What is the difference between bioswale and bioretention?

Bioswales, which are wet or dry swales made out of grass, rocks, and other types of vegetation, must be sloped to move water through the system in an efficient manner. Bioretention ponds are depressed vegetated areas that capture and store stormwater runoff and can work in combination with bioswales.

What are bio basins?

A bioretention system consists of a soil bed planted with suitable non-invasive (preferably native) vegetation. In general, a bioretention basin has a flat bottom while a bioretention swale may have sloping bottom. Runoff storage depths above the soil bed surface are typically shallow.

What is a vegetated swale?

Vegetated swales are an important Low Impact Development technique used to convey stormwater runoff. The vegetation in swales, usually thick grass, helps to trap pollutants (suspended solids and trace metals), and reduce the velocity of stormwater runoff; stormwater also percolates through the natural substrate.

What is a bioretention swale?

Bioretention swales are shallow, vegetated, landscaped depressions with sloped sides. They are designed to capture, treat and infiltrate stormwater runoff as it moves downstream.

What is the importance of a micro-Bioretention?

They are designed to filter stormwater runoff and im- prove water quality. Micro-Bioretention Areas (see pg. 4 for photo) are usually planted with native plants and have three layers: mulch, a filter bed mixture of sand, soil and or- ganic matter, and a stone layer.

Where do I put bioswale?

Ensure that the location you select is at least 6 feet from your house and 5 feet from your property line. This will help you avoid any water damage in case of future drainage issues. Dig a shallow depression that is 6 inches deep and as long and wide as you want your bioswales to be.

What is the purpose of a bioretention basin?

Bioretention basins are landscaped depressions or shallow basins used to slow and treat on-site stormwater runoff. Stormwater is directed to the basin and then percolates through the system where it is treated by a number of physical, chemical and biological processes.

How do you size a bioretention basin?

The minimum size for any bioretention facility should be 10 feet wide (perpendicular to incoming sheet flow direction) and 15 feet long. The depth of the facility’s planting soil (reference Figure 11.1) should be approximately 30 inches, or the diameter of the largest plant root ball plus 4 inches.

How do you maintain a swale?

1. SUGGESTED MAINTENANCE ACTIONS.
2. MONTHLY.
3. • Inspect your swale during and after storms to make sure that rainwa- ter has drained and there is no erosion. •
4. SEASONALLY.
5. • Mow grass no shorter than 3 to 6 inches. Remove and compost all grass clippings.
6. AS NEEDED.
7. • Reseed bare areas to avoid erosion.
8. DO NOT:

How do you size a swale?

When constructing a swale with known side slopes, the width of the swale can be defined in terms of the depth. For example, 3:1 side slopes on a swale indicates that for every 1 foot of depth, each side slope will be 3 feet wide, for a total swale width of 6 feet.

How effective are Bioswales?

According to the American Society of Landscape Architects (ASLA), a 4-meter bioswale can reduce about 25% the of total rainfall runoff. The effectiveness of bioswales extends to their ability to filter stormwater naturally.

What is the difference between a detention pond and a retention pond?

The Difference Between Detention and Retention Ponds A detention, or dry, pond has an orifice level at the bottom of the basin and does not have a permanent pool of water. A retention basin or pond has a riser and orifice at a higher point and therefore retains a permanent pool of water.

How are bioswales used to treat stormwater?

Drainage time of bioswales Linear bioretention cell designed to convey, treat and attenuate stormwater runoff. The engineered filter media soil mixture and vegetation slows the runoff water to allow sedimentation, filtration through the root zone, evapotranspiration, and infiltration into the underlying native soil.

What should the infiltration rate of a swale be?

Swales constructed with an underlying 12 to 24 inch aggregate layer provide significant volume reduction and reduce the stormwater conveyance rate. The permeable soil media should have a minimum infiltration rate of 0.5 inches per hour and contain a high level of organic material to enhance pollutant removal.

How are engineered filter media used in bioswales?

The engineered filter media soil mixture and vegetation slows the runoff water to allow sedimentation, filtration through the root zone, evapotranspiration, and infiltration into the underlying native soil. A shallow excavated surface depression containing prepared filter media, mulch, and planted with selected vegetation.

How does a bioswales lid protect the soil?

A bioretention BMP featuring an impermeable liner and underdrain that prevents infiltration of runoff into the underlying native soil; provides sedimentation and filtration of urban runoff as it passes through the mulch layer, engineered filter media and vegetation root zone.