• Till the 1950s – Flood Management with small dykes under individual control, irrigation from river water using manual or semi-mechanical lift.
• Water Sector Master Plan of 1964 -- Concepts of major flood control, drainage and irrigation projects. This implementation continued until 1971. The objective was safe paddy cultivation.
• IBRD Review 1972 -- Concept of small scale project with emphasis on irrigation using ground water. Large coverage could be achieved by private sector initiative. Food grain self sufficiency was achieved but with adverse impacts such as lowering of ground water and arsenic pollution.
• 1983-1989 and 1990-1995 -- Master Plan Organisation (MPO) and Surface Water Simulation Modelling Programme (SWSMP). Flood Action Plan (FAP) considered 26 components after the floods of 1987 and 1988, initially on the flood, and finally on round-the-year water management. Regional study on environmental impacts was introduced. However, due to a lack of quality control in managing the studies at one times and results of pilot studies not in, the FAP could not provide definite and useful output. Simultaneously Flood Forecasting was introduced using mathematical model to support flood management. Major and important secondary rivers were covered. Due to limited upstream information, lead time was inadequate.
• A new National Water Management Plan has been initiated in 2004. The plan is guided by the National Water Policy introduce in early 1999.
• 2004 -- The National Water Management Plan (NWMP) was approved by the Government of Bangladesh.

Achievements and impacts
So far 60 per cent of Bangladesh has been brought under flood control and drainage. Many of the projects are not well maintained due to lack of funds. No tax rule exists to recover the cost. Adverse impact of water logging, disallowing available necessary flooding, closing navigational routes and an overall shortage of fresh water fish are seen. While the stakeholders are theoretically in favour of flood management, their participation is still not ensured. Operation of the structures, maintenance of drainage canal and participation of decision makers has been missing.

River monitoring is a necessity which requires large sums for hard material and was neglected until recently. While river monitoring on a regular basis can reduce the severity of erosion and, thereby, the costs of initial construction and maintenance, there is no systematic measure being taken for this.

Policy and Reforms
Management actions taken at one location can influence the geomorphology, water quality and ecosystem of other areas, even far beyond the project area. Recent approaches to river management are multi-objective, balancing beneficial uses for agriculture, fisheries, water supply, navigation with the protection and enhancement of the riverine and flood plain habitat and water quality. These emerging concepts make room for the physical processes to drive the ecological restoration by natural progression, rather than engineering.

There is a gradual shift of the government policies of the early 1990s towards a more comprehensive and holistic approach in water management from expensive structural measures for flood control and drainage. There is a new consensus among stakeholders, professionals and the policy makers on the need for integrated water resources management, reflected in the Bangladesh Water and Flood Management Strategy (FPCO, 1996).

The Flood Action Plan culminated in the publication of the Bangladesh Water and Flood Management Strategy (BWFMS) in 1996. This recognised the limitations of earlier plans, which had focused too heavily on agricultural development without adequate consideration of the needs of other sectors. The BWFMS recommended that the government should formulate a National Water Policy together with a comprehensive National Water Management Plan (NWMP).

The government acted promptly to implement these recommendations. The National Water Policy (NWPo) was prepared and published in January 1999 following endorsement of the National Water Resources Council (NWRC). A new National Water Management Plan (NWMP) was formulated and approved in 2004.

The National Water Policy
The NWPO provides an overall framework for future management of the water sector. Directions are provided on such issues as overall basin-wide planning, water rights and allocation, public and private involvement, public investment, water supply and sanitation, fisheries navigation, agriculture industry and environment. The document is intended to guide both public and private actions to ensure optimal development and management of water that benefits both individuals and society at large.

Other related policies
In 1998, the National Policy for Safe Drinking Water Supply and Sanitation (NPSWSS) was published. The main objective of this policy is to improve public health and produce a safer environment by reducing water borne disease and contamination of surface and groundwater. In this policy the government recognised the importance of increasing participation of users including active support and involvement of other partners, such as NGOs, market-oriented business organisations and similar private organisations in water and sanitation development.

The National Agricultural Policy (NAP) was issued in 1999. The main goal of this policy is to maintain self-sufficiency in food. It also aims to ensure that agriculture is profitable to farmers by improved input supply and credit. One important aspect of this policy is that it sets out clear agenda to promote and develop socially and environmentally-friendly agriculture.

