for THA/84/002



Sacha Sethaputra

March, 1988.

Computer Files Directory
for this Document
March 17, 1988

File NamesProgramsDescriptions
PWT.RWWord RamaFront Cover
TITLEWord Star Pro.4Inside Cover to page vi
PWIANGWord Star Pro.4Chapters 1,2,3 + References + List of Abbreviations + Appendix A
PWAPPAT1.WK !Lotus with SQZTable A1
PWAPPAT2.WK !Lotus with SQZTable A2
READMEWord Star Pro.4This directory



  1. Weirs and Hand Drilled Wells are suitable small scale irrigation facilities for further development in Phu Wiang watershed.

  2. For weirs, it is important to identify group of beneficiaries before site selection and other technical considerations.

  3. For promotion of hand drilled wells, revolving fund is promising. However there are always uncertainties involved in ground water utilization. At this early stage it is advisable to promote hand drilled wells on trial scale to test their applicability before any larger scale promotion is done.

  4. Design and construction procedure for weirs and hand drilled wells are readily available in form of manuals (Appendices B and C). These manuals can be used for large scale development.

  5. Kor Chor Chor Program, Kor Sor Chor Program and People Volunteer Weir Program (references 2, 3 and Appendix D) are three separate government programs that should be pursued for long term development of weirs. To obtain assistance from these programs, weir construction projects must be initiated at the Tambon councils. This is best done in form of 5 years Tambon development plans. The Local Advisory Committee is a good entry point for the THA/84/002 project to motivate the target Tambon councils.

  6. Existing underutilized weirs, small reservoirs and canals should be improved on case by case basis. Only those where sufficient number of beneficiaries are enthusiastic should be considered for improvement. Some form of cost sharing should be used to gauge the beneficiaries enthusiasm.


  1. Natural fish ponds (as communal facilities) and fish ponds in paddies (as private facilities) should be promoted right away.

  2. To promote natural fish ponds, fish fingerlings should be provided to villages where substantial water bodies (man-made or natural) exist.

  3. To promote fish ponds in paddies, audio-visual aids (such as that in the Attachment--a video cassette) and farmer study tour should be organized by the project. Contact Volunteers (CV) should be used as interface between the project and the target farmers. Fish ponds in paddies should be promoted together with hand drilled wells.


  1. Improperly constructed feeder roads are causes for excessive erosion. To minimize erosion, bare soil surface caused by road construction should be covered by plantation or riprap. Where feeder roads obstruct natural drainage pattern, culverts should be used generously to minimize flow obstruction.

  2. Beneficiaries should be encouraged to participate in feeder road development to minimize the difficulties in right of way and land related issues.

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1.1 Types of Facilities and Suitability
1.2 Hand Drilled Wells

1.2.1 Construction Procedure
1.2.2 Selection of Beneficiaries and Sites

1.3 Diversion Weirs

1.3.1 Construction Procedure
1.3.2 Selection of Beneficiaries and Sites
1.3.3 Coordination with Other Units
1.3.4 Areas Stand to Benefit from Weirs Development
1.3.5 Improvement of Existing Systems
1.3.6 Watershed Management


2.1 Types of Fish Pond
2.2 Suitability to Phu Wiang
2.3 Natural Fish Ponds

2.3.1 Procedure for Design, Construction, Selection of Beneficiaries and Sites
2.3.2 Coordination With Other Units

2.4 Fish Ponds in Paddies

2.4.1 Construction Procedure
2.4.2 Selection of Beneficiaries and Sites
2.4.3 Coordination with Other Units


3.1 Construction Procedure
3.2 Selection of Beneficiaries and Sites
3.3 Coordination with Other Units



APPENDIX A Selection of Small Scale Irrigation Facilities

APPENDIX B Construction Manual for Hand Drilled Wells (in Thai)

APPENDIX C Construction Manual for Weirs (in Thai)

APPENDIX D People's Volunteer Weir Program

APPENDIX E Managing Weirs in Small Watersheds--Research Issues in Northeast Thailand

APPENDIX F Policy, Objectives and Procedure of the Village Fishery Program, the Royal Fishery Department (in Thai)

APPENDIX G Term of Reference

APPENDIX H Other Recommendations Made Before the Preparation of this Report

ATTACHMENT Video Cassette on Fish Ponds in Paddies by ATA (VHS format)


This report is a result of two months national consultant in agricultural engineering according to the term of reference in Appendix G.

The report is organized such that it follows the outline set by the term of reference. Small scale irrigation facilities, fish ponds and feeder roads are separately discussed in their respective chapters. Each chapter starts with discussions on types of available facilities, followed by selection of facilities suitable to Phu Wiang conditions. It then discusses each selected facility separately in term of the procedures for design and construction, selection of beneficiaries and coordination with other units.

The report offers practical recommendations without attempt to discuss background theory. In general, recommendations were reached from considering the following three factors.

  1. Physical constraints of the Phu Wiang watershed. These constraints are obtained from literature review, results of other studies, field visits and field data collection by the consultant.

  2. Nature of the THA/84/002 project obtained during the period of consultancy through meetings and discussions with project personnel.

  3. Consultant experience from other areas of the Northeast.

Appendix H contains recommendations and communication made during the period of consultancy before the preparation of this report.


