Flow Characteristics in Perforated Subsurface Drain of Drainage System Application: Case Study of Gate Fully Open with Longitudinal Slope 1/500

Subsurface drainage is part of a sustainable system's components. This component represents the infiltration stormwater into subsurface system for flow attenuation purposes. study examines parameters The laboratory validation perforated drains was conducted at longitudinal slope gradient 1/500 with Gate Fully Open. manning, n data obtained in these experiments varies several hydraulic parameters. Therefore, experimental relationship between characteristics drain components has been investigated. behavior determined. sub-critical and supercritical, turbulence occurred this study.