Weir Flow Discharge Calculator
Calculate flow rate over weirs including rectangular, triangular, and trapezoidal configurations
About this calculator
The Weir Flow Discharge Calculator determines the volumetric flow rate of water flowing over different weir configurations including rectangular, triangular, and trapezoidal designs. This essential hydraulic engineering tool helps water management professionals, civil engineers, and irrigation specialists accurately measure and calculate discharge rates for flow control structures. The calculator applies established weir flow equations to provide precise measurements critical for water resource management, flood control, and irrigation system design.
How to use
Select your weir type (rectangular, triangular, or trapezoidal) from the configuration options. Enter the required dimensions such as weir width, head height above the weir crest, and any additional parameters specific to your weir shape. Click calculate to instantly determine the discharge rate in your preferred units.
Frequently asked questions
What is the difference between rectangular and triangular weirs?
Rectangular weirs have a straight horizontal crest, while triangular weirs have a V-shaped notch. Triangular weirs provide better accuracy at low flow rates.
How accurate are weir flow calculations?
Weir calculations are typically accurate within 2-5% when properly installed and calibrated, making them reliable for most engineering applications.
What head measurement is needed for weir calculations?
You need the head height, which is the vertical distance from the weir crest to the water surface upstream of the weir.