Within the scope of interest of this report, there are three specific characteristics of the watershed that form the basis for the outcome recommendations. They are as follows.

  1. Available land for rice paddy per family is less than the northeast average (Dr. Utai Pison's RRA report on Phu Wiang and private discussion on March 10, 1988.), and hence become more precious than normal.

  2. Rice yield per area is better than the northeast average (reference same as above) due to fertilizer rich sediment washed from upstream. Fertilization of paddy is therefore not a constraint.

  3. The area is relatively far from important market outlets for agricultural products. Markets available are for local demands.

The implication from the first item is that any development that involve taking lands from many small farmers stands more chance of encountering land related obstacles which are difficult to resolve. Such developments are for example, construction of small reservoirs and feeder roads. The second item implies that irrigation (in contrast to fertilizer) is attractive from farmers' point of view-- and hence more demand for small scale irrigation facilities. Since Phu Wiang agricultural products (rice, fish, vegetable, chicken, silk and etc.) are not different from those normally available elsewhere*, the third item implies that there are limitation to intensive promotion (i.e. promotion beyond subsistence level). Hence overpromotion can occur and must be watched closely because it can erode confidence farmers have in the project.

Small scale irrigation facilities, fish ponds and feeder roads eventually relate to effort to diversify income from agricultural products. The third item above also implies that development of these facilities should be done iteratively taking into considerations the Phu Wiang physical limitations, market limitation and opportunity, and other changing socio-cultural factors.

* On the other hand, Phu Wiang is different from others in its forest related products. Hence forest utilization for income diversification is justified if it can be done in an ecologically sustainable way. The agro-forestry approach of the project seems logical and attractive.


1.1 Types of Facilities and Suitability

Available small scale irrigation facilities (SSIF) are as follows:

  1. small reservoir,
  2. diversion weir,
  3. deep well,
  4. hand drilled well,
  5. dug pond, and
  6. shallow well.

Descriptions of these SSIF are described in Appendix A.

In order to determine the suitable facilities for further development in the Phu Wiang watershed area, a decision matrix was constructed. Factors affecting suitability considered in the matrix are: investment cost, area inundated by water, service area, compatibility with farmers in construction, operation and maintenance, storage volume, susceptibility to salinity and availability of construction manual. Details are discussed in the Appendix A. Results of the analysis reveal that

  1. diversion weirs, and
  2. hand drilled wells

are suitable for further development in the Phu Wiang watershed area.

Weirs and hand drilled wells play complementary role in promoting irrigation in Phu Wiang. Weirs serve rice paddy areas close to the streams for supplementary irrigation, provide water for fishery, dry season vegetable growing, and domestic uses. Hand drilled wells serve other low lying areas unreachable by weirs. They can provide water for fish ponds (supplementary), vegetable growing, and domestic uses. In term of management by the users or benefiting farmers, weirs are managed collectively by groups of farmers, while hand drilled wells are managed by individual farm families. Both of these facilities can be constructed using village labor and locally available technology.

1.2 Hand Drilled Wells

1.2.1 Construction Procedure

Simple design and construction procedure is available in form of a manual (Appendix B). Drilling equipment is also described in the manual. This drilling equipment can be made locally or can be purchased (to purchase, contact Dr. Wichai Sriboonlue of the Faculty of Engineering, Khon Kaen University).

1.2.2 Selection of Beneficiaries and Sites

Since hand drilled wells are family oriented, the decision to drill rest upon the individual family. The incentive to have hand drilled well may be due to the desire to have convenient source of water for household use, fish ponds or economic motives such as vegetable growing for sale. As such, beneficiaries can not be selected but voluntary. As for site, the beneficiaries will select the well sites since the wells are their private properties.

Hand drilled wells, with respect to their promotion, are quite similar to rainwater jars where Revolving Fund (It is a kind of seed money given to village committee. It is available for loan to selected villagers. The money must be given back and used to fund further construction of jars for other villagers.) has been applied successfully. However at this early stage, it is not advisable to apply revolving fund to hand drilled well. Instead the following steps are recommended as a test to see if hand drilled well will be successful. The steps that should be taken by the THA/84/002 project are:

  1. The project acquires a set of hand drilled well equipment.
  2. Through the village volunteer monthly meetings, news should be announced that the drilling equipment is available for loan.
  3. Demonstration should be arranged to show well drilling technique in some selected villages. Khon Kaen University staff can be contracted to do this.
  4. If it is found that the equipment is popular, revolving fund should then be considered for serious promotion of hand drilled wells.

1.3 Diversion Weirs

1.3.1 Construction Procedure

Design and construction procedure in a form of manual is available (Appendix C).

1.3.2 Selection of Beneficiaries and Sites

Utilization of weirs by farmers depends critically on beneficiary and site selections. In the following steps, selection of beneficiaries is described first. This eventually leads automatically to the selection of sites. Experience indicate that site selection subject to technical suitability is of secondary importance to selection of beneficiaries. The following paragraphs described steps involved in the selection of beneficiaries.

