A swale is like a ditch, but it's broad and shallow, and usually covered or lined with turfgrass or other vegetation.
Swales are located in areas which can fully drain and are typically dry. Swales can also be headlands or access tracks that are not used regularly for farm traffic. Drains are located on flat or backwatered locations which results in them holding water.
Although a swale and drainage ditch may look the same, a ditch is designed solely for conveying drainage water, with no water quality treatment intended. A swale, on the other hand, is typically a regulated and engineered SCM that is credited for treating and conveying stormwater.
A swale is a shady spot, or a sunken or marshy place. In US usage in particular, it is a shallow channel with gently sloping sides. Such a swale may be either natural or human-made. Artificial swales are often infiltration basins, designed to manage water runoff, filter pollutants, and increase rainwater infiltration.
For a relatively flat yard, a swale will generally drop 1 inch for every 10 feet of length. If your yard is flat for 60 feet, and then drops several feet to the street, a swale starting in the back yard would begin at a depth of two inches and be 8 inches deep at the point where it reached the drop to the street.
When should you not use a contour swale? Contour swales are not the tool you want to choose when the issue you are facing is too much water and oversaturation on your site. They are also best used on slopes that are 3:1 or less because that keeps your berm from getting too steep, causing further erosion.
Affordable: The average cost to build a swale drainage ranges from $0.50 to $1 per square foot or $5 to $15 per linear square foot, making this drain type one of the most affordable to install. Aesthetic appearance: Due to their inconspicuous appearance, swale drains can easily fit into your landscaping plans.
Negative environmental impacts of vegetated swales may include: Leaching from swale vegetation may increase the presence of trace metals and nutrients in the runoff. Infiltration through the swale may carry pollutants into local groundwater.
Reseed bare areas to avoid erosion. Be sure to water during the initial establishment period. Inspect and maintain or repair components. After rainfall, check the swale to ensure the water does not pond longer than 2 or 3 days after a rain storm.
Like a trench drain, a swale is a surface water drainage device. However, it's a lot more subtle in terms of its appearance in the landscape. A swale is like a ditch, but it's broad and shallow, and usually covered or lined with turfgrass or other vegetation.
The primary function is to convey stormwater runoff and there is minimal water quality benefit; however, rock lined and vegetated swales may decrease the velocity of water and facilitate some infiltration. Vegetated swales may have the added benefit of filtering stormwater as it flows through the swale.
The uphill side of the house must have a drainage waterway (swale) to direct the water around the house. This drainage swale should be at least ten feet from the house and sloped to convey accumulated water away from the dwelling efficiently, and into a proper outlet.
Landscaping Drainage Swales: Turfstone Pavers and Walkways
You can fill the spaces with gravel or plant grass or other ground cover. You'll combat erosion and water as well as filtering water as it soaks down into the ground.
Where drainage is slower still, replace soil with 60 percent screened sand and 40 percent compost. If the swale itself can't be made big enough to handle all the water, consider excavating another 6 to 8 inches, lining the trench with filter fabric, laying perforated pipe, then covering it with round ¾-inch gravel.
Gravel trenches are narrow, stone-filled channels situated over well-draining soil that utilize the empty spaces between stones to act as a temporary reservoir for stormwater as it soaks into the surrounding soil.
A shallow constructed channel, often grass-lined, which is used as an alternative to curb and channel, or as a pretreatment to other measures. Swales are generally characterized by a broad top width to depth ratio and gentle grades. Vegetated, open channels designed to convey, treat and attenuate runoff.
Geometry/Slopes
While the bottom of the swale is at least 2-feet wide, the treatment area is at least 6-feet wide and no more than ½ foot in depth.
This will change the taste of your drinking water, as will any likely bacterial growth or changes in the mineral content over time. Bacteria will grow more in warm water, especially if any chlorine has evaporated. Therefore it's best to discard any warm water that's been left open for more than 12 hours.
Every 5-10 years (as needed) • If swale loses infiltration capacity, replace the bio-engineered planting soil and vegetation. Poor grass health Your grass may be the wrong type for your shade and moisture conditions or it may be smothered by weeds. Remove dead or diseased grass and plant new vegeta- tion as needed.
The most frequently cited maintenance concern for wet swales is that they provide a breeding ground for mosquitoes.
A drainage swale costs $0.50 to $1.00 per square foot or $5 to $15 per linear foot, depending on the size, depth, and grading required.
Problem: Over time, swales can experience erosion, leading to sediment buildup within the swale itself or downstream. Solution: Regularly inspect and maintain your swales by filling eroded areas, stabilizing slopes with vegetation, and removing accumulated sediment to ensure proper drainage.
A grassed swale is a graded and engineered landscape feature appearing as a linear, shallow, open channel with trapezoidal or parabolic shape. The swale is vegetated with flood tolerant, erosion resistant plants.
If you have a drainage swale on your property, it's your responsibility to maintain it so that it functions properly. Improperly maintained drainage swales interferes with proper drainage flows that can result in property damage caused by slope failure, erosion, or excess storm-water runoff.
Place rocks, gravel, mulch, and/or plants within the swale. Test the effectiveness of the swale by running water through your system. A swale is a V or U-shaped depression that helps move water like a dry creek.