Roofs, parking lots and roads shed large amounts of storm water in a short time. Storage areas and bare paddocks add to soil erosion and polluted runoff when fast-moving storm water washes over them. An infiltration basin prevents further erosion and pollutants from entering drainage ways, ponds and streams. The basin collects water from drainage pipes or over ground surfaces. It stores the water temporarily until it soaks into the ground.
Place the basin on the downhill side of farm structures. Base the size of this shallow depression on the amount of storm water expected to fill it over a given time. Dig the basin or create berms to form the sides. Pile soil, which may include rock, to form a solid long hill with sloped sides.
Fill the bottom of the basin with gravel or sand and cover with a few inches of topsoil. Plant the basin with perennial plants and shrubs. This helps take up both water and any nutrients or pollutants that enter the basin.
A berm is a wall or mound of dirt that keeps rainwater in a specific area. If area soils do not drain well, add outlet drainage pipes to the gravel layer below. Alternatively, install an overflow dam at the lower end.
These vegetated infiltration basins or rain gardens make attractive landscape gardens for barnyards.