The following steps were the taken from Khon Kaen University (KKU) experience in weir development. They are described in more details in reference 1. In these steps, it is assumed that a staff of the THA/84/002 is available to conduct the selection. He should be a native of the Northeast and hence able to speak the local language, has at least technical background in construction from vocational school, and some sensitivity to social issues. The steps are:

  1. Initially he should meet with village leaders of the target villages, who then were asked to hold meetings of villagers, to inform villagers about the project requirements such as who will pay for the construction materials and whats are expected from the benefiting villagers. Since the cost of materials for construction is usually beyond the village affordibility, it is normal that the project or other government programs (see section 1.3.3) pays for it. One requirement that is effective in screening project is that villagers are expected to share the cost in some manners such as unpaid labor for construction.

  2. He then tries to find more information about the village by talking to people from other villages. Information sought are for example; how strong the leadership is, whether there has been any form of collective development by villagers, and other social information. He should visit the village from time to time to see if the requested meeting were conducted. However he should not interfere with the meetings.

The above two steps take from one to two months. After these two steps, three outcomes are possible. First, the village leaders may not be enthusiastic enough to call meeting at all, and hence there was no meeting. Second, the meetings may have occurred a few times and only a few people attending and eventually dissolved. These two outcomes indicate that the weir construction should not proceed if it is to be utilized and maintained by villagers--and hence project termination. Third, the meetings occurred and eventually more than approximately 15 families are interested in weir construction. These families represent the beneficiaries who can be depended upon for effective utilization and maintenance. This last outcome is a good sign of success--and hence the construction can proceed. This stage completes the selection of beneficiaries.

  1. In the steps described so far, it is usual that the beneficiaries also have agreed on approximate site of the weir. The project staff should ask the group to show him the agreed site. At the site, technical feasibility should be checked. Technical feasibility investigation is simple and is described in section 2 of the weir manual (Appendix C). If the site is not suitable (which is known immediately at the site), the farmer group must be told to select other site. another suitable site. This complete the process of site selection. It is strongly suggested that site be determined by the expected beneficiaries rather than some one foreign to the community no matter how much he thinks he is capable of selecting the most suitable site.

  2. The design and construction process can then proceed in the manner described in the weir manual of Appendix C.

1.3.3 Coordination with Other Units

Long term development of weirs (and other public facilities such as feeder roads) can be promoted through three national programs. These programs are:

  1. The Kor Chor Chor Program (KCC), (reference 2).
  2. The Kor Sor Chor Program (KSC), (reference 3).
  3. The People Volunteer Weir Program (PVWP), Appendix D.

The three programs should be considered as sources of funding. All three sources should be explored. In all the three programs, Tambon councils must be the initiators for the weir construction project in their respective areas--then propose it to district officer. It is normal to find that the district officer assigns this responsibility to one of his many deputies--usually the deputy for development. For KCC, the decision for funding is made in Bangkok. There is tendency though to shift the decision responsibility to province. For KSC and PVWP, the decision are made at the province.

In the past, one of the problems in the process of weir development is the lack of feedback from and participation of the users or farmers. Here the THA/84/002 project can contribute. One way the project can contribute is already outlined in the section on Selection of Beneficiaries and Sites.

According to those who are involved in creating the KSC and KCC programs, it is advisable that Tambon councils prepare five year development plan. The Tambon development plan can contain weirs, feeder roads, bridges and other facilities as long as they are for public use. The THA/84/002 project can contribute by helping the Tambon councils prepare the plans. The Local Advisory Committee can be an entry point for such assistance.

The project can also contribute by assisting in the process of project screening at the district and provincial levels by making contacts with appropriate officers. Active push at the Local Advisory Committee may be worthwhile.

Bureaucratic procedures involved in these programs are tedious and confusing. Even officers who are supposed to be responsible for it are not clear. The THA/84/002 project intervention can therefore be beneficial. To do this, a project staff is required as a facilitator. His duty is to make contact with the Tambon Councils, the deputy district officer, the provincial office, the fourth regional office of the Royal Irrigation Department (RID) in Khon Kaen, and the Accelerated Rural Development (ARD) regional office in Khon Kaen.

A desirable situation which may be hard to achieve is to have the THA/84/002 project manages all the money available for SSIF from the three national programs. The activities can then be coordinated both in time and locations and will be much more efficient than it is now. For the size of the Phu Wiang watershed area, only one senior technician can take care of all related works. To achieve this ideal situation, high level lobbying must be made.

1.3.4 Areas Stand to Benefit from Weirs Development

On the average, each weir without canals can irrigate about 400 rai. With canals the command areas can be expanded to several thousand rai. For planning purpose, areas stand to benefit from weirs are areas lying approximately within half kilometer from both sides of streams having widths between 5 and 20 meters. The benefitting areas correspond roughly to watershed classifications 4 and 5 applied to the Phu Wiang watershed area. In order to avoid conflict, weirs should not be built within the forest reserve. Exceptions are allowed only upon special permission from the Ministry of Agriculture and Cooperatives. Violation can be serious to the officers involved. The case of the governer of Chaiyapum in 1987 is a good example.)

KKU experience (reference 4) suggests that approximately 17 % of existing rainfed rice paddy land of Phu Wiang can benefit from full scale weir development.

More areas can benefit from weirs if canals are built. However canal development must be cautiously done due to many complicating factors (reference 5). There are many examples in medium scale irrigation systems where canals are available without efficient uses (reference 6).

