a meter high would be provided on the up- stream side of the roadway across the dam crest. SpillWay 3. The spillway would be an overflow crest type, 52 meters wide with a crest at elevation 154 m. and with a stilling basin extending downstream from the dam. Control would be by four 13.0 meter wide by 6.50 meter high automatic, electrically operated radial gates with provisions for manual operation. The spillway would be designed to limit the discharge to 3,000 m /Second assuming a 100-year flood with a peak inflow of 5,b00 m3/Second and also would limit the surcharge above normal water surface elevation 160, to 6 meters when passing the spillway design flood with a peak inflow of 8,000 m3/Second. The maximum discharge of the spillway would be b,500 m3/ Second with the water surface at elevation 165.7/ River Outlets L. Four individual river outlets would be provided throught the dam, each consisting of a 3.0 meter diameter steel conduit encased in concrete  ANNEX 3 Page 2 regulated by two hydraulically operated high pressure gates 2.4 meters by 3.0 meters high. The upstream entrance to the river outlets would be pro- tected from large logs and debris by a large-opening, steel-grill trashrack. The discharges from the river outlets would be through the downstream spil- lway-face slab. The outlets would each have a discharge varying from lb5 m3/Second with a nearly empty reservoir at elevation 112, to 225 m3/Second with a full reservoir at elevation 160. The outlets would be used to make irrigation releases. Future Power Facilities 5. Provision for a future power installation at the dam would be made by constructing the concrete foundations up to elevation 71.5 meters above mean sea level for the powerhouse and installing b intakes and trashrack structures on the upstream face of the dam so that at some future time the powerhouse could be completed without unwatering the foundation and the power penstocks could be installed without removtng th6 water from the resbrvoir. Approximately 50,000 m3 of concrete would be required for these works. Saddle Dams 6. Five saddle dams up to 35 meters in height would be constructed approximately 20 kilometers west northwest of the main dam site at low points in the rim of the reservoir. The saddle dams would be constructed of approx- imately 3 million cubic meters of compacted earth fill covered on the up- stream side with riprap. The top of the saddle dams would be at elevation 168.0 and they would have a top width of 5 meters suitable for use as a maintenance road. The side slopes of the saddle dams would be constructed to 2 1/2 to 1 slopes, and the dams would be provided with a cut-off trench as required in the foundation. The total volume of the saddle dikes is approx- imately 3 million cubic meters. Access Roads 7. Construction of an access road from Uttaradit to the dam site, a distance of approximately 60 kilometers, has been substantially completed. A branch road, 15 kilometers in length taking off from kilometer 28, would be needed for access to the saddle area. A portion of this road has also been constructed. A short distance downstream from the dam site two concrete and steel bridges are nearing completion, one over the Nan River and one over the Paad River, a tributary stream. Under the project all roadwork and bridges would be completed and additional road facilities would be provided at the dam site. Construction Power 8. It is estimated that the peak construction power requirements will not exceed 5,000 k.w. For this purpose it is expected that the Yanhae Elec- tricity Authority would construct a 69 k.v. transmission line from the YEA system at Uttaradit to the dam site. The 69 k.v. tie line would be in