LID BMPs

LID controls are small-scale, distributed stormwater management devices that have the capability to meet multiple stormwater management objectives, including peak flow attenuation, volume reduction, and water quality improvement. LID controls use unit processes of the natural hydrologic cycle to meet these objectives. By making use of hydrologic cycle processes, LID attempts to mimic the natural function of the developed landscape. These unit processes are essential to natural stormwater management and LID controls:
 

• Infiltration – the downward movement of water into the soil via percolation through pore spaces.
• Evapotranspiration – the combined effects of evaporation and transpiration in reducing the volume of water in a vegetated area during a specific period of time.
• Interception – a form of detention and retention storage that occurs when leaves, stems, branches, and leaf litter catch rainfall.
• Conveyance – the transport of surface runoff, from where a raindrop falls to where it enters the receiving body of water.
• Detention – the temporary storage of stormwater, which is released over a period of hours or days after rainfall ceases.
• Retention – the permanent capture of a volume of stormwater that never enters the combined system.
• Reuse – capture of rainwater for later use by other processes such as non-potable water applications or landscaping.

LID BMPs

Bioretention area in
roadway median.
Source: LID Center
(click on thumbnail
for enlarged view)

Residential rain barrels collect roof runoff and can provide irrigation water.
Source: LID Center
(click on thumbnail
for enlarged view)