1.3.5 Improvement of Existing Systems

Existing underutilized SSIF in Phu Wiang should be improved on case by case basis. Decision to improve any systems should be based on indication that sufficient number of farmers are willing to participate. Once this is confirmed, technical investigation can proceed. Item 1 and 2 of section 1.3.2 can be used. Only after this is done that decision to improve the systems can be made.

1.3.6 Watershed Management

Factors involved in watershed management are many, such as forest, land and water. the following discussion emphasizes only the water related issues in watershed management.

For Phu Wiang, erosion is a serious problem that need to be addressed before others. To minimize erosion, forest management, upland water harvesting and weir construction should be done. A series of weir built on streams not only provide irrigation benefit but also help retarding erosion and spreading sedimentation. While forest management and upland water harvesting may be perceived unfavorably by villagers, weirs do not (if the weirs are developed using correct approach outlined earlier. The integrated action on forest management , upland water harvesting and weir construction can be made acceptable to villagers. A series of weirs in streams however creates intersystem problems if the density of weir (number of weirs in a stream) is high. For example, farmers at upstream weirs may want to keep as much water as they can to compensate for the uncertain dry spell, and not releasing water for downstream systems. These kinds of problems involve not only technical matters but also culture, believe, tradition and other social issues. At this stage, the intricacies and interaction among different weir systems on the same watershed are not well understood. Discussion addressing such intricacies can be found in Appendix E.

As for Phu Wiang, it is believed that the density of small scale irrigation system are not yet too high but will be so in the future. At this stage it is recommended that irrigation development goes ahead in parallel to a watershed water balance study and inventory of existing SSIF. The information obtained from the studies will be useful for future use when the watershed is reaching saturation stage of water development.


2.1 Types of Fish Ponds

There are three types of fish ponds in northeast Thailand. They are;

  1. Natural Fish Ponds
  2. Fish Ponds in Paddies
  3. Commercial Fish Ponds

In natural fish ponds, water stored behind weirs, small reservoirs or natural water bodies can be used to raise fish. Usually these water bodies are by-product from the effort to raise water levels for supplementary irrigation or storage for domestic uses. In these water bodies, fish fingerling can be released for future catch. The fishes are perceived to belong to the villages that the weirs belong. Usually there is no effort by villagers to care for these fishes. Even under such conditions, fish yield can be beneficial to the community. According to investigation by BRUNS (reference 7) on 25 weirs and small reservoirs built by RID in Khon Kaen , the economic return from fish raising in this fashion in many cases can be more than those from rice paddy originally aimed for when the facilities were constructed. (However it must be noted that RID weirs are notoriously underutilized in their intended function for irrigation.--see reference 8.) Fishes from these ponds are available for catch using traditional tools. In some exceptional cases where natural conditions are favorable (large water surface area and plenty of natural foods , fish in large quantity can be caught annually. In these cases, tickets are sold (by village where the pond belongs to) to persons interested in catching the fish. The income is usually used for the benefit of the owning village. However, in cases where the existing water bodies are heavily used for irrigation, conflict can develop (references 1 and 9) between those who want to catch fish and those who want to irrigate.

Fish ponds in rice paddy are usually private. They form a part in integrated farming (i.e. paddy + fish + vegetable and trees + poultry + cattle). Farmers dig ponds manually in their paddy. Buffalo manure and rice hay are laid on to selected part of the pond bed to accelerate the natural food chain. These materials also help sealing the pond bed by providing fine organic sediment. Lime is spreaded over the pond bed to help prepareing the soil. Seepage rate is observed to reduce as the pond age increases. More details can be found from the video cassette in the Attachment. This video was shot by the Appropriate Technology Association. The association mailing address is: ATA, 143/171–172 Pinklao Patana Village, Pinklao-Nakorn Chaisri Road, Bangkoknoi, Bangkok 10700, Tel. 433–1805. The video cassette is suitable for showing to villagers as campaign media.

Commercial fish ponds are private. They require stringent water control--much more than rice paddy. A number of them already exist in Phu Wiang watershed area. From the consultant field investigation, less than 10 % of ponds produce sufficient fish for the Phu Wiang market. Most of them are for owner consumption and local (village) sale. Apparently, expansion of these ponds seem to be limited by market demand and water supply.

2.2 Suitability to Phu Wiang

Out of the three types of fish pond described earlier, the first two types should be promoted as soon as possible. The third type, commercial fish ponds, needs further study before decision can be made.

Natural fish ponds should be promoted in every location where water bodies exists (except those that are already heavily used for drinking or domestic purpose). The promotion should be in the form of provision of fish fingerlings free of charge for the first few times. Some of these water bodies may have favorable conditions for fish and hence high fish yields. Together with appropriate village organization, these exceptional cases may develop into income generating activities for the villages.

Fish ponds in paddies should be promoted because they helps farmers to reduce cost of living (fish and vegetable for home consumption), and generally is within the capability of individual farm family to invest. Formal economic analysis does not exist in writing at present, but many field results indicate favorable outcomes (private communication with CUSO and ATA). Practice of fish ponds in paddies also open up opportunity for Phu Wiang farmers to be less dependent on rice and forest. Use of hand drilled wells discussed in Section 1.2 can be beneficial to fish pond in providing supplementary water.

