Effective Post-Construction Best Management Practices (BMPs) to Infiltrate and Retain Stormwater Run-off

Performance analyses of newly constructed linear BMPs in retaining stormwater run-off from 1 in. precipitation in post-construction highway applications and urban areas were conducted using numerical simulations and field observation. A series of simulations were conducted using an idealized catchment on a four-lane highway located on sites with soil types ranging from clayey to sandy material across state of Illinois. The use of turfgrasses and prairie grass vegetative surface covers in pre-BMP scenarios in promoting infiltration and reducing stormwater run-off were investigated. Three types of BMPs—bioswale, infiltration trench, and vegetated filter strips—as well as combinations thereof, were studied for determining their ability to control stormwater run-off in an idealized catchment. This report also documents the maintenance cost, construction cost, and life-cycle analyses of those BMPs to identify cost-effective solutions. The effects of erosion and a sediment accumulation rate of 1 t/ac/y on BMPs during the 2- year and 10-year lifespans of bioswales and infiltration trenches were studied using full-scale field tests. The simulation and field test results provide insight for developing guidelines for cost-effective BMPs to control stormwater run-off in linear projects.IDOT-R27-141Ope