D4RUNOFF NBS Library: https://d4runoff.eu/resources/

Dry wells are excavated pits (usually small), backfilled with aggregate, and used to infiltrate uncontaminated runoff from roofs. Dry wells are constructed to reduce stormwater runoff volumes through increased groundwater recharge and can be used as retrofits of highly urbanized areas. Dry wells are stormwater infiltration devices typically constructed of a vertical pipe that extends deep into the subsurface without contacting the groundwater table. They are characterized as infiltration facilities that are deeper than they are wide. Perforations are located along the length of the pipe and/or at the bottom to permit stormwater to flow from various parts of the well into the surrounding soils.