Category:Level 2 - Technical and specific topic information/infiltration

Category:Level 2 - Technical and specific topic information/infiltration

Schematic showing an infiltration basin, which is one of several stormwater control practices designed to infiltrate stormwater runoff. Infiltration practices capture stormwater runoff and allow it to infiltrate into the underlying soil. Pollutant removal occurs through a variety of mechanisms, including adsorption, absorption, plant uptake, and degradation. Note that inflow into the practice has undergone pretreatment and that once the practice is filled, runoff bypasses the practice rather than entering it.

Infiltration main page

Main page for infiltration practices

Stormwater infiltration is the process by which rainfall and stormwater runoff flows into and through the subsurface soil. Stormwater infiltration occurs when rainfall lands on pervious surfaces, when runoff flows across pervious surfaces, and when runoff is collected and directed to a stormwater infiltration Best Management Practice (BMP).

Current stormwater management policies encourage, when appropriate, maximizing the infiltration of stormwater to reduce the volume of runoff discharging to surface waters. In addition to reducing runoff volume, stormwater infiltration helps reduce stormwater pollutant loading to surface waters. Many factors influence the rate and volume of stormwater infiltration, including soil and rainfall characteristics. Once stormwater infiltrates into the soil, it has the potential to enter the groundwater, become part of the subsurface flow, or be taken up by vegetation.

For the purposes of this manual, infiltration BMPs are considered BMPs without underdrains.

This page provides links to pages that address topics related to infiltration of stormwater, such as constraints on infiltration and determining infiltration rates at sites.