Commercial fish ponds should not be encouraged until it is known to be commercially feasible subject to the constraints of the Phu Wiang watershed area. It is advised that the project (UNDP TH/001/88) undertakes the study.

2.3 Natural Fish Ponds

2.3.1 Procedures for Design, Construction, Selection of Beneficiaries and Sites

The procedures follow that for diversion weir described in Sections 1.3.1 and 1.3.2. This is so because the fish ponds are by-product from construction of weirs.

2.3.2 Coordination with Other Units

Assistance in form of initial provision of fish fingerling should be sought from the Royal Fisheries Department. One Fishery Station (under the department) is located in the city of Khon Kaen. This station can be contacted for the purpose. At the district level, every district has a representative from the department. For Phu Wiang, The Kaset Amphur acts on the department behalf. As of now, this Kaset Amphur is also in the Local Advisory Committee. His contribution in providing linkage between the district and the department should be explored. One way to start is to ask for his cooperation in obtaining fish fingerling during the next meeting of the Local Advisory Committee. Details on policy, objectives and procedure of Village Fishery Program of the department (in Thai) are shown in Appendix F.

2.4 Fish Ponds in Paddies

2.4.1 Construction Procedure

These ponds can be dug either by manual labor or tractors. The procedure is similar to construction of dug pond. The construction procedure is within the capability of the villagers. Buffalow drawn bulldozer can be used. However, it must be realized that extra feed and care must be provided for the buffalows.

Design of these ponds depend on the shape of paddy area owned by the farmers. The ponds are usually square or rectangular and about one meters deep. Several designs are suggested in the video cassette attached to this report.

2.4.2 Selection of Beneficiaries and Sites

Since these ponds are located in private lands, they must be done upon consent of the land owners. The ponds are private properly and hence are family oriented (i.e. operated and maintained by the owners), just as rainwater jars--in contrast to weirs which are community oriented. Potential beneficiaries are those farm families whose paddy lands are located in the flat area of the watershed. These families should be introduced to the principle of fish pond in paddy. To do this, the video cassette can be used. Study tour is also helpful. In the study tour, the target farmers should be taken to see fish ponds in other nearby area. One area that is convenient is Ban Porn Sawan, Nong Rua district. (This is the one depicted in the video.)

For a particular paddy area, the fish pond should be dug at the lowest spot in order to trap maximum amount of water during the time of receding water.

2.4.3 Coordination with Other Units

Initial assistance in providing fish fingerling should be provided in a similar manner described for natural fish ponds (Section 2.3.2).


One problem associated with feeder roads is their tendency to increase erosion. The increase in erosion is more serious as the slope of the area increase. Therefore, for Phu Wiang, more attention should be paid to areas close to the mountains. In such areas, feeder roads are usually associated with logging activities. To slow down erosion, cooperation with logging company must be sought. Casual field observation by the consultant revealed that no effort to reduce erosion on logging roads is evident at all (as of October, 1987).

Construction of feeder roads increase erosion by the following means.

  1. Destruction of natural soil cover. This expose soil surface to erosion by rainfall and overland flow.

  2. Changing of natural drainage pattern. The presence of road obstruct natural overland and stream flows. If the water is confined to flow into too narrow passage, flow velocity and hence erosion will increase.

To reduce the destruction of natural soil cover, road must be constructed carefully and the soil surface must be shield by riprap (i.e. putting erosion resistant material such as cobbles on the surface of the soil) or vegetation (i.e. planting grass) afterward.

To minimize the change in natural drainage pattern, culverts should be used. Culvert is a large diameter pipe (.2 to 1 meter) laid underneath a road to enable water to flow under. It is better to distribute culverts along the length of the road than to concentrate them at only a few places. The more culverts the less effect on natural drainage pattern produced by the road--and hence less erosion. The use of culvert also reduce the chance of the road being washed by flood.

On flat terrain, culvert of half or one meter in diameter should be laid along every 500 meters of road length. More culverts should be laid at low spots or at locations where natural drainage channels are evident.

For feeder roads near or on mountains, culverts should be laid at shorter interval than that for flat terrain. When roads are constructed over obvious natural drainage channels, culverts of sufficient water carrying capacity must be laid. Elaborate design procedure exist (reference 10) and can be used for such purpose.

Since culverts add cost to the road, and there are many uncertain hydrological factors involved in determining suitable culverts, the process of laying culverts should be trial and error.

3.1 Construction Procedure

Practical feeder roads are of two types as follows;

  1. Seasonal road
  2. All weather road

Seasonal road are temporary road made by clearing virgin soil surface by manual or tractor. Usually, this type of road can not be used during wet season due to its slippery surface and inability to withstand heavy load. All weather roads are similar except that the road surfaces are covered with laterite. Laterite is usually brought from natural laterite pits nearby. It is normal to find that land possessing natural laterite pits are not claimed by villagers due to its uselessness to agricultural production. However this situation may change in the future. Manual labor or tractor are common for construction. It is normal and practical that feeder roads are built as improvement to existing cart tracks. New type of design by ARD using interlocking bricks is being experimented but not yet readily practical. Culverts should be laid at intervals along the roads as discussed earlier in order to reduce erosion and destruction of the road by flood.