addi- tion to any high voltage interconnection which would be provided when the  ANNEX 3 Page 3 Phasom power plant is constructed. The line would also provide a permanent source of power for operation of project facilities, including operators camp, after construction is completed and before the local power facilities are installed in the dam. Construction Camp and Other Facilities 9. The project would include the construction of complete camp facil- ities at the dam site. Buildings to be constructed would include those ne- cessary for administration, office, and warehousing use as well as other service buildings and housing for professional and laborer staff. All sup- porting facilities including roads, streets, water systems, power facilities and other utilities would be provided for the camp site. The RID would con- struct the camp facilities for its use and for the consultant's use. The Civil Works contractor for the main dam would construct all facilities needed for his use.  ANNEX 3 Page 4 STATISTICAL DATA ON DAM AND RESERVOIR Reservoir Sediment Storage 1,080 million m3 Dead Storage 170 million m3 Minimum Operating Pool, for power El. 110 1,000 million m3 Minimum Operating Pool, for irrigation El. 96 300 million m3 Operating Storage, for power El. 160 8,000 million m3 Operating Storage, for irrigation El. 160 8,700 million m3 Total Storage, El. 160, top of spill-way gates 9,000 million m3 Total Storage, El. 165.7 10,500 million m3 Surcharge Storage 1,500 million m3 Dam Length 800 meters Height (above streambed) 100 meters Crest Elevation 166 meters Surcharge and Freeboard Height 6 meters Spillway Gate - Crest (sill) Elevation 154 meters Spillwaay Gates, 13.0 x 6.50 meters 4 Capacity at Elevation 160 1,600 m3/Second Capacity at Elevation 165.7 4,500 m3/Second Outlet Works Intake Sill Elevation 91 meters Outlet Works Gates, 2.4 x 3.0 Sets 4 Capacity at Elevation 112 580 m3/Second Capacity at Elevation 160 900 m3/Second Penstock Intakes-Sill Elevation 91 meters Penstock Intakes-Number provided 4 Concrete in Dam 912,300 cubic meters Excavation for Dam 1,060,000 cubic meters  ANNEX 4 PHASOM DAM PROJECT Estimate of Costs Local Costs Foreign Exchange Total Costs Cost Bahts US$ Bahts ----------- Millions------------- Phasom dam, spillway and outlets 413.0 13.3 688.6 Powerhouse foundation structure and intakes 29.0 .8 45.6 Gates, trashracks, outlet pipes and other materials 3.3 1.0 24.1 Contingencies 20% 89.2 3.0 151.4 Saddle dams 35.4 1.8 72.0 Land, land rights and resettlement 38.8 - 38.8 Clearing reservoir area 18.0 .4 26.5 Electric power and distribution systems 4.2 .5 14.6 Roads and Streets and bridges 78.0 78.0 RID camp and utilities 28.6 .3 34.9 Transport equipment - .8 16.6 Contingencies 15% 30.3 .6 42.8 Engineering and administration 106.5 3.5 179.1 Investment for economic analysis 1/ SUB-TOTAL 874.3 26.0- 1,413.0 Local taxes and duties 2/ 75.0 - 75.0 Interest during construction - - 4.5 94.0 GRAND TOTAL 949.3 30.5 1,582.0 1/ Bank loan equal to approximately 38 percent at this amount. 2/ Simple interest on foreign exchange costs @ 6 percent. Not included in proposed Bank loan.  ANNEX 5 Page 1 PHASOM DAM PROJECT Equipment and Supplies for Construction No. Unit Cost Total Cost Item Equipment Required (CIF Bangkok) US$ US$ PHASOM DAM I. TRANSPORTATION EQUIPMENT A. For Cement (Takli-Phasom) (250,000 tons) 1 Tractors 40 16,000 640,000 2 Tank trailers 36 9,000 324,000 3 Spare parts 15% - 1441,600 4 Silo's 3,500 tons 3 50,000 150,000 5 Silo equipment Lump Sum - 75,000 Sub-total 1,333,600a/ B. For Other Materials 1 Tractor and 25 ton lowbed 1 25,000 25,000 2 Tractor and 50 ton lowbed 1 29,000 29,coo 3. Tractor and 15 ton semi- trailer 2 24,000 48,000 4 