A trench is a deep, narrow excavation designed to quickly move, hide, or contain water (often utilizing pipes or gravel). A swale is a broad, shallow, vegetated channel designed to slow down surface water and allow it to naturally soak into the ground.
What is a Swale? 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.
Types of Trenches
Disadvantages of Swales
As a shallow surface feature, a swale requires sufficient space so retrofit opportunities can be limited in narrow urban streets. Biodiverse swales with established wetland planting (such as sedges and Iris) are less suitable for areas with frequent high flows.
A swale is a low, often marshy, or damp tract of land. Depending on its specific use, exact synonyms range from marsh, wetland, trough, and gully.
While both are channels in the landscape used to manage stormwater, a swale is not the same as a ditch. The main difference lies in their primary function and construction.
Common Problems with Swales
Stone is the best material for rushing water. Line the swale with landscape fabric, fill it with inexpensive gravel or crushed concrete and top it off with a few inches of attractive stone. Place larger stones along the sides to hold soil in place.
Wet swales may not be appropriate for some residential applications, such as frontage lots, because they contain standing water that may attract mosquitoes.
For standard yard drainage and permaculture, swales should be 6 to 18 inches deep. The exact depth depends on your soil, climate, and how much water you need to manage. A common design rule is to make the swale three times as wide as it is deep (e.g., 6 inches deep by 18 inches wide).
The "5-4-3-2-1" rule is a common construction and excavation memory aid used to quickly recall critical OSHA Trenching and Excavation Safety standards. It dictates the mandatory requirements for entering and maintaining a safe trench environment.
Soldiers in the trenches used basic pit latrines (dubbed "the bog") dug into the ground behind the front line, or portable buckets—nicknamed "thunderboxes"—placed in designated alcoves. A designated soldier (the "shit wallah") was responsible for emptying these buckets into deeper pits further away each night.
Trenches 5 feet (1.5 meters) deep or greater require a protective system unless the excavation is made entirely in stable rock. If less than 5 feet deep, a competent person may determine that a protective system is not required.
A swale looks like a shallow, wide, and gently sloped ditch or trench. Often following the natural contour of a landscape, a well-designed swale resembles a dry creek bed.
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.
To dig a swale, mark a level contour line or a gentle downward slope across your landscape. Dig a wide, shallow trench (6 to 12 inches deep), and pile the excavated soil on the downhill edge to create a raised, fertile ridge (berm). This structure slows water runoff and encourages deep ground hydration.
Iceland is the only country in the world completely free of mosquitoes. (Antarctica is also mosquito-free, but it is a continent rather than a country.)
Mosquitoes rely heavily on smell to locate humans. They strongly dislike the intense aromas of citronella, lemongrass, lemon eucalyptus, lavender, and peppermint. These scents mask human carbon dioxide and confuse the mosquito's sensory receptors.
Using mothballs outside is illegal because they are classified as restricted-use pesticides, and the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) dictates that using them outside of sealed, airtight containers violates their approved EPA label. Outdoor use releases toxