Aninfiltration basin (orrecharge basin) is a form of engineered sump[1] orpercolation pond[2] that is used to managestormwaterrunoff, preventflooding and downstreamerosion, and improvewater quality in an adjacentriver,stream,lake orbay. It is essentially a shallow artificial pond that is designed toinfiltrate stormwater through permeable soils into thegroundwateraquifer. Infiltration basins do not release water except by infiltration, evaporation or emergency overflow during flood conditions.[3][4][5]
It is distinguished from adetention basin, sometimes called adry pond, which is designed to discharge to a downstream water body (although it may incidentally infiltrate some of its volume to groundwater); and from aretention basin, which is designed to include a permanent pool of water.
Infiltration basins must be carefully designed to infiltrate the soil on a given site at a rate that will not cause flooding. They may be less effective in areas with:
High groundwater levels, close to the infiltrating surface
At some sites infiltration basins have worked effectively where the installation also includes an extendeddetention basin as a pretreatment stage, to remove sediment.[7] The basins may fail where they cannot be frequently maintained, and their use is discouraged in some areas of theUnited States. For example, they are not recommended for use in the U.S. state ofGeorgia, which has many areas with high clay soil content, unless soil on the particular site is modified ("engineered soil") during construction, to improve the infiltration characteristics.[8]