Hydraulic Performance of Full Flowing Perforated Pipe Underdrains Surrounded by Loose Laid Aggregate

Low Impact Development (LID) Best Management Practices (BMPs) are becoming increasingly popular. Many of these BMPs work to increase the infiltration of runoff into the underlying soil. However, some BMPs, including porous pavements and infiltration trenches, sometimes need additional sub-surface drainage to comply with local drawdown regulations or to prevent the trench or pavement filling with runoff leading to water percolating up to the surface. Unfortunately, there is very little information available on how these drains perform. The goal of this research is to aid engineers by developing stage – discharge relationships for a range of commonly available perforated pipes.