Report

Regional Surface Water Availability during Dry and Monsoon Seasons in

Md. Zahurul Islam*

Summary The present study briefly describes available streamflow

generated within Bangladesh, inflows from the Brahmaputra--Padma (main river system), cross-boundary inflows from India, static water resources, instream storage potential, streamflow salinity, and water demands in different sectors like domestic and industrial uses, navigation, salinity control, fisheries, agricultural water use, etc. It reveals that Bangla desh has a two-fold water problem-too much in the monsoon season, causing devastating floods and too little in the dry season, causing severe drought. As a result, saline water intrusion occurs in the dry season from the Bay of and streamflow salinity increases up to 10,000ƒÊmho/cm, especially in the Southwest (Passur River) and South Central (Baleswar River) Regions. In Bangladesh water demand for different purposes is increasing day by day. Due to the scarcity of water supply in the dry season, normal life for the people and development activities in the country are hindered. For the sake of the survival of humans and animals and a safe environment, necessary water supply should be ensured in both the monsoon and dry seasons through properly planned Barrage Projects.

I. Introduction Readily available water for the population used to be regarded as an inexhaustible gift of nature by many people in Bangladesh. However, rapid population growth and the consequent increase in demand for water in every sphere of the national life and economy are seriously straining the water resources available in Bangla desh. At the same time, the gradually decreasing supply of surface water in the lean season of the year is making the situation ever more difficult (Khan , 1987; USAID, 1983). Bangladesh is a land of rivers. All the rainfall runoffs and snow melts of the south and southeast slopes of the Himalayan Mountains, including the local rainfall, pass over Bangladesh through big and small rivers and fall into the . During the monsoon season (June to September), heavy rains associated

Resarch Fellow, The Japan Societyfor the Promotion of ScienceResearch Section for River Disaster, Disaster Prevention Research Institure, Kyoto University, Kyoto-611, Japan. Assistant Professor, Institute of Flood Control and Drainage Research, Bangladesh University of Engineering and Technology,Dhaka-100, Bangladesh (Manuscript Received May 23, 1991, Accepted May 27, 1993)

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Figure 1 Yearly average flood inundation and damage of agricul- tural production with melts reach the level of 108,000 m3/s in August, causing devastating floods almost every year that affect 20-35% of lands under cultivation, resulting in untimely damage to agricultural crops (as shown in Figure 1) and adversely affecting food production. Hence, the country suffers food shortages every year, especially during and after flood season (MPO, 1987). But the situation changes entirely during the dry winter season (November to May), when there is little rain in the Brahmaputra-Ganges-Meghna basins and river flow declines to a minimum of about 6,930 m3/s in February. So Bangladesh has a two-fold water problem— too much and too little water. These two extreme natural conditions compelled the country to make plans for flood control, flood protection and judicious allocation of scarce water resources in the dry season for different uses in agriculture, fisheries, navigation, households, and industry, and for ecological equilibrium. The water availability situation in Bangladesh is unique in its characteristics and nature (Khan, 1987; MPO, 1984). The different regions of the country are geographically separated by the major rivers: the Ganges, the Brama- putra, the Meghna, and the Padma (representing the combined streamflow of the Ganges and the Brahmaputra), each having distinct hydrological features (Khan, 1987; MPO, 1984; MPO, 1985). In the past the country made a few plans, mostly to solve flooding problems, because scarcity of water was not pronounced at that time. Reduction of dry

Irrigation Engineering and Rural Planning No. 26, 1994 REGIONAL SURFACE WATER AVAILABILITY 33 season flow of the international rivers due to upstream use and diversion and requirements for increased foodgrains supply for the growing population has made the nation think afresh. In this paper available monthly streamflow in the main river system, static water resources, instream storage potential, streamflow salinity and water demands for different sectors are discussed to identify the problems due to too much and too little surface water during the monsoon and dry seasons in the country, and some recommendations for overcoming the situation are made. For the study a literature review was conducted and data and necessary information were collected from the Bangladesh Water Development Board (BWDB), Master Plan Organization (MPO)1), Bangladesh Agricultural Development Corporation (BADC), Flood Plan Coordination Organization (FPCO) and other local consulting firms in Bangladesh.

