Following are the various benefits of dams:
What are the various benefits and problem of dams?

1. The dams store the water creating a tank or a reservoir and raise the level of water throughout the year.

2. The water stored by the dam flows through the canals and provide irrigation facilities for the adjacent lands in the lower areas.

3. The stored water, also flows. Through hydraulic turbines producing power to be used in houses and industries.

4. Water released from the dam in uniform quantities guarantee water for fishes and other wild life in the stream below the dam.

5. Water released from the dam in large quantities, permits river to overflow.

6. Big dams help in checking floods Flood water can be held back and released gradually over longer periods of time without overflowing the river banks.

7. They help in reducing soil erosion which would have occurred due to floods which carry off the fertile top soil.

8. Lakes or reservoirs created by dams provide recreation areas for water sports and angling They provide employment to the people living in that area. 

9. They are a source of economic upright and growth.

Following are the problems of dams:

1. They cause huge loss of forests, flora and fauna.

2. Dams cause concern when they submerge large areas of fertile land and displace a large number of tribal people. The relief and rehabilitation programmes offered by the governments are always inadequate. Thousands of people displaced by some projects are yet to be resettled amicably.

3. Different types of fish and marine population is developed in the stationary water of the reservior than those in the flowing river water. The ecological change has significant effect on the environment and needs suitable management.

4. Run off from cleared areas is much greater than that from forested lands.

5. Large scale deforestation is a great risk which effects the environmental balance.

6. They increase the occurrence of water borne and soil bornediseases like malaria etc.

7. They change microclimate, cause variations in water table and increase. Seismic activities due to pressure of water.

8. The silting rate is a serious problem. Indian dams have generally silted up much faster than predicted. Silting of dam reservoirs make them useless and the hydroelectric power project become nonrenewable source of energy.

9. Dam can alter water temperatures and water becomes abnormally warm in summer. As a result water loses its dissolved oxygen and the organisms begin dying

10. Dames release water which is significantly colder or warmer than the river water. The river water thus loses its ability to support algea which leads to collapse of the rivers food web, so it leads to loss of flora and fauna.

11. Dams give rise to loss of land. fertilely along the river due to deposition of nutrients.

12. Dams cause water logging and salinity due to over irrigation.

13. Laking an overall view, the benefits from the dams over the problem caused by them.