Surface Overflow Rate vs Weir Overflow Rate

03/24/26

“What’s the difference between the surface and weir overflow rate in environmental engineering?”

Environmental engineers often have to contend with surface overflow rates and weir overflow rates. But what do these mean, and how are they different? Well, the surface overflow rate measures the upward flow of water per surface area of a sedimentation tank/clarifier to determine if physical particles will settle out. In contrast, the weir overflow rate measures the flow volume moving along the length of the weir per weir length. The weir overflow rate determines how turbulent the incoming water over a weir is and how that might affect effluent quality. This is the difference between Surface Overflow Rates vs Weir Overflow Rates.

• Earth/Climate science
• Engineering
• Urban Systems