3.2 Selection of Beneficiaries and Sites

It is recommended that feeder roads are built as improvement to existing tracks. They should never be built afresh on land without existing tracks. As such, beneficiaries and sites already exist and need no selection.

The rational behind such recommendation is because feeder roads necessarily cut across many pieces of lands owned by different owners, and that settlement is a difficult issues especially for Phu Wiang where many small land owners exist.

Other remarks for feeder roads are:

  1. When some parts of the road get stuck by right of way and land related issues, one way to work out is to allow the road to zig-zag along seams of lands owned by different owners. This distributes the burden of land sacrifice to be shared.

  2. Avoid laying road that cut right into someone's land such that too small pieces of land results. For rice paddy, area less than half a rai is too small to work conveniently with.

  3. When feeder roads are to be laid on existing paddies where farmers let water flow from paddy to paddy, care must be taken to minimize the obstruction of the flow. Culverts should be used in such cases.

  4. All land owners that the road will cut through (even with the existence of original track) must be informed. This can be done through the project's CV.

  5. It is recommended to have villagers involved in the process of feeder road development from the beginning when decision is to be made if the road is needed. The approach similar to that described for weirs (Section 1.3.2) should be used. Some form of cost sharing such as unpaid village labor for construction can be used to strengthen sense of belonging. Conflict should be left to the villagers to solve among themselves. If conflict can not be resolved, the road should not be built.

3.3 Coordination with Other Units

According to Kor Sor Chor and Kor Chor Chor programs (references 2 and 3), feeder roads are considered to be an items in rural development to be initiated by the Tambon councils. To make use of these programs, five years development plan should be developed for each Tambon by the respective Tambon council. Feeder roads can then be included into the plan together with other facilities such as weirs. The plan should then be put forward to the district officer. Discussion made with respect to weir in Section 1.3.3 also hold true for this section.


  1. NALINEE TANTUVANIT - Lessons from the KKU-NZ Weirs: An Evaluation of the Khon Kaen University-New Zealand Small Scale Water Resources Project, KKU October 1988.

  2. KHON KAEN UNIVERSITY - Study on Utilization of Weirs and Small Reservoirs in Northeast Thailand, January, 1986. Chapter 2 (in Thai)

  3. VANPEN SURARERKS - Thai Government Rural Development Programs. An Analysis and Evaluation of the Rural Job Creation Programs in Thailand 1980–1985, Department of Geography, Faculty of Social Sciences, Chiang Mai University, July 1986.

  4. SANGUAN, P. and PRAKOB, W.- Potential of Weirs and Small Reservoirs in Northeast Thailand, a research report, WREI, KKU, October 1987. (in Thai)

  5. BRYAN BRUNS - Why Don't Farmers Dig Canals?. An article in TRIMNET Newsletter and year 2nd issue July 1987, WREI, KKU.

  6. KANDA PARONAKIET - Farmer Participation in Lam Cha Muak Irrigation Project. An article in TRIMNET Newsletter 2nd year 2nd issue July 1987 WREI, KKU (in Thai)

  7. BRYAN BRUNS - Rice, Vegetables and Fish: 25 Small Small Scale Weirs and Reservoirs in Khon Kaen, a study under WREI, KKU, September, 1987.

  8. THE BUREAU OF BUDGET - Report on Evaluation of Small Irrigation Projects Under the Royal Irrigation Department. June 1985.

  9. NGAOSILP KONGKLAO - Weir Management in Kum Mum Watershed, Ubolratana District - Case Studies. WREI, KKU, December 1987 (in Thai)

  10. HENDERSON, F. M. - Open Channel Flow. Macmillan Sixth Printing, 1971. Section 7.4


ARD= Accelerated Rural Development Office
ATA= Appropriate Technology Association
CUSO= Canadian Volunteer Organization
CV= Contact Volunteer
KKU= Khon Kaen University
KCC= Kor Chor Chor Program--a National Program for Rural Development (Reference 2)
KSC= Kor Sor Chor Program or Job Creation Program--a National Program for Rural Development (Reference 3)
PVWP= People's Volunteer Weir Program (Appendix D)
SSIF= Small Scale Irrigation Facilities



This appendix describes first the appearance of the various small scale irrigation facilities (SSIF), and later the selection of the most appropriate facilities for Phu Wiang. The method of decision matrix was used in the selection. Weirs and hand drilled wells were found to be the appropriate facilities.

A.1 Available Facilities

Available small scale irrigation facilities (SSIF) are as follows; small reservoirs, weirs, deep wells, dug ponds, hand drilled wells and shallow wells. Their physical appearances and technical descriptions are described below.

Weirs and Small Reservoirs

Weir is a structure built on or adjacent to a stream to obstruct normal flow so that water level behind the weir is raised for irrigation of rice paddy field nearby. Water is stored in the stream behind the weir for a few kilometers upstream. Weirs are usually made of concrete. Other traditional weirs were made of earth or wood.

Small reservoir is similar to weir except that it has a much larger surface area of water behind it. Small reservoir takes advantages of the topography of the area, together with man made embankments, to form the storage area. Water stored behind a small reservoir is much more than that of weir.

