A Case Study of Infiltration Gallery Water Flowrate to the Bandau Intake

This case study investigates the flow rate of water from an Infiltration Gallery (IG) to the Bandau Intake (BI) and aims to recommend solutions to ensure sufficient water supply. Although the IG effectively supplies raw water to Simpangan Intake (SI), the BI experiences shortages due to design and construction challenges. The study employs fluid mechanics principles, including the Manning and orifice equations, to analyze water flow dynamics over a 30-meter concrete channel. Three cases are examined: the original design, the actual constructed system, and a hypothetical scenario without an orifice. The findings reveal that the actual constructed system achieves 95% of the design flow rate (4.73 m³/s vs. 4.94 m³/s), meeting most requirements but falling short of the BI’s needs. In contrast, the hypothetical third scenario results in backflow (？3.15 m³/s), highlighting the significance of proper channel configuration. Limitations arise due to the shallow depth of the BI, necessitating adjustments from the original design. Recommendations include conducting detailed surveys to redesign the system with booster pumps to enhance flow rates and ensure adequate water supply. The study underscores the importance of adaptive engineering in overcoming real-world constraints to optimize water resource management.