Project Background
The Government of the Union of Myanmar has requested a loan from the OPEC Fund for International Development (OFID) to assist in financing the completion of two separate irrigation projects – Thonze and Kabaung. The irrigation schemes were selected by the Government from a longer list. In these two schemes, the headwork in the project areas has been recently completed but there is a need to complete the development of the command areas.

Project Objectives
The project objective would be to complete construction of two irrigation schemes. The project would also develop and strengthen the water users associations in the irrigation system to improve the efficiency of the water distribution and raise the incomes and livelihoods of rural people in a sustainable manner.

Project Description
The project has three components:

Component (1): Construction of Irrigation and Drainage System - The project would complete the Thonze and Kabaung irrigation and drainage schemes through construction of main, distributary and minor irrigation canals and drainage canal distribution networks, and associated water control structures. The project would cover a net serviceable command area of 38,700 ha benefiting 14,000 small holder farm families (80,000 persons). Since the dams and headwork are already completed in both schemes, the irrigation can be realized immediately after completion of distribution networks.

Component (2): On Farm Development works, WUA Formation and Capacity Building - The project would construct 1,930 water courses (about 1,280 km) and on-farm drains by direct participation of beneficiary farmers using Participatory Irrigation Management (PIM) principle. The component also aims at maximising and sustaining the project’s benefits by strengthening farmers’ knowledge on-farm irrigation development and water management. This will be done by a series of outreach training sessions targeting farmer representatives in the Project command area. Field staff from relevant Government O&M agencies will be trained as trainers, thus their technical knowledge base and skills to interact with farmers would be further strengthened.

Component (3): Project Engineering, Management, Monitoring and Evaluation -The project would finance detail engineering survey and investigation, detailed design and construction drawings, quality control including environment impact monitoring and assessment and related incremental expenses.

Executing Agency
The Irrigation Department (ID) under the Ministry of Agriculture and Irrigation (MOAI) will be the executing agency, responsible for the project implementation and management under a Project Manager with the level of Deputy Director General. Overall coordination of the project activities would be through a Project Steering Committee, chaired by the Deputy Minister of Ministry of Agriculture and Irrigation (MOAI) and Secretary as Director General of Irrigation Department (ID) ( under the notification No. 75/2007 dated 21.Dec.2007 of MOAI ). Project monitoring would be the responsibility of the Department of Agricultural Planning (DGDAP) and project evaluation would be the responsibility of the Settlement and Land Records Department (SLRD) of MOAI.

Project Justifications
The project has been prepared taking full account of technical feasibility, economic viability, positive environmental and social impacts and sustainability.

Environmental Assessment
The environmental impacts resulting intensification of agriculture have been assessed and mitigation measures proposed would ensure that negative impacts of irrigation are successfully and effectively mitigated. In effect, the project would generate positive environmental benefits in terms of groundwater recharge, and more effective water management through better on-farm water management practices; controlling water logging and flooding through investment in surface drainage distribution systems and on-farm drainage. In addition the project through the drainage investment would reduce Malaria and other water-borne diseases.

Map 1 - Location of the Proposed Irrigation Schemes

Information on completed Irrigation Head works of both Projects

Thonze Dam Project
Thonze Dam Project is situated in Tharyarwady Township, Bago Division. The proposed dam site is located about 7.3 km U/S of Hlelangu village (Map ref: 85 O/14- Grid F - 314530). The catchment area at proposed dam site is about 228.4 Km2. The Thonze river bed level at the dam site is 29.2 meter above mean sea level (m.s.l) and the ground level of the highest abutment hilly part surrounding the dam axis is about 83 m above m.s.l.

Salient Features of Thonze Dam and Appurtenant Structures

The construction of Dam and appurtenant structures, such as outlet works, service and emergency spillways including the diversion weir downstream of the dam have been completed since FY2004-2005. Some salient features of the completed dam and appurtenant structures are shown below.

Kabaung Dam Project
Kabaung Dam Project is situated in Oaktwin Township of Taungoo District, Bago Division. The proposed dam site is located about 23 km south west of Oaktwin town (Map ref: 94 B/1- Grid 655920). The catchment area at proposed dam site is about 1087 Km2. The Kabaung river bed level at the dam site is 69.2 meter above mean sea level (m.s.l) and the ground level of the highest abutment hilly part surrounding

Salient Features of Kabaung Dam and Appurtenant Structures

The construction of Dam and appurtenant structures, such as saddle dam, outlet works, service spillway have been completed FY2006-2007.

The diversion weir downstream of the dam is still under construction and planned to be completed in FY2007-08. Some salient features of the completed dam and appurtenant structures are shown below.

