What features does a sedimentation basin overflow weir typically have?

A sedimentation basin's primary function is to allow particles to settle from the water through gravitational force. The overflow weir is an essential component in this process as it allows the clarified water to exit the basin while preventing resuspension of settled solids.

The presence of notches in the overflow weir design serves a crucial purpose: they provide a means to control and stabilize the flow rate. This design ensures that the water flows over the weir in a uniform manner, which helps to maintain consistent hydraulic conditions. Uniform flow over the notches optimizes the performance of the sedimentation basin by minimizing turbulence that could disturb settled particles and allows for better sedimentation efficiency.

This feature also aids in operating the sedimentation basin under varying flow conditions by ensuring that the weir can manage changes in influent flow rates effectively, thereby preventing problems like overflow or underflow.