The V-notch weir is particularly suited for measuring what type of flow?

• A. Flows with High Solids
• B. Large, Turbulent Flows
• C. Small, Regular Flows
• D. Irregular, Varying Flows

Answer: (C)

V-notch weirs are designed to give a precise, predictable relationship between discharge and the water depth when the flow is small and steady. The triangular notch concentrates the flow through a narrow opening, so even a small change in water depth translates into a measurable change in discharge. That makes readings especially accurate at low discharges, which is why this device is ideal for measuring small, regular flows in open channels. It’s less suitable for high solids, large or turbulent flows, or flows that are irregular or highly variable, because solids can clog or distort the head measurement and the discharge–head relationship becomes less reliable under those conditions.