II. Surface Water Availability and Salinity 1. Available Streamflow Available streamflow in a region is the outflow from the region. Streamflow is the dominant component of water resources in Bangladesh. Each day, on the average, approximate 3,440 million m3 of streamflow are discharged into the Bay of Bengal. This figure is about 3.9 times the average daily rainfall over Bangla- desh (MPO, 1985; MPO, 1987). In this study, the availability of surface water resources has been assessed in terms of monthly streamflow, dry season static water (or standing water), and instream storage potential. The streamflows are expressed in terms of mean monthly (50% dependable) and five-year one-month low flow (80% dependable) rates. They are further divided into four components: 1. Cross-boundary inflows to regions directly from India; 2. Inflows from the Brahmaputra-Ganges-Padma-Meghna rivers (Main river system) to regions; 3. Streamflow generated within regions; 4. Outflow from regions. Total available monthly streamflow in the entire country, which is total outflow to the Bay of Bengal, varies from 108,000m3/s in August to 6,930m3/s in February under 1983 water use conditions. During a five-year low-flow condi- tion, the available streamflow in the entire country varies from about 93,700m3/s in August to about 5,620m3/s in February. Total inflow to Bangladesh from India is approximately 90% of the total available streamflow in the country. The main river system and different regions of Bangladesh are shown in Figure 2 . 1) Master Plan Organization (MPO) was founded in 1984 under the Ministry of Irrigation, Water Development and Flood Control, Government of the People's Republic of Bangladesh, to evaluate the existing water resources , make water resources policy and formulate water resources planning to meet the future water demands for domestic and industrial uses, navigation, fisheries, salinity control , agriculture, etc. MPO was renamed Water Resources Planning Organization (WARPO) in 1991.

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Figure 2 Main river systems and regions of Bangladesh

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Irrigation Engineering and Rural Planning No. 26, 1994 36 Md. Z. ISLAM

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Available monthly streamflow2) and regional surface water availability for the month of March in five different regions and the main river system are summar- ized in Table 1. Figure 3 schematically shows streamflow distribution in Bangladesh for the months of March and August (approximate 1983 water use condition). It is important to mention here that the highest and the lowest streamflow months are not same for all the regions. It is seen from Table 1 that March is the driest month in the Southeast, Southcentral, and Southwest regions, while the driest month is February in the Northeast region. This difference is due to the topographical locations of the southern regions in the lower reaches (down- stream) of the main river system of the country (Figure 2). So, when monthly streamflow is reduced to its minimum quantity of 100m3/s in the Northeast region (upstream), in February, the Southeast, Southcentral and Southwest regions have streamflow of 426m3/s, 1,150m3/s, and 267m3/s, respectively. In those regions, streamflow is reduced to 378 m3/s, 1,120 m3/s, and 190 m3/s respectively in the month of March, the driest month in these regions. It is also evident from Table 1 that the highest streamflow months are also not the same for all regions. The highest streamflow is observed in the month of August for the Northwest, Southcentral, and Southwest regions, and in July for the Nor- theast and Southeast regions. 2. Streamflow in the Main River System Approximately 85% of the total dry season streamflow in Bangladesh is in the main river system. The primary surface water development potential in Bangla- desh is, therefore, in the development of streamflows in the Brahmaputra-Ganges- Padma-Meghna Rivers. It is important to note here that the natural flows of the Ganges into Bangla- desh have been considerably modified by abstraction across the border in India, in particular at the Farakka Barrage, which is located at Farakka in West Bengal, India (Figure 2), on the Ganges only 18km upstream from the border with Bangladesh. Subsequent to the construction of the Farakka Barrage, India has been in a position to divert a substantial part of the low flow of the Ganges, and did so soon after commission of the Barrage in 1975 and the associated link canal to the Hoogly River, which is designed to divert up to 1,130m3/s (T. A. Khan, 1987). As a result of water diversion at the Farakka Barrage, Bangladesh, the country downstream of the Ganges is being deprived of normal water flow: a decrease in the dry season streamflow in the main river system causes drought, and increased streamflow during the monsoon causes devastating floods in the country. Mean monthly discharge hydrographs for the Brahmaputra and the Padma (representing the combined streamflow of the Ganges and the Brahmaputra) for pre-Farakka and post-Farakka diversion are presented in Figure 4. It is seen 2) Available monthly streamflow in a catchment or a region is the outflow from the catchment or region in a month.

