Rain Garden and Bioswale Design

Rain Garden and Bioswale Design

All-Terrain Consulting Ltd. excels at designing a visually appealing and functional rain garden for your property.

A rain garden is defined as a planted depression that allows rainwater run-off from impervious urban areas, like roofs, driveways, walkways, parking lots, and compacted lawn areas, the opportunity to be absorbed. This reduces rain runoff by allowing stormwater to soak into the ground (as opposed to flowing into storm drains and surface water which causes erosion, water pollution, flooding, and diminished groundwater). They can be designed for specific soils and climates. The purpose of a rain garden is to improve water quality in nearby bodies of water. Rain gardens can cut down on the amount of pollution reaching creeks and streams by up to 30%.

Native plants are recommended for rain gardens because they generally do not require fertilizer and are more tolerant of one’s local climate, soil, and water conditions, and attract local wildlife such as native birds. The plants take up excess water flowing into the rain garden. Water filters through soil layers before entering the groundwater system. Root systems enhance infiltration, maintain or even augment soil permeability, provide moisture redistribution, and sustain diverse microbial populations involved in biofiltration. Also, through the process of transpiration, rain garden plants return water vapor to the atmosphere. A more wide-ranging definition covers all the possible elements that can be used to capture, channel, divert, and make the most of the natural rain and snow that falls on a property. The whole garden can become a rain garden, and each component of the whole can become a small-scale rain garden in itself.

All-Terrain Consulting Ltd. can also incorporate bioswales into the design of larger properties or parking areas to treat water run-off prior to it entering into the environment.

Bioswales are defined as being landscape elements designed to remove silt and pollution from surface run-off water. They consist of a swaled drainage with gently sloped sides (less than six percent) and filled with vegetation, compost, and/or riprap. The water's flow path, along with the wide and shallow ditch, is designed to maximize the time water spends in the swale, which aids the trapping of pollutants and silt. Depending upon the amount of land available, a bioswale may have a meandering or almost straight channel alignment. Biological factors also contribute to the breakdown of certain pollutants.

A common application is around parking lots, where substantial vehicle pollution is collected by the asphalt and then flushed down the catch basins by rain. The bioswale, or other type of biofilter, wraps around the parking lot and treats the runoff before releasing it to the environment or storm sewer.

Please call All-Terrain Consulting Ltd. for more information at (778) 230-4174.