Weir loading is evaluated per which unit length of the weir?

• A. Linear Foot
• B. Square Foot
• C. Meter
• D. Cubic Foot

Answer: (A)

Weir loading is the discharge that passes per unit length along the crest of the weir. Since the flow over a weir is spread across its length, engineers express how much water passes for each foot of crest. That’s why the appropriate unit is a linear length—per linear foot of crest. In practical terms, the loading is given as flow rate per foot of crest (for example, cubic feet per second per foot of crest).

Example: if 200 cubic feet per second flows over a 40-foot crest, the weir loading is 5 cubic feet per second per foot of crest.

The other options don’t fit because they involve area (square foot) or total volume (cubic foot) or a metric unit (meter) rather than the per-length measure used for crest loading.