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Figure 4 Long-term mean monthly discharge hydrographs for Ganges, Brahmaputra and Padma Rivers Source: MPO 1987 (Ref. 3)

from Figure 4 that mean monthly available streamflow in the at Baruria varies from about 6,400m3/s in February to about 73,100m3/s in August for the pre-Farakka period; it decreases to about 6,110m3/s in February (dry season) and increases to about 76,200m3/s in August (monsoon season), respec- tively, during the post-Farakka period. Analogical streamflows were also observed in the Ganges River at Hardinge Bridge during the pre-Farakka and post Farakka periods. Mean monthly available streamflows in the Ganges River at Hardinge Bridge during the pre-Farakka period vary from about 3,500 m3/s in February to 36,800m3/s in August; they decrease to about 1,370 m3/s in February (dry season) and increase to about 40,800 m3/s in August (monsoon season) during the post-Farakka period, causing severe drought in the dry season and devastating flood in the monsoon (MPO, 1987). During a five-year drought, the streamflow in the Padma River varies from about 5,130m3/s in February to about 67,600 m3/s in August. The best measure of drought in Bangladesh is probably the low flows in the main river system. About 90% of the country's five-year one-month low flow is found in the Brahmaputra-Ganges-Padma River during a five-year drought event. This implies that Bangladesh's water supply depends heavily on streamflow from India during drought periods. Low flow in the Padma River, representing the com bined flow of the Ganges and , is dominated by the Brahmapu tra flow, which contributes more than 65% of the low flow in the Padma River

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during the January-April period. Though the low flow analysis in the Ganges River for the post-Farakka period was based on only seven years (1975-82) of data, the analysis clearly indicates a drastic reduction of flow during January- April. In the month of March, the reduction was more than 50%. Mean daily low flows of record in the Brahmaputra at Bahadurabad, the Ganges at Hardinge Bridge, and the Padma at Baruria are 2,860, 657, and 4,250m3/s, respectively. Both the daily and monthly low flows of record in the Ganges and the Padma river occurred after the commissioning of the Farakka Barrage in April 1975. It is remarkable to note here that the reduction of dry season Ganges flow since 1975 has lowered the ground water table by 0.5 to 2 meters from the normal limits along both the banks of the rivers Ganges, Mohananda and Gorai- Madhumati. The salinity limit in the southwestern region penetrated 100 miles further inland and reached as far as Kamarkhali. The navigability of the major water routes in the Ganges and Gorai-Modhumati was reduced significantly. In the Sundarbans3), the largest mangrove forest of Bangladesh, the reduction in upland fresh water discharges has created a critical situation and is threatening the delicate ecosystem of the region. The production of fish in the Gangetic area has also fallen sharply. The reduction of flows of the other smaller rivers is having adverse effects of varying magnitudes on the agricultural practices and water supply situations in the 'areas dependent on the waters of these rivers during the dry seasons, resulting in converting the Northwest and Southwest regions into semideserts. 3. Static Water Resources In the present study, available depths of static water after 1983 water uses were estimated on a regional basis using available water use data (especially irrigation water use by traditional means), judgement gained through field observations, and the relative magnitude of static water surface area in each region. The estimated static water depth is 0.5 m for the Northwest, Northeast, Southcentral, and Southwest Regions. Zero extraction was estimated for the Southeast Region. Available static water volume after 1983 water uses was estimated to be about 167, 374, 0, 9, and 62 million cubic meters for the Northwest , Northeast, Southeast, Southcentral and Southwest regions, respectively (MPO, 1987). The above static water volumes, although small, are highly valuable surface water resources for the driest months, during which water use is much greater than the streamflow generated within individual regions. The regional surface water uses exceed the locally generated streamflow by 5.6m3/s (February), 255 m3/s (February), 49m3/s (March), 8m3/s (March), and 16m3/s (March) for the 3) Sundarbans, which means 'the beautiful forest', lies in the southwestern region of Bangladesh, in the district of greater . It is a virgin forest which until recently owed nothing to human endeavor, and yet nature has laid it out with as much care as a planned pleasure ground. The Sundarbans is a cluster of islands with an approximate area of 3600 sq. km, forming the country's largest block of littoral forests. Its beauty lies in its unique natural surroundings. Thousands of meandering streams, creeks, rivers, and estuaries have enhanced its charm .

