Operation & Maintenance

How to Maintain a Weir Box

Although simple devices, Weirs Boxes do require periodic maintenance to provide accurate flow measurement.

The Weir Box Installation

• Inspect the weir pool floor, removing sediment and debris as necessary
• Verify that the crest is horizontally and vertically level.
• Verify that the crest is at least 2 H_max above the maximum downstream water level.
• Clean the crest of any debris, ragging, vegetative growth, etc.
• Inspect the weir crest for nicks, burrs, rust, ice, or any other condition that affects flow over it.
• Verify that the zero elevation at the point of measurement is the same as the bottom of the weir crest.
• Inspect the weir plate / carrier for signs of leakage. While the weir plate / carrier are factory sealed, the stresses of shipment and installation may require that additional sealing be conducted after the weir box has been installed.
• Inspect the inlet and outlet end connections for signs of leakage.

Downstream Channel

• If the discharge is free-spilling, inspect the downstream channel for signs of scour – reinforcing the channel as necessary.
• Remove any debris, growth, etc. which may impede flow through the downstream channel.