Dams that are built by rolling, rolling or carving these materials in various combinations of rock, gravel, sand, silt or clay are called Earth Dams or non-rigid dam,

Table of Contents

Benefits of earth dams

Despite the structural incompatibility of earth and water, many earth dams have been built with different types of earth and rock with stable conditions. The main advantages of earth dams are as follows:

1. Availability of Earth Material

Earth is readily available in most parts of the world close to potential dam sites. Now the knowledge of soil mechanics has further increased the possibility of stabilizing the unstable earth dam.

2. Easy handling of earth

Earth can be dug by hand, carried in baskets and compacted with cattle walking on it. In suitable condition, earth can be handled and moved with latest machinery.

3. Foundation Condition

Earth dams are suitable for sites where a masonry dam cannot be used for structural reasons. These dams can also be constructed on compacted foundations. The intensity of foundation stress due to soil is less than that of solid masonry. Due to the greater base width, the horizontal water pressure on the dams is distributed over a greater area and, therefore, the risk of slipping on weak foundations is minimized. The greater width of the dam foundation also reduces leakage through the foundation under the dam.

4. Cost of Construction

The most important advantage of an earth dam is its low cost as compared to a masonry dam. It is seen that the total cost of an earthen dam is about half that of a concrete dam.

Disadvantages of Earth Dams

However, earth dams have the following disadvantages.

Non-availability of material at or near the dam site.
Higher maintenance cost than a good concrete dam.
Earthen dams are unsuitable for spillways.