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Table 2 Instream storage potential and surface areas during the dry season

Northwest, Northeast, Southeast, Southcentral, and Southwest regions, respectively.

4. Instream Storage Potential The instream surface areas and instream storage potential are presented in Table 2 for individual catchments and planning areas. As shown in the table, the instream surface areas for the rivers and Khals having widths less than or equal to 100m are about 103, 275, 57, and 68 km2 for the Northwest, Northeast, Southeast, and Southcentral /Southwest regions, respectively, while the instream surface areas for the rivers, Khals, Baors, and Haors4) having widths less than or equal to 50 m are about 3.9, 69.0, 5.9, and 7.8 km2, respectively (MPO, 1987). The Northeast Region contains about 50 and 80% of the instream surface area of the country for the rivers having widths less than or equal to 100 m and for the 4) Khals means canals in Bangladesh. During the dry season, water is exploited from water bodies of topographical depressions and is used for various purposes. These water bodies are locally called , Baors, and . They are generally con- nected with rivers and khals during the monsoon period. As flood recede, they become disconnected from the streams and form isolated water bodies.

Irrigation Engineering and Rural Planning No. 26, 1994 REGIONAL SURFACE WATER AVAILABILITY 41 rivers, Khals, Baors, and Haors having widths less than or equal to 50 meters respectively (MPO, 1987). For the rivers of the entire range of widths, the Southwest/Southcentral Region contains about 60% of the instream surface area of the country. As shown in Table 2, total instream storage potential of the country is 65 m3/s (or about 503 million m3) for the rivers having widths less than or equal to 100 meters, while this value is 11 m3/s (or 86.6 million m3) for the rivers, Khals, Haors, and Baors having widths less than or equal to 50 m and 662 m3/s (or 5150 million m3) for the rivers and Khals having the entire range of widths (MPO, 1987). Instream storage potential for the Northwest, Northeast, Southeast, and Southw- est/Southcentral regions are 103, 275, 57, and 68 million m3 for the rivers and Khals having widths less than or equal to 100 m and 3.9, 69.0, 5.9 and 7.8 million m3 for the rivers, Khals, Baors, and Haors having widths less than or equal to 50 m. 5. Streamflow Salinity Streamflow salinity reaches more than 2000 ,umho/cm in about 10% of the Southeast region (about 3170 km2), 27% of the Southcentral region (about 3950 km2), and about 48% of the Southwest region (about 12500 km2), of which approximately 1390 km2, 1550 km2, and 2260 km2 are within the polders of the Coastal Embankment Project in the Southeast, Southcentral, and Southwest regions, respectively (MPO, 1987). Table 3 shows the existing salinity levels for eight selected locations in the Southeast, Southwest, and Southcentral regions for the dry season months of February, March, April, and May. As shown in the table, the existing salinity levels in the month of the highest salinity, April, are 180, 1250, 2,400, and 9,010 Amho/cm at Chandpur (Lower Meghna River), Bar- guna (Biskhali River), Ilsaghat (Lower Meghna River), and Khulna (), respectively (MPO, 1986). Seasonal variations of salinity during the period January through April at Khulna (Rupsa-Pussur River) and at Ilsaghat (Lower Meghna River) are shown in

