Who should determine the depth and width of a weir opening?

• A. The contractor
• B. The property owner
• C. A design professional
• D. The supplier

Answer: (C)

Setting the depth and width of a weir opening is a hydraulic design task that directly affects how the feature handles flow, safety, and maintenance. This requires applying flow calculations, head loss considerations, debris handling, and local code requirements. A design professional—such as a licensed engineer or landscape architect—has the training to analyze site conditions, expected water flow, and safety factors to specify the correct opening size. The contractor can build according to that plan, and the supplier can provide the right components, but the actual determination of dimensions should come from someone with the authority and expertise to ensure the system works reliably and safely. Choosing a professional ensures the design accounts for drainage needs, site constraints, and code compliance, reducing the risk of over- or under-sizing the opening.