Frequently Asked Questions

Bioswales are designed to decrease the rate and quantity at which water runs off from an area.  So, yes they are effective at reducing the risk of flooding but not completely eliminating flooding. 

Most bioswales are hard to spot without knowing that they are present.  Bioswales really look like another ditch or depression but most are landscaped nicely.  Sometimes a sign will be present to prevent damage or mowing of the plants.  Many bioswales look like a really well landscaped dry swale or ditch along parking lots or roads. 

The bioswale is the actual ditch that conveys the water while at the same time allowing a portion of the water to infiltrate into the soil.  The rain garden is an area designed to infiltrate the water into the soil.  Both are very similar and function in the same manner.  Both can have the same plants and soil mix installed. 

A bioswale is an oversized ditch where the bottom portion is filled with soil that allows a portion of the water to absorb or infiltrate into the soil downward.  It helps filter runoff to improve its quality and reduces the amount of stormwater runoff.  The benefit of bioswales is that they still convey the water from a road, building, or other impervious surface to a stream or lake but at the same time it can treat a portion of the water to improve its quality.  Bioswales are typically planted or sodded to prevent erosion within the channel as well. 

There are many soil and sand producers/suppliers across the US.  Companies like River Sand, Inc. can blend soil for bioswales to meet specifications for projects.  Typically, they have their own soil lab or send the bioswale soil mix for testing to ensure it meets the requirements for a project.  Delivery is typically done in dump trucks as loose, bulk soil.  Be sure to have a proper location to store the soil mix so that no contaminates (other dirt or rocks) are mixed with the soil prior to installation (if it is not being dumped directly into the bioswale).