As early as 1994, the National Forest Policy (NFoP) proposed approximately 20 per cent afforestation by the year 2015. For the first time multiple uses of the Sunderbans were recognised including water, forest and fish. Issues such as global warming, desertification and control of trade of wild birds and animals were also addressed.

The National Fisheries Policy (NFiP) of 1998 aims to enhance fisheries production and improve socio-economic conditions for households where capture fishing is the main activity; to meet the demand for animal protein; to boost economic growth by export of fish and fisheries product; and to maintain ecological balance. The policy highlights the need to conserve fish habitats, to prevent further drainage of standing water bodies for agricultural development.

The National Environmental Policy (NEP) of 1992 is broadly similar to the National Fisheries Policy. This policy also highlights the need to maintain ecological balance and overall development through protection and improvement of the environment. It seeks to identify and regulate activities that pollute and degrade the environment to ensure environmentally sound development in all sectors. One important aspect of this policy is proposing to audit existing flood control and drainage projects on an emergency basis along with steps to modify these projects as necessary.

Assessment of policies
There are no major contradictions between national policies for different sectors with respect to water resources development in the country. However, there are no clear guidelines in the country as to how the actions required by different policies should be coordinated. Contradiction also arises due to gaps and interpretation of policy issues.

A major gap in the NPSWSS is its obscurity in stating the need for regulating private sector activities to ensure water quality. Neither the treatment levels nor the industrial effluents are discussed in the policy. No reference has been made to the interaction of wells for drinking water and irrigation. The NPSWSS also does not clearly address the coordination of activities of different agencies in other sub-sectors. The NAP objective to maintain food self-sufficiency along with issues related to water requirement and land use to meet the policy objective need to be adequately addressed.

The NFiP policy aims at expanding the capture fisheries resources with a target to export surplus. However, this may trigger conflict with the agricultural sector in the management of water bodies. Another area of conflict is advocating banning of discharge of industrial wastes, agro-chemicals and fish-farm chemicals into water bodies. This may again give rise to conflict with the target of NAP to maintain food self-sufficiency by expanding HYV crops. There are no major conflicts between NEP and other policies except for auditing the FCD projects. The NWPO does not provide any guidelines or direction in this regards.

Water Development Issues: Today and 2025
The population projection for 2025 for medium fertility decline is 181 million, taking 1995 as the base year, according to National Water Management Plan (NWMP). NWMP also predicts that the urban population will grow at a rate of 8 per cent per annum, which means 73 million inhabitants in urban areas in 2025 compared to 27 million in 2000; an increase of 2.7. According to the draft Development Strategy formulated by the National Water Management Plan Project (NWMPP), under the medium economic growth scenario the GDP will rise from 2021 billion in 1999-00 to 7965 billion in 2024-25.

Considering medium economic growth and medium fertility decline, it has been estimated by the NWMP that an additional demand of 9.5 million tons of food grains will be created in 2025 compared to 2000. Annual fish consumption will increase from 1.68 Mt/a to 4.43 Mt/a in 2025.

Increase in population and economic activities will be the main driving force in determining the water demand in the coming years. Some indication of the development scenario could be obtained from the estimated land distribution in 2025.

Changes in the area of river, forest, urban and rural settlements will not be appreciable. However, the major concern is the absolute decline of approximately 1.4 Mha of agricultural land. This is largely due to the expansion of fish production on agricultural lands. In that case, the rate of increase of yield should be 2 per cent per annum to maintain food self-sufficiency. In order to increase production, most of the irrigable areas will need to be brought under irrigation. A 1997-98 estimate by NMIDP shows that only 2.83 Mha out of a potential 7.89 Mha is irrigated in the Rabi (winter) season. However, it must be recognised that getting water to all irrigable lands at an affordable price will be difficult. The above estimates do not consider the effect of global warming. It is envisaged that global warming will have a major impact on crop production due to prolonged dry season.

Flood mitigation and management
Floodplains of the major rivers and their tributaries and distributaries cover around 80 per cent of Bangladesh. As a result of very flat topography 20 per cent of the lands are inundated due to spilling of the rivers each year during the monsoon period (June-September). Rainfall of high intensity and long duration in the river catchments causes drainage congestion within the country due to inadequate conveyance capacity of the rivers. The situation becomes severe when peak flow in the rivers synchronises with high rainfall. The nation experiences around 37 per cent inundation due to floods every 10 years. In 1988 and 1998 more than 60 per cent land was inundated.