CONSTRUCTION OF THONZE AND KABAUNG IRRIGATION AND DRAINAGE SCHEMES
THE PROJECT AREA

Location
The proposed project comprises of two individual irrigation and drainage schemes namely, Thonze Irrigation and Drainage (I&D) Scheme and Kabaung Irrigation and Drainage Scheme, which would benefit two different regions of Myanmar (Map 1). Thonze I&D and Kabaung I&D schemes are on either side of Bago Yoma (Bago Range), Thonze on the west side and Kabaung on the east side. Although an annual average precipitation in both scheme areas are more than a 1000 mm per year, they suffers from frequent seasonal water deficits; distinctive dry season months with no rainfall, prolong dry spells and floods as a result of substantial temporal and spatial variability of the rainfall. The irrigated and drainage agriculture in general can be defined as artificial supply of water to cultivated crops in the form of irrigation in areas where rainfall is insufficient and extraction of surplus water from cultivated areas, drainage, in case of cultivated areas with abundant moisture. Consequently, development and management of water resources, primarily surface water, remain a high priority of the government to date.

The Thonze I&D Scheme (Figure 1) lie within Thayarwadi Township in Bago Division which is about 195 km from Yangon. The Kabaung I&D Scheme (Figure 2) lie within Oaktwin Township of Taungoo District in Bago Division which is about 280 km north of Yangon. Even though the service areas of both lie in areas having good rainfall of 1,200 to 2,000 mm, these rainfalls usually concentrate in about 4 months between the periods of May to October that dry season crops are impossible unless the area is serviced by irrigation. Moreover, it is also common to have dry lull periods of up to 7 or more days in the wet season periods in central Myanmar that even wet season crops often suffer significant yield reductions without supplementary irrigation. In the dry season months of November to April, raising crop is practically impossible at all. In addition, a large area is flooded due to the poor drainage systems, which prevent early transplanting of paddy crop. Lack of irrigation distribution systems also makes it very difficult to grow a second crop, particularly, summer paddy in the dry season.

Climate
The insufficiency or abundance of moisture for all part of the two project areas can best be judged by a parameter called “Moisture Availability Index – MAI”, which is the ratio of dependable precipitation to crop Evapo-transpiration (ETO). Since the dependable precipitation in general is less than average precipitation of an area, for the general visualization of the “wetness” or “dryness” for an area, it can be determined by using about 80% of average rainfall as the dependable rainfall. From the MAI for both areas it can be seen that practically Thonze area as well as Kabaung area practically cannot raise successful crops due to moisture stress in 6 to 7 months in a year (November to May) unless the crops are irrigated; whereas in the case of rainy season appropriate drainage may be a necessity especially in July-August months. Thus the irrigation and drainage projects are formulated to carryover the wetness of rainy season to use in the subsequent dry season by means of re-regulation or seasonal storage dams.
 

Topography, Soils and Land Use
The Thonze irrigation and drainage area lies on both sides of Thonze River in Tharyarwaddy District. The service area inclines generally from East to West and normally flat from North to South. The elevation of the project area varies from 30.5 m above mean sea level (amsl) at the east to about 10 m amsl at the western part with a gentle slope of 1 to 1000. The area is covered by old and new alluvial deposits with a sufficient depth of uniform soil. The soil in the project area can generally be classified into five soil groups (by FAO classification) as: Cambisols, Gleysols, Humid Gleysol, Fluvic Cambisols and Fluvisols and Lateritic Soil, as observed from the upper piedmont plain towards lower piedmont to active flood plain. The majority belongs to Cambisols to Gleysols. Out of the total gross soil survey area of 36,400 ha in the project area, only 21,700 ha net are cultivable and are being utilized for agricultural production. All cultivable land are sown with paddy in the wet season followed mainly by black gram, groundnut, sesame and sunflower on some areas (7,300 ha) in early dry season using residual moistures. The present cropping patter is about 126-130%.

The Kabaung Irrigation and Drainage Scheme lies on both sides of Kabaung River in Oaktwin and Taungoo Townships of Taungoo District. The service area lies in alluvial plain and about 60 percent of it is composed of nutritious Fluvisols, Gleysols, Cambisols and Fluvic and the Ferric and Luvisol. Luvisols are common on the left bank of the river and Cambisols are common on the right bank where the current project area will be developed. The soil is low in the acidity and as such it is favourable for paddy cultivation in both monsoon and dry season. The infiltration rate of the soil in the project area is mostly slow (less than 1 cm/hr). Out of the total gross areas of 50,000 ha available for irrigation on both banks of the river, about 9,000 ha are unsuitable for irrigated agriculture leaving 41,000 ha as developable land. Of that over 67% of the land is suitable for paddy, while about 3,200 ha are not suitable for paddy irrigation. All cultivable land at present is sown with mostly paddy in rainy season followed by black gram green gram and other short period upland crops. About 6-7 percent of the present land is sown under sugarcane. The present cropping intensity is about 135%.