Grass Rooting Affects Hptrm Performance on Dikes Embankments in Florida.

Earthen levee embankments are susceptible to wave overtopping during flooding events from natural forces such as hurricanes. In previous wave overtopping tests conducted at the Colorado State University (CSU) Wave Overtopping Test Facility have shown healthy grass cultivated on the landward-side slopes constructed from clay surpassed current conventional design guidance for tolerable wave overtopping rates. However, dikes embankments in Florida are constructed using native soils composed of sand, silt, and shell fragments that are characterized as being more highly erosive.  To lessen overtopping erosion, high performance turf reinforcement mats (HPTRM) may provide greater resistance compared to highly managed vegetation. Therefore, overtopping tests were conducted at CSU evaluating HPTRM vegetated with bahiagrass (Paspalum flugge) at various canopy coverages.  Post overtopping simulation, bahiagrass growth characteristics were correlated between hydraulic loading magnitude and overtopping duration for HPTRMs and controls.  The purpose was to develop overtopping guidance for bahiagrass on sandy soils.