Hand Drilled Wells and Deep Wells

Both are made by drilling holes into the ground. Hole diameters range from 5 to 15 centimeters. The depths range from 15 to 30 meters for hand drilled wells, and up to 200 meters for deep wells. Hand drilled well get its water from the shallowest confined aquifer. Deep well gets its water from confined aquifer below that of hand drilled well. (Shallow well, on the other hand, gets water from unconfined aquifer or water table aquifer.) The water from these wells must be lifted for use. In some rare cases (for example, in Munjakere and Na Chuak) where piezometric head are higher than the ground levels, the wells become springs. In typical village settings, these wells can be identified by hand pumps which are fitted on top.

Shallow Wells and Dug Ponds

Shallow well is made by digging a hole of about one meter diameter into the ground. The depth is usually less than eight meters. The diameter and depth are related to the way these wells are made--manual digging. Water is obtained from the unconfined aquifer. Water lifting is required. Manual lifting by mean of bucket and rope is typical.

Dug ponds are hydraulically similar to shallow wells. Dug pond can be though of as many shallow wells connected together. In a typical dug pond, the water surface area is about 20 × 20 square meters.

Decision Matrix

In order to find the most suitable SSIF for Phu Wiang, the following decision matrices were constructed. The first matrix, Table A.1, considers small reservoirs and weirs together. The second matrix, Table A.2, considers shallow wells, hand drilled wells, deep wells, and dug ponds. The facilities were separated into two groups as such because they share some common characteristics as shown in Table A.3.

Table A.3 Comparison of SSIF Characteristics

 Small Reservoirs and Weirs
(Table A.1)
Hand Drilled Wells, Shallow Wells, Dug Ponds, and Deep Wells
(Table A.2)
Managementby groups of farm familiesmostly by individual families and groups
Area benefitednarrow strips along streamslow land areas of the watershed
UsefulnessSupplementary irr. of rice paddy
Dry season Vegetables
Domestic uses
Domestic uses
Vegetable growing

Factors affecting suitability consideration are shown in the top rows of Tables A.1 and A.2. Numbers in brackets indicate the weights assigned to the factors. Higher values imply more importance. Scores are given as A or B or C. A is best and C is worst (A = 4, B = 3, and C = 2). Whenever numerical information is available (which is shown together with the score), the scores can be given objectively. Otherwise subjective rating were done. The weight and score were multiplied and summed to obtain total score for each facility. These total scores were than compared. The facility with maximum total score was then selected from each Table. Total sores for each facility were shown in the last columns of both Tables. Evidently, weirs and hand drilled wells were selected.
(note: Table A.1 and A.2 from LOTUS files “PWAPPA”)

Table A.1 Decision Matrix for Small Reservoirs and Weirs

Small ReservoirsB
1 to 4
A 400BCA up to 1BC69
.2 to .5
A 400AAC up to .1AA86


Table A.2 Decision Matrix for Other Small Scale Irrigation Facilities

Shallow WellsA
2 to 4
C 1 to 2ABB58
Hand Drilled WellsA
2 to 4
B 1 to 4ABA64
Deep WellsC
20 to 60
A up to 10CCC44
Dug PondsC
5 to 40
A up to 10ABC56





Duration: 2 Manmonths on parttime basis during the period from July till December 1987.

Background information:

Since 1982 the Watershed Management Division of the Royal Forest Department is implementing the integrated development project of the Phu Wiang watershed. Assistance has been provided by UNDP and FAO during the one-year planning phase in 1982, and is being provided also in the second phase-this project-since 1985.

The project aims at the conservation of the forest reserve in Phu Wiang, which covers 200, or approx. ⅔ of the total area of the watershed. Since 1982 the encroachment upon the forest lands by the local farmers has increased considerably, and in 1984 more than 3 000 ha. were used (illegally) for the cultivation of cassava.

One of the objectives of the project is to diversify the economy and create new sources of income based on the sound use of the forest, land and water resources.

It is hoped that additional income obtained in this way might prove in the long term a better alternative than growing cassava inside the forest reserve.

Among the activities specified in the project document to achieve this objective are the construction or improvement of small weirs, small irrigation systems, ponds and roads.

During the planning phase in 1982 a soil/land capability classification and irrigation potential survey was realized in the Phu Wiang project area.

Among the equipment purchased by the project in its second phase are a Bulldozer DGD 150 HP, a truck and three 4WD-pickups.

Since 1982 approximately 18 km. of existing roads have been improved and 10 km. of new roads constructed by the project, as well as five dams to create ponds for watersupply.

Several other agencies are involved in similar types of activities, like the Accelerated Rural Development Programme, and the Royal Irrigation Department, and coordination on these activities is pursued through a Local Advisory Committee chaired by the District Chief (Nai Amphoe).

Given the objectives of the project the engineering activities should be beneficial to those groups of the watershed population who are most dependent on income from cassava cropping. Hence equal attention must be given to the proper identification of the potential users of improved or newly built engineering works, as to the proper location and design of such works.

The early involvement of the villagers in the whole process of identifying needs, selection of sites, construction and maintenance of works is considered essential. It is expected that through village workshops and with the assistance of “contact villagers” this approach can be much improved.

