Flaring gate piers (FGPs) can change how water flows over weirs, improving energy dissipation but possibly affecting water discharge. By testing different conditions, researchers found that weirs with FGPs had backwater curves and narrower plunging jets. The discharge coefficients for weirs with FGPs stayed consistent regardless of weir length. A new equation was developed to predict discharge coefficients for weirs with FGPs, showing that coefficients increased with higher contraction ratios and water heads. The effect of contraction angles on discharge coefficients was minimal.