BMP options for highway and road runoff management
Link to this table

BMP Type Objective BMP Examples Safety Considerations
Highway swale 2.png
Diffuse flow energy from concentrated roadway surface before discharging over a slope; reinforce discharge point and slopes; promote sheet flow Compost sock (see image), bio-slope, outlet reinforcement, spray mulch, compost rip rap matrix (between rocks) May increase slipperiness of shoulder slope
Catch basin insert.png
Filter litter and debris from flow as it enters catch basins; preferably with pollutant sorbents 2 Catch basin insert (see image); hooded outlet pipe; oil and grease separator Might become heavy for maintenance crews to lift; must be cleaned to prevent clogging
Gross solid removal device.png
Route runoff through a screen or filter material to remove litter and treat particulate, and the associated nutrients, toxics and hydrocarbons Gross Solids Removal Device (GSRD) (see image), compost tube inside of rock weep, Often contained in confined space; maintenance crew will need confined space training
Geotextile wrapped trench.png
Diffuse heat from road and parking surfaces prior to discharge to sensitive waters Geotextile wrapped rip rap thermal tube (see image), infiltration trench None
Highway swale.png
Provide vegetated swale drainage systems with low head grade breaks in rural sections “Living ditch” (see image), check dams (rip rap, bio-weeper, bio-ditch filter) Can hold water for a time after runoff occurs so need to keep design depths shallow; grade breaks can be obstruction hazard to recreational vehicles using swale
Particle skimmer.png
Retrofit stored water BMPs with proper outlet and skimmer devices Particulate skimmer (see image), baffle weir, Faircloth skimmer (proprietary device) None
Pervious pavement.png
Use pervious paving material in areas that will support it Pervious asphalt and concrete (see image), paving blocks None for pavement; blocks can pose walking problems if not designed properly; recommendation for minimal salt use could mean ice might be present for short periods
Island rain garden.png
Route water to bioretention, filtration or infiltration areas where conditions appropriate Rain garden (see image) Near-road locations could possibly impede vision at intersections if vegetation not kept low; water might collect adjacent to roadway
Curved channels.png
Geomorphically stabilize channels Cross vanes, fish steps, curvilinear channel restoration (see image), reinforced streambank, grade adjustments, revetments, root wads None
Off line pool.png
Use off-line storage in available floodplain, open space Off-line pools (see image), enhanced floodplains, wetland restoration/preservation None if kept away from areas where vehicles expected to travel or go off of the road
Under street infiltration trench.png
Use sub-grade storage with or without perforations to allow for storage and infiltration where drainage determined not to impact road structure Under street infiltration trenches (see image), vault storage to replace surface ponds, rest areas parking lots Maintenance crew will need confined-space training

1Use of proprietary devices or images merely for illustrative purposes and does not mean endorsement of a product
2Note that housekeeping practices like street sweeping and chemical use are discussed in the Pollution Prevention section

This page was last edited on 4 August 2022, at 20:03.