Infiltration Trenches and Infiltration Basins

Infiltration trenches and infiltration basins are specifically designed and constructed as surface or subsurface areas of storage, with a permeable bottom and sides to promote infiltration of the stored water into the surrounding soils. The primary mechanism in infiltration systems is, as its name implies, infiltration of stored stormwater into the surrounding soils. Successful infiltration will lead to groundwater recharge and reduction of surface runoff. Surface infiltration basins are designed using similar criteria as retention ponds but add the dynamic infiltration capability. Pretreatment removal of sediment is critical for proper long-term operation of infiltration facilities. The function of an infiltration basin is straightforward: it needs to effectively infiltrate stored stormwater. Inspection of infiltration basins needs to confirm this function. The inspection can consist of observing the water levels in the basin for few days after a water-quality storm and documenting that the water level is adequately falling.