Hydraulic structures – material of construction for weirs\nIn water resources engineering, a permanent weir used for flow measurement or control is generally constructed from which materials?

Introduction / Context:
Weirs are overflow structures that raise upstream water level and/or measure discharge. For accuracy and durability, they must maintain crest geometry under hydraulic and environmental loading. Materials influence stability, service life, and maintenance.

Given Data / Assumptions:

• Permanent installation on streams/canals for long-term service.
• Need for dimensional stability of crest and abutments.
• Exposure to weathering and hydraulic forces.

Concept / Approach:
Masonry and concrete provide mass, rigidity, and resistance to erosion—critical for maintaining crest shape and energy dissipation arrangements. While thin-plate (sharp-crested) weirs can be fabricated from metal for lab or temporary field use, permanent river training and measurement weirs are commonly masonry or reinforced concrete.

Step-by-Step Reasoning:

Verification / Alternative check:
Standard hydraulic texts and design manuals illustrate ogee, broad-crested, and sharp-crested permanent weirs in masonry or RC for field use.

Why Other Options Are Wrong:

• No: contradicts typical civil engineering practice.
• Timber only / steel plate only: applicable mainly to temporary or experimental setups, not the usual permanent case.

Common Pitfalls:
Equating laboratory weir plates with field weirs; the latter require robust civil works.

Final Answer:
Yes