Table 3 Streamflow salinity levels for selected locations (November 1975 through June 1983)

Source: Master Plan Organization: Surface Water Availability, Technical Report No. 10, pp. 7.11 (1987)

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Figures 5 and 6 (MPO, 1986). With the decrease of Gorai flows, average salinity at Khulna starts increasing. During spring tides there is a very large

Figure 5 Seasonal variation of salinity, Rupsa-Passur River at Khulna, January-June, 1980 Source: MPO, 1986 (Ref. 9)

Figure 6 Seasonal variation of salinity, Ilsaghat, lower Meghna River, January-May, 1979 Source: MPO, 1986 (Ref. 9)

Irrigation Engineering and Rural Planning No. 26, 1994 REGIONALSURFACE WATER AVAILABILITY 43 increase in salinity. Stronger spring tides push more saline water into the Rupsa-Passur River, but during the next neap tide, the salinity is not totally flushed out. There is a successive buildup of salinity with each tidal cycle until the Gorai flow increases substantially about the middle of May. At Ilsaghat the situation is different. Between spring tide fluctuations, salinity drops to an average level which is almost constant throughout the season. High fresh water flow in the Lower Meghna River flushes the salinity completely during neap tides.

III. Water Demands Domestic Water Demand: The growth in domestic water demand is derived from three factors (MPO, 1985): (1) population growth; (2) an increase in the fraction of rural population served by tubewells, from 47% in 1985 to 87% in 2005, and in the fraction of urban population served by piped supply, from 31% in 1985 to 68% in 2005; (3) an increase in per-capita demand as water becomes more easily available. Projections of domestic water demand, including piped water provided to commercial and industrial users with population growth, are given in Figure 7. It is necessary to mention here that the average annual population growth rates from 1985 to 2005 were taken as 2.8, as per the population census year 1981 (MPO, 1986). Domestic water demand will increase from 94.7 Mm3/month in 1985 to 335.0 Mm3/month (both ground and surface water) in 2005, i.e. at an average annual growth rate of 6.5%. The demand will be satisfied largely by ground- water. The Northeast region has the highest share in total demand, and this share will increase from 38% in 1985 to 50% in 2005. The National Water Plane) provides for future domestic water needs by reserving a quantity sufficient to meet the projected domestic demands in the year 2005. Industrial Water Use: Projections of industrial water demand with Projections of industrial water demand with population growth (MPO, 1986) are presented in Figure 7. They are based on an increase of 10% per annum. Industrial water demand would increase from 24.2 Mm3/month in 1965 to 163.3 Mm3/month in 2005. Most of this water comes from deep tubewells, with only a few industries using surface water. Apart from the proposed Brahmaputra and Ganges barrages, water use for hydropower is mainly situated in the Chittagong Hill Tracts. The National Water Plan reserves sufficient water for industrial use to meet the estimated needs in the year 2005. As a side effect of industrial growth, 5) The National Water Plan (NWP) is formulated by the Master Plan Organization (MPO). The NWP consists of a set of water development policies whose goal is to maximize benefits from water resources development while attempting to provide for the water needs in all sectors (domestic and industrial users, navigation, salinity control and environment management, etc.), all within the limits of available water resources in Bangladesh.

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pollution of surface water might become a serious problem. The industrial sources with significant environmental impact are situated in Khulna, Chitta-

gong, and Dhaka.

