Band 7.5 IELTS report

The following is a report submitted by one of our students. It may have spelling or grammar mistakes.

The provided pictures illustrate two solutions – with and without stopbank – for protecting houses from being damaged by floods in flooding-vulnerable areas.

Both methods require houses to be built on a higher level above the ground, which allows the water to go underneath the building without touching the house floor level. Therefore, a precise estimation of 100-year flood level is required by either solution.

The first solution is to build a stopbank which is a bit higher than the level of 100-year flood. The freeboard on the stopbank is used for stopping the flood from getting into the inner land. Buildings are built above an internal ponding, which is used for storing the water comes from the runoff of internal rainfall. In the bottom of the stopbank, a floodgate needs to be built on the berm, which allows the water in internal ponding goes out to the river.

An alternative solution can be applied when there is no stopbank. In this case, houses need to be built higher than it is in previous solution. Without the stopbank, water will flood into the inner land. A 300mm freeboard, therefore, is required between the house floor level and the 100-year flood level.