Explanation:

Economical height of a dam refers to the height at which the cost per unit storage is minimum. The cost per unit storage is calculated by dividing the total cost of constructing the dam by the total storage capacity it provides. This is the most important factor for determining the economical height of a dam because it directly impacts the cost-effectiveness of the project.

Factors affecting the economical height of a dam:

1. Cost of construction: The cost of constructing a dam includes various expenses such as excavation, concrete work, reinforcement, transportation, and labor. The higher the height of the dam, the higher will be the cost of construction.

2. Storage capacity: The storage capacity of a dam is directly proportional to its height. The higher the height, the greater will be the storage capacity.

3. Benefit-cost ratio: Although the benefit-cost ratio is an important factor, it is not the most important factor for determining the economical height of a dam. It is used to determine the economic viability of the project as a whole.

4. Net benefit: Net benefit is the difference between the benefits and costs of the project. However, it does not provide information about the cost-effectiveness of the project.

Importance of determining the economical height of a dam:

Determining the economical height of a dam is important for the following reasons:

1. It helps in reducing the cost of construction by optimizing the height of the dam.

2. It ensures that the project is cost-effective and provides maximum storage capacity at minimum cost.

3. It helps in minimizing the environmental impact of the project by optimizing the height of the dam.

Conclusion:

In conclusion, the economical height of a dam is determined by the cost per unit storage. This is the most important factor for determining the cost-effectiveness of the project. The height of the dam should be optimized to ensure that it provides maximum storage capacity at minimum cost.