Navigation:

There are nearly 8,000 km of navigable waterways of different categories in the

country. Inland navigation contributes a major share in the handling of goods

and passengers in Bangladesh. The required draft for different vessels and

country boats varies from 1 to 3.5 meters. During the dry season, especially in

the months of February and March, the navigable waters shrink by more than

50% (Khan, 1987).

Flood Control Drainage Irrigation Projects led by the Government and the local

administration interfere with navigation between the inside and the outside of the

polder. Therefore, the design of projects might provide for shiplocks or for boat or cargo transfer facilities. On the other hand, such projects often improve

transport on land by embankment and flood control and drainage. Water trans-

port may also be improved during the dry season, as water levels then are stable for a longer time.

Control of Salinity:

Intrusion of saline water is a problem for most of the Southwest and Southcentral

regions and for some planning areas in the Southeast. The increase in salinity is

especially critical in the months of February and March, when the streamflow is

at its lowest. If the electrical conductivity of water (ECw) rises above 700ƒÊmho/

cm, water becomes unsuitable for drinking purposes. If the ECw of irrigation

water rises above 2000 ktmho/cm, paddy yields might decline (MPO, 1986),

although some other crops including wheat can withstand a higher level of

salinity without significant yield reduction. For the purpose of the National

Water Plan the objective was to maintain EC,,, at Ilsaghat below 2000 ,umho/cm.

The salinity limit in the southern region of Bangladesh is checked and maintained by the combined flows of the Ganges, Brahmaputra, and Meghna. Any reduction in the flows of these rivers allows salinity to escalate and penetrate deep inland.

Primarily, studies and estimates indicate that a combined flow of 2,582 m3/s is required to meet the demands on the lower Meghna channel for salinity control.

Fisheries Water Demand:

Particular attention should be paid to the impact of water resource allocation on fisheries and to the formulation and implementation of policies for their develop- ment. However, about 40% of the available water from the regional rivers of the

Northwest, Northeast, and Southeast regions under 1983 water use condition has been estimated for fishery and irrigation.

Agriculture Water Demand:

Agriculture is the major user of water in the country. Area irrigated under

Irrigation Engineering and Rural Planning No. 26, 1994 46 Md. Z. ISLAM different crops in 1984-85 was only 2.07 million ha out of a total cropped area of 13.15 million ha (Bangladesh Bureau of Statistics, 1986). Under the present conditions, only 15.74% of the cropped area has been brought under irrigation. During the dry season, large areas remain often fallow or under low-yielding crops due to lack of water. Water for irrigation has mainly been supplied by surface and ground water. The country is yet to begin large and modern surface water irrigation projects. About 60% of the available water from the regional rivers of the Northwest, Northeast, and Southeast regions under 1983 water use conditions has been estimated for agriculture (MPO, 1987). As such, a maximum amount of 2,100 m3/sec may be utilized for agriculture from the main river system, upstream of Baruria by diversion from the Ganges and Brahmaputra Barrages in the driest months.

