What are the advantages and disadvantages are associated with the construction, function, and operation of dams built of different materials?

Construction wise advantages and disadvantages of earthen dams:

Advantages:

• Availability of earth material: Earth is readily available in most parts of the world closed to possible dam sites. 
• Easy handling of earth: Earth can be excavated by hand, transported in baskets and compacted with cattle walking over it. In suitable situation,  earth ca be moved and handled with latest machinery.
• Foundation condition: Earth dams are suited to the sites where masonry dams can-not be used for structural reasons. These dams can be constructed even on compressible foundations. The intensity of foundation stress due to earth is less than that due to solid masonary.
• Cost of construction: The cost of construction of earthen dam is less and approximately one half of a concrete dam.
• Apart from above advantages, earthen dam has one more advantage i.e its simple and easy construction steps and design also.

Disadvantages: Apart from several disadvantages, earthen dam has some disadvantages also which are as follows:

• If the compaction is not adequate or proper, the foundation becomes weak an d prone to failure.
• Dam construction requires a huge place and capital.

Function wise advantages and disadvantages:

There are several advantages of earthen dams but there is one disadvantage in the fact that the earthen dam has a high risk of being damaged by the heavy flow of water. Hence additional protective structures may have to be constructed.

Operation: Earthen dams performs its operation satisfactorily i.e for irrigation purposes or for stopping flood situations in the form of detention dams. These dams generally serve the primary purpose of retaining water, while other structures such as flood gates are used to manage or prevent water flow into specific land regions.

Advantages:

• These are more suitable in steep valleys where earth dams are liable to slip.
• These are found more advantageous in the regions of high rainfall and heavy snowfall.
• A gravity dam does not fail suddenly. Their failure can be predicted well in advance so that loss of life and property may be saved.
• Their cost of maintenance is less as compared to other dams and benefit of cost ratio is highest.
• Such dams, when built into strong foundation can be constructed up to a maximum possible height.
• In these dams, surplus water may be discharged through the sluices provided in the body of the dam or over spillway built in a suitable location of the dam.

These types of dams are majorly used now a days because of its ability to adopt any shape and low maintenance cost and less permeability due to high grade concrete.

Disadvantages:

• Although its maintenance cost is low, but its initial cost is very high.
• Construction period is very more as compared to earthen dam.
• Skilled labor is required for the supervision of concrete dams.
• Concrete dams are very heavy. So, it require a strong foundation.