Suitable Spillway in case of Non-Availability of Space

In case of non-availability of space due to topography, the most suitable spillway is a shaft spillway.

Shaft Spillway

A shaft spillway is a type of spillway that is constructed vertically downwards through a dam. It is used when there is limited space available to construct a spillway. This type of spillway is also known as a Morning Glory spillway or a Glory Hole spillway.

Advantages of Shaft Spillway

1. Efficient use of space: The shaft spillway is constructed vertically downwards through the dam, which means it requires minimal space on the surface. This makes it a suitable option when there is limited space available.

2. High discharge capacity: The shaft spillway has a high discharge capacity, which means it can handle large amounts of water. This is because water flows through the spillway at high velocity due to the vertical drop.

3. Low maintenance: The shaft spillway requires minimal maintenance as the structure is simple and does not have any moving parts. This makes it a cost-effective option in the long run.

Disadvantages of Shaft Spillway

1. Limited control: The shaft spillway does not have any gates or valves to control the flow of water. This means that the flow of water cannot be regulated, and the spillway operates at full capacity at all times.

2. Risk of blockage: The shaft spillway has a narrow opening, which means that it can get blocked by debris or sediment. This can cause flooding upstream and damage to the spillway.

Conclusion

In summary, the shaft spillway is the most suitable spillway in case of non-availability of space due to topography. It has a high discharge capacity, requires minimal maintenance, and is a cost-effective option in the long run. However, it does have limitations such as limited control and the risk of blockage.