During the last 50 years, hundreds of kilometres of embankments have been constructed by Bangladesh Water Development Board (BWDB), Local Government Engineering Department (LGED) and local authorities (zilla parishad/union parishads/pourashavas). As time progresses and more projects are completed, interdependency of these kinds of flood mitigation measures with the surrounding water environment has resulted in a number of adverse impacts. Some of the adverse impacts include increase in the depth, duration and extent of inundation in the unprotected areas, increase in sedimentation rate in the drainage channels, increase in flood levels, drainage congestion in the protected areas, loss of fish habitats and breeding grounds. Due to inadequate maintenance of flood embankment, embankment breaches are common phenomenon. These embankment breaches are the cause of major flood disaster particularly in the areas on the right bank of Jamuna River. Therefore, mitigation measure for one hazard can cause a wide range of hazards in other areas.

Human intervention and associated impacts
Human intervention in the flood plains and in the water bodies has introduced large scale environmental, social and economic impacts. Conventional methods of engineering practices of analysis and design had to use simplified approaches without considering interactive responses from system interventions, which is inevitable in the complex river and flood plain system in Bangladesh. The designers had to opt for conservative design parameters to remain on the safe side, or to omit some very important issues which later proved to be the main reasons behind unacceptable hazards that took place within and around project area.

Freshwater withdrawal and salinity intrusion
Salinity in the coastal areas, particularly in the south-west region is a major concern. Salinity intrusion in the south-west has increased due to low fresh water flow through Gorai during dry season. The main reason is the withdrawal of water in the upstream resulting in degradation of the Gorai offtake. This has resulted in major adverse impacts on the environment and socio-economic condition in the area. The historic Ganges Water Sharing Treaty (GWT) with India signed in 1996 makes a certain quantum of flow available to Bangladesh during the dry season. The main challenge in the future will be to best utilise this additional flow to restore the Gorai and other rivers; arrest environmental degradation by salinity control; extend irrigation facilities; control of sedimentation. Diversion, distribution and management of this additional flow will require major interventions like a barrage on the Ganges, water control structures and distribution canal in the Ganges Dependent Areas (GDA). A detailed study on the feasibility of various intervention options should immediately be undertaken.

Sedimentation of rivers, estuaries and coasts
Each year a huge volume of sediment is being conveyed by the major rivers to the sea. Although it is difficult to quantify the volume of sediment accurately, estimates by different studies show that the quantity of sediment ranges somewhere between 0.5 to 2 billion tonnes per year. It is, however, reasonable to state that sediment load could be in excess of 1 billion tonnes per year. This is a potential resource, which needs to be harnessed in the reclamation of land in the coastal areas. An NWMPP estimate suggests that if 10 per cent of the sediment is deposited on 31,000 km² land with flooding deeper than 0.9m with a consolidation of 1.5t/m, then the thickness of the deposit would average 10mm per year. This is important for compensation of land subsidence which is typically 2mm per year.

Erosion of river banks
The seasonal variation of river flows causes variation in sediment transport and as a result, erosion of river banks occurs. The possible after effects are migration of bank lines, resulting in a loss of valuable lands. Previous studies have estimated that by the year 2025 around 3,575 km² area in the erodible river valleys of Brahmaputra, Ganges, Padma, Lower Meghna and estuary will be lost due to erosion. On the other hand, 3,665 km² land will be gained due to accretion in the same period. From these figures it may seem that the loss is not very significant. But this has major social, economic and environmental implications. Structural measures like river bank protection, canalisation etc. for mitigation for erosion in the extremely dynamic river valleys of Jamuna, Padma, Ganges or Lower Meghna would require huge investment in implementation and more so in maintenance. Planning of any such mitigation measure requires prediction of river erosion and the most suitable measure for mitigation based on their resulting impact upstream and downstream of the mitigation work. Remote sensing data can be used for study of pattern of changes to river plan form and bank lines. Mathematical models could be useful to predict river erosion, and study of different mitigation options and their impacts. Prediction of erosion for early warning can also save life and property.

Cyclone and storm surge
Bangladesh has over 700 km of coastline, which is exposed to recurring cyclones from the Bay of Bengal. The coastal areas have experienced over 42 major cyclones in the last 125 years. These cyclones cause immense damage to the coastal social and economic life and to the environment. In 1991, the coastal areas experienced a storm with a surge height of 4.0-5.0 m, killing 140,000 of the population and damaging livestock, crops, property and infrastructure in the area. Since the 1960s a large number of polders have been constructed in the tidal plains of the south as mitigation measures against tidal surges and saline water intrusion. A large number of cyclone shelters have also been constructed to save life in the event of a storm surge.

