1. Infiltration: LID techniques promote the infiltration of stormwater into the ground, reducing runoff and preventing it from overwhelming waterways. This is achieved by using permeable surfaces, such as porous pavement, vegetated swales, and rain gardens, which allow water to soak into the soil. Infiltration helps replenish groundwater supplies and reduce the strain on conventional sewer systems.
2. Detention: LID also incorporates detention practices to temporarily store stormwater and release it slowly over time. This can be done using detention basins, ponds, and wetlands. Detention helps reduce peak flow rates and prevent flooding downstream, while also allowing for the natural settling of pollutants and sediment.
3. Filtration: LID techniques provide opportunities for stormwater to be filtered through vegetation, soil, and other natural materials. This helps remove pollutants, such as suspended solids, nutrients, heavy metals, and bacteria, before they reach receiving waters. Filtration improves water quality and protects aquatic ecosystems.
4. Evapotranspiration: LID encourages evapotranspiration, the process by which plants absorb and release water through their leaves. This helps reduce the volume of stormwater runoff and cool the surrounding microclimate.
5. Disconnection: LID disconnects impervious surfaces, such as rooftops and driveways, from conventional storm sewer systems. By redirecting stormwater to LID practices, it reduces the amount of runoff entering these systems and helps prevent combined sewer overflows (CSOs) and sanitary sewer overflows (SSOs).
By implementing LID techniques, communities can better manage stormwater runoff, mitigate the impacts of urbanization on water resources, and create healthier and more sustainable environments. LID practices not only improve water quality and reduce flooding but also enhance the aesthetic and ecological value of urban landscapes.