Tractor and 15 ton van 1 28,000 28,000 5 21,000 GVW flatbeds h 5,000 20,000 6 7,000 lb. Service van truck 4 5,000 20,000 7 7,000 lb. Pick-up 1 3,000 3,000 8 30,000 lb. Wrecker truck 2 30,000 60,000 9 Stationwagons 2 3,500 7,000 10 Field jeeps 2 4,000 8,000 11 Fork lifts 2 8,000 16,000 12 Marine miscellaneous Lump Sum 80,000 80,000 13 Spare parts - 36,000 Sub-total 380,000=.' C. For Personnel 1 Cars and jeeps 20 4,000 80,000 2 Motor-cycles 10 500 5,000 3 Ambulance 1 6,000 6,000 4 Spare parts - 5,000 Sub-total 96,00Qo /  ANNEX 5 Page 2 No. Unit Cost Total Cost Item Equipment Required (CIF B2ngkok) US$ US$ PHASOM DAM Cont'd D. For Construction (Warehouse, Camp, Shop) 1 Flatbed (21,000 lbs) 2 5,000 10,000 2 Pick-up trucks 3 3,000 9,000 3 Water-truck 1 9,000 9,000 4 Fork-lift 1 8,000 8,000 5 Mobile crane (50 ton) 1 80,000 80,000 6 Spare parts - 7,500 Sub-total 123,500 II. EQUIPMENT FOR CAMP FACILITIES 1 Carpenter shop Lump Sun 10,000 10,000 2 Electric shop Lump Sum 25,000 25,000 3 Machine shop Lump Sum 5,000 5,000 b Hospital Lump Sum 10,000 10,000 5 Office Lump Sum 10,000 10,000 6 Laboratory Lump Sum 10,000 10,000 Sub-total 70,000e GRAND TOTAL PHASOM DAM 2,003,100 SADDLE DAMS I. CONSTRUCTION EQUIPMENT 1 20 c.y. Scrapers 8 58,ooo L6b,000 2 15 c.y. Dump trucks 5 28,000 1bO,000 3 D8 - Dozers (270 h.p.) 5 54,500 272,500 b D7 - Dozers (180 h.p.) 3 35,000 105,000 5 10 c.y. Dump truck 3 21,000 63,000 6 Front end loader 1 21,000 21,000 7 2 1/2 yd shovel 1 75,000 75,000 8 2 1/2 yd dragline 1 75,000 75,000 9 Sheepfoot rollers 2 5,000 10,000 10 50-ton pneumatic roller 1 8,000 8,000 11 Water truck 3 9,000 27,000 12 Lub truck 1 10,000 10,000 13 Air compressors Lump Sum 40,000 h0,000 1l Pumps Lump Sum 8,000 8,000  ANNEX 5 Page 3 No. Unit Cost Total Cost Item Equipment Required (CIF Bangkok) US$ US$ SADDLE DAMS Cont'd I. CONSTRUCTION EQUIPMENT Cont'd 15 Field jeeps 2 4,000 8,000 16 Motor graders 3 12,000 36,000 17 Flatbed trucks (21,000) 2 5,000 10,000 18 Miscellaneous Lump Sum 30,000 30,000 19 Spare parts - 210,000 f/ Sub-total 1,612,500- II. EQUIPMENT FOR CONSTRUCTION FACILITIES 1 Carpenter shop Lump Sum 2,000 2,000 2 Electric shop Lump Sum 2,000 2,000 3 Blacksmith shop Lump Sum 2,000 2,000 4 Machine shop Lump Sum 2,000 2,000 5 Repair shop (Heavy duty) Lump Sum 20,000 20,000 6 Lub and tire shop Lump Sum 6,ooo 6,000 7 Hospital (First aid only) Lump Sum 2,000 2,000 8 Office Lump Sum 2,000 2,000 9 Laboratory Lump Sum 10,000 10,000 Sub-total 48,000 III. MISCELLANEOUS 1 Motor cycles 6 500 3,000 2 Minor items Lump Sum - 70,000 Sub-total 73,000 GRAND TOTAL SADDIE DAMS 1,733,500  ANNEX 5 Page 4 No. Unit Cost Total Cost Item Equipment Required (CIF Bangkok) US$ US$ CENTRAL OFFICE AT EANGKOK 1 Cars, jeep, stationwagon 10 4,000 40,000 2 Office supplies Lump Sum 30,000 30,000 3 Shops Lump Sum 40,000 40,000 4 Spare parts 12,000 12,000 Sub-total 122,000_/ TOTAL RID DOLLAR REQUIREMENTS FOR EQUIPNENT AND SUPPLIES US$ 3,858,60o NOTES: a - This cost is already included in cement cost of the project estimate. b - This cost is already included in cost for Transport equipment of the project estimate. c - Same as b. d - Same as b. e - This cost is already included in cost for RID Camp and Utilities of the project estimate. f - This cost is already included as a cost for Saddle Dams in the project estimate. g - Same as f. h - This cost is already included in the project estimates as Transport Equipment except cost of fuel and oil which is included in various items of the project estimate. i - Same as h.  ANNEX 6 PHASOM DAM PROJECT Estimated Production Costs for Rice Bahts per ha. Current basic production cost 325 Fertilizers (16:20:0) 125 Kg per ha at 0 1,900 per ton) 238 Contract Cultivation (