One of the major mitigation measures are land-use policies, which should guide development activities in disaster prone areas. The land-use policy should be based on analysis of risk due to hazard. Deterministic models can be used to simulate any events and GIS could be very a handy tool for risk mapping based on risk analysis on the basis of an inventory of the property at risk to the hazard, and estimates of different intensities of hazard events. Probabilistic models could be used to take into account of the whole range of likely events by assigning probabilities to each range of events and estimating the damage that would be expected to occur as a result.

Water stress
Agricultural drought is a common phenomenon in many areas of Bangladesh in post monsoon and dry season. In major cities, scarcity of water for drinking and sanitation is a major problem. Main causes of drought are limited rainfall, high temperature associated with low humidity and withdrawal of water in the upstream. Over withdrawal of groundwater is causing lowering of groundwater in many areas; as a result, many Shallow Tubewells (STW) are becoming inoperable. Moreover, low flow in rivers in the dry period and lowering of groundwater table is causing environmental problems like salinity intrusion in surface and groundwater, increase in the concentration of pollution in surface water, sedimentation etc. The problem becomes multifaceted when there is scarcity of ground water during the monsoon in most years, especially in the flood-controlled area. This reveals the significance of annual flood plain's inundation for ground water recharge.

Urban water supply and sanitation
Pollution from human and industrial sources is the main water quality problem in the river systems near urban areas. Buriganga in Dhaka and Karnafuli in Chittagong are the worst affected. Other rivers are also showing gradual decline in water quality. It has been estimated that urban population will increase by 2.7 times by 2025. The gross daily water demand in the major metropolitan cities (Dhaka, Chittagong, Khulna and Rajshahi) will rise from the present 2460 Ml/d (million litres per day) to 7970 Ml/d assuming a system loss of 20 per cent. There is already a major shortage of required supply of safe water. Due to over abstraction and loss of recharge areas, the groundwater table in Dhaka has declined at an alarming rate over the last couple of decades. A 1997 study by Institute of Water Modelling (IWM) has shown that the maximum drawdown due to groundwater abstraction was 25m. However, this drawdown could have been reduced to 15m by conjunctive use of surface and groundwater. Based on model study, the IWM recommended the use of surface water during wet season from the rivers surrounding Dhaka and use of groundwater during dry period. It may be mentioned here that cost of treatment of surface water will be lower in wet season because of lower pollution level. Recharge during wet season will raise the groundwater table, which will reduce the cost of groundwater abstraction during dry season. Alternative sources like River Jamna, which is only 80km away with reliable flow needs to be investigated. Conjunctive use in other major cities and urban areas should also be studied. Other options relate to more stringent regulations implemented on the ground relating to protection of the quality of water and reduction of wastage and unaccounted-for water. Community participation in the process is vital. Demand management by imposing tariffs could be useful to discourage wastage of water. Private sector management of water supply system could be more efficient in the management of demand and quality services.

Dhaka has the largest piped sewerage system in Bangladesh; however, the existing system serves only 20 per cent of the city. Of this only 3 per cent reaches the DWASA sewage treatment plant at Pagla, the rest leaks into ground or surface water system, which cause widespread pollution. 40 per cent households in Dhaka have septic tanks with soak wells. In the future, with the increase in population density, the quantities will not only exceed soak well capacity, but high land values will discourage the setting aside of land for such purposes. Therefore, immediate measures to collect and carry the effluent for treatment and disposal are necessary.

Arsenic contamination of groundwater
The issue of arsenic is now the most important environmental concern of Bangladesh. In recent times arsenic in tube-well waters has upset the drinking water supply from groundwater. Arsenic has turned into a national health issue, groundwater users panicking as a result. Out of 64 districts, arsenic contamination in groundwater has been detected in 59 districts. The most common mitigation measure being taken is identifying the tube-wells with arsenic level crossing allowable limits for drinking water. Various agencies are working all over Bangladesh in testing tube-well water for arsenic. The testing methods have not yet been standardised, field activities are not coordinated, valuable information from field investigations is not properly archived for further use. There is an urgent need to develop an arsenic database, which should include information on the tube-wells being affected, the population under threat, mitigation