To advise project management on the proper design and construction procedures for small scale irrigation facilities, fish ponds and feeder- road planning and construction, as well as on the appropriate way of involving the potential users, the assistance is required of a national consultant in agricultural engineering. This consultancy is defined in the project document under budget line 17–03.


17–03: National Consultant in Agricultural Engineering (THA/84/002).

A national expert on a part-time basis for a total period of two months in 1987 to advise the project management on:





Sacha Sethaputra
May 1987

After going through document you gave me including the term of reference for Agricultural Engineering), I totally agree with you on the necessity of having users involved in the whole process from identifying needs to operation and maintenance of the facilities.

Since villagers are the target people of the project, my following comments are aimed at them.

1. Seasonal Migration

From the last paragraph of page 9 of the reference*. I suspect that seasonal migration occurs - probably a little less than the northeast average. By seasonal migration. I means the annual event of northeasterners moving to Bangkok and other parts of Thailand during off-agricultural season looking for jobs. From the villagers point of view, seasonal migration not only releases the burden of day to day feeding but also generates income for the family. From the project point of view, seasonal migration partially reduces forrest encroachment. The project can help make seasonal migration of the people in the watershed area more systematic (e.g cooperate with the labor department for housemaid training, etc) and hence provide a partial control to forrest encroachment.

The concept behind this rational is that - since seasonal migration occurs anyway, why not make use of it. You can say it is one way of transferring the problems to other regions.

2. Forest Preservation Campaign

Mass media and other forms of mediums should be used. The target audiences are the villagers. The idea is to point out the long term benefit of balance living with forest in term of drough and flood prevention. School children and housewives should be the main target. The campaign topics can include birth control or other topics initiated by the audiences. Resources persons or team from university or teacher colleges can be hired cheaply to do the job. The village workshop can also serve the purpose.

* Thongmee and van Ginneken - Integrated Development of the Phu Wiang Watershed, March 1987

3. Monitoring

Feedback from villagers should be collected from time to time. This can be done by the RRA team similar to the Farming System Research Group of Khon Kaen University. The feedback will be used to adjust the project strategy as necessary (e.g to suggest a better form of campaign, to assess the effectiveness of project activities, etc).

4. Long Term Migration

This is not a suggestion, but it is something that I can not resolve. Suppose your project is so successful in diversifying the rural economy (objective number 2), how would you prevent villagers elsewhere to move in and offset the situation. This somewhat has happen as indicated indirectly in the last sentence of the first paragraph of page 9 of the reference.


Other Recommendations Made Before
the Preparation of this Report


by Sacha, October 13, 1987


Volunteers among neighbour villages should be rotated so that volunteer select from one village has a chance to work in other villages. To keep the expense on rotation to a minimum, volunteers should be assigned to village close to their native village. Bicycles may have to be provided.


There should be 3 assessments

  1. Within a few months from now. To adjust tactics and procedures used by volunteers in dealing with villagers. This can be done by hiring RA team from KKU (eg. FSR or WREI).

  2. One year after volunteers are applied. To assess the effectiveness of volunteers.

  3. Two year after volunteers are applied. To assess the efficiency of volunteers.


The supervisor must also be able to guide individual volunteers on how to tackle the problems in their assigned villages. This implies a full time experience supervisor. To have only the monthly meeting where volunteers report their monthly activities and problems is not sufficient.

by Sacha Sethaputra
as a national consultant
from September to December 1987.

1. Village Volunteer

Guidance was provided on aspects of small scale water resources development to volunteers during the monthly meetings (September 1 and October 5). The consultant's opinions on concept and administration of volunteer were made available to Pieter.

2. Requests for Weirs from Tambon Councils

Advice was given to project staff on appropriate response to the requests (note in Thai to Khun Narongchai, November 10). Cost estimate and weir design for Ban Po were done and given to Pieter (memo dated November 19).

3. Comment on a Report

Comment was made on a report titled “Cost-Benefit Analysis of Forest Plantations: An Approach for Phu Wiang, Khon Kaen Province, Northeastern Thailand” in response to Pieter's request.

4. Meeting of the Local Advisory Committee

The consultant observed such a meeting on October 15–16 in Phu Wiang.

5. Meetings with Project Evaluators

5.1 With a staff member of the Office of Auditing (Khun Yupin) on October 16 at the project office.

5.2 With the team from UNDP (Dr. Cheng and team) on November 9 at the project office.

6. Field Assessment

Several man-days of field trip were made by the consultant and his assistant in the watershed area to conduct reconnaissance surveys of the followings. The consultant does not intend to write a report out of these but will do so if asked.

6.1 Water Requirement of the 8 Target Villages. This was conducted to assess the village water requirements for drinking, domestic and agricultural uses. The survey also reveal the strength of development leadership of the villages.

6.2 Potential of Shallow Ground Water. This was conduct to assess the feasibility of utilizing shallow ground water for agricultural uses such as dry season vegetable growing and fish pond.

6.3 Present Situation of Fish Pond in the Area. This was conducted to assess the number and size of existing fish ponds in the 8 target villages.

6.4 Soil Sampling for Brick Making. Soil samples were collected and analyzed to see if they are suitable for local brick making.

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