Capacity (\( Q = \frac{a \sqrt{2gH}}{\sqrt{1 + K_e + K_b L}} \)):

Where:

• \( Q \) is the flow capacity, in cubic meters per second (L³/T).
• \( a \) is the conduit cross-sectional area, in square meters (L²).
• \( H \) is the head causing flow, in meters (L).
• \( K_e \) is the entrance loss coefficient.
• \( K_b \) is the loss coefficient for bends in the culvert.
• \( L \) is the length of the flow path, in meters (L).