Flood control embankments along rivers – terminology Earthen embankments constructed parallel to river banks at some distance, primarily for flood protection, are commonly called what?

Introduction / Context:
Linear flood defences along rivers are used to contain high flows within the channel corridor and protect adjacent land. Understanding the terminology helps in interpreting design reports, environmental impact statements, and floodplain management plans.

Given Data / Assumptions:

• Earthen embankments set back from the river channel.
• Primary purpose is to reduce floodplain inundation during high stages.
• No special reference to reinforced concrete walls or sheet-pile systems.

Concept / Approach:
In many regions, the terms “levee” and “dike” are used interchangeably to describe earthen embankments built for flood control. “Flood wall” typically refers to a rigid wall (often concrete) rather than an earth embankment. “River wall” is less standard and may refer to revetments or quay walls rather than flood retention structures.

Step-by-Step Solution:
Match description: earthen embankments parallel to rivers → levees/dikes.Select the combined correct terminology → option (e) Both (c) and (d).

Verification / Alternative check:
Technical literature and flood management agencies routinely use “levees/dikes” for earthen flood barriers, reserving “flood walls” for vertical, engineered wall systems.

Why Other Options Are Wrong:

• (a) Flood walls are rigid walls, not earthen embankments.
• (b) River walls are bank protection/quays, not necessarily setback flood embankments.
• (c) or (d) individually are correct but incomplete since both names are accepted.

Common Pitfalls:
Assuming armoured revetments are levees; revetments protect banks from erosion but do not necessarily provide flood storage or conveyance control like levees/dikes.

Final Answer:
Both (c) and (d)