IV. Conclusions

On the basis of the above discussion, the following conclusions can be drawn and recommendations made: 1. Streamflow in Bangladesh depends heavily on inflows originating outside the country. Streamflow generated within Bangladesh (local streamflow) is rela- tively small as over 90% consists of cross-boundary inflows from India. On the other hand, about 90% of the country's five-year one-month low flow is found in the Brahmaputra-Ganges-Padma River during a five-year drought event. This implies that Bangladesh's water supply depends heavily on streamflow from India during drought periods. 2. Streamf low generated within Bangladesh, cross-boundary inflows from India, and inflows in the Brahmaputra-Ganges-Padma-Meghna (Main River System) are the highest during the monsoon and the lowest during the dry season. On the other hand, diversion of streamflow at the Farakka Barrage on the Ganges in India plays a vital role, resulting in an increase in streamflow during the monsoon and a decrease in streamflow during the dry season in the main river system of Bangladesh. 3. Decrease in streamflow in the main river system during the dry season causes saline water intrusion into Bangladesh from the Bay of Bengal. As a result, streamflow salinity during the dry season in the months of February, March, April, and May increases to a level greater than 2,000 Amho/cm. The highest salinity levels are recorded at more than 10,000 pmho/cm in the Southwest region (Passur River) and 2,500 iumho/cm in the Southcentral region (Baleswar River); this highly salinity has an adverse effect on agricultural practice, water resources, environment, ecosystem, etc., in the regions. 4. Water demands for domestic and industrial use, navigation, fisheries, salinity control, agriculture. and other uses are increasing day by day. On the other hand, water supply and availability and water flow in the main river system in the dry season are decreasing at the same time. The scarcity of water in the dry IrrigationEngineering and Rural Planning No.26, 1994 REGIONALSURFACE WATER AVAILABILITY 47 season hinders normal life for the people and development activities. Consider- ing all of these factors, it is obvious that future high water demand and low water availability will make the situation ever more difficult in the water resources sector of the coutry. The nation should think ahead about future water resour- ces planning in order to overcome this difficult situation. 5. As a result of reduction of streamflow in the dry season, the groundwater table has fallen from the normal limit, and navigability in the country has reduced significantly. In the Sundarbans, the largest mangrove forest of Bangladesh, reduction of the upland fresh water discharges has created a critical situation and is threatening the delicate ecosystem of the region. The production of fish and agricultural crops has also fallen sharply. The Northwest and Southwest regions of the country are being transformed into semidesert and desert environ- ments. So necessary water flow in the main river system should be ensured in the monsoon and dry season to avoid flooding and drought; for this purpose Barrage Projects are recommended along with proper planning.

References 1) Khan, T. A.: The Water Resources Situation in Bangladesh: Water Resources Policy for Asia, Proceedings of the Regional Symposium on Water Resources Policy in Agro- Economic Development held at Dhaka, A. A. Balkema/Rotterdam/Boston, pp. 149-150, 158-161 (1987) 2) USAID: An assessment of the Agricultural sector in Bangladesh, Dhaka, pp. 57-59 (1983) 3) Master Plan Organisation (MPO):Surface Water Availability, Technical Report No. 10, National Water Plan Project, Ministry of Irrigation, Water Development and Flood Control, Govt. of Bangladesh, Dhaka, pp. 3.1-7.14 (1987) 4) Khan, H. R.: Water Resources Development in Bangladesh-Problems and Prospects: Water Resources Policy for Asia, Proceedings of the Regional Symposium on Water Resources Policy in Agro-Economic Development held at Dhaka , A. A. Balkema/ Rotterdam/Boston, pp. 165-181(1987) 5) MPO: Surface Water Availability, Draft Final Report, Vol. II, National Water Plan Project, Ministry of Irrigation, Water Development and Flood Control, Govt. of Bangla- desh, Dhaka, pp. 4.5-4.11 (1984) 6) MPO: Surface Water Availability, Third Interim Report, National Water Plan Project , Ministry of Irrigation, Water Development and Flood Control, Govt. of Bangladesh , Dhaka, pp. 3.5-3.8 (1985) 7) MPO: Resource Availability and Demands Alternative Investment Plans, Recommen- dations, Draft Final Report, Vol. II, National Water Plan Project, Ministry of Irrigation, Water Development and Flood Control, Govt. of Bangladesh, Dhaka, pp. 10.6-10.10. 11.1, 15.5-15.14 (1985) 8) MPO: Resources. Vol. II, National Water Plan Project, Ministry of Irrigation, Water Development and Flood Control, Govt. of Bangladesh , Dhaka. pp. 9.2, 9.3. 9) MPO: Sector Analysis, Vol. I, National Water Plan Project, Ministry of Irrigation , Water Development and Flood Contro 1, Govt. of Bangladesh, Dhaka, pp. 7.6, (1986) 10) Bangladesh Bureau of Statistics: Statistical year book of Bangladesh 1986, Govt. of the People's Republic of Bangladesh, Dhaka, pp. 281-283 (1986)

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