WATER & ENVIRONMENT RELATED ISSUES : 

The most important ecological variable affecting the environment and sustainable development in Bangladesh is water. Both the rapid population growth and the related increase in demand for water, as well as the decreasing supply of surface water during dry season, seriously affect water resource availability. The water issues affect almost all sectors of the country. These relate to low surface water flows, loss of wetlands, lowering of the ground water table, flooding, and water quality.
There is an increase in the use of water or irrigation, often from ground water sources. There are indications of a lowering of the water table due to indiscriminate use of ground water.
Bangladesh is a riverine country. The rivers serve as source of irrigation, means of transportation, sink for all sorts of industrial and domestic wastes as well as major sources of water for all domestic purposes. The rivers are continuously being polluted for unsustainable activities. According to the findings, the major pollution in rivers are attributed from sewerage pollution, infectious agents contaminate surface water from human excreta, domestic and hospital wastes. As almost all the industries do not use any treatment for effluent, pollution in the rivers and the surrounding areas are concentrated. Increasing use of agro-chemicals and heavy metals in industry contaminate the groundwater. While organic and chemical pollution sources are of concern to fisheries, Dissolved Oxygen (DO) in water is affected by oxygen demanding wastes from rayon mills, paper mills, tanneries and food processing
plants. Withdrawal of water from the Ganges at the upstream through Farakka barrage has also a cumulative effect on the overall eco-system in Bangladesh causing desertification in the north and increasing salinity in the south.

Water Pollution in Bangladesh can be summarized as follows : 
1. Water pollution is widespread and has a strong negative impact on human health. Pollution continues unabated causing a number of water borne diseases. 2. Industrial pollution is localized but untreated. Industrial wastes are dumped into rivers causing pollution of both the terrestrial and aquatic environment. 3. Agro-chemical pollution is feared as residues are exposed to enter the food chain.
4. Pollution in the Bay of Bengal due to crude spillage, handling of tankers and ships, ship breaking activities, refinery works and other spillage. Deforestation
Deforestation is possibly the most serious and widespread of the environmental problems facing Bangladesh.

Major causes of Deforestation include :

1. Commercial logging
2. Shifting cultivation
3. Complacency or lack of enforcement of forest rules and regulations.
4. Fuel wood consumption or extraction.
5. High population growth causing a high demand for food and fuel wood. 
6. Shrimp culture.

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