Hydrology of Synthetic Turf Fields: Modeling Approach with Field Data

The hydrology of synthetic turf field (STF) drainage systems is poorly understood, which complicates their design. Field data are collected and used to parameterize computer models simulating the hydrology of a synthetic turf sport field. A model was employed to simulate infiltration through the synthetic turf, into the subsoil matrix, and free drainage into the perforated underdrains. The output from that model was routed using another model to simulate flow through the subsurface pipe drainage network to the system outfall. The drainage model was calibrated with actual hydraulic parameters obtained from field substrate material measurements, observed rainfall hyetographs, and measured discharge hydrographs for several storm events. Output from the calibrated STF drainage model closely matched the observed outlet hydrograph. Model output was then applied to investigate whether the classic rational formula was an appropriate tool for predicting peak flows from synthetic turf fields. It was determined that a single unique $C$ factor in the rational framework could not adequately account for the more complex rainfall-runoff response of the synthetic turf drainage system. The implications of this new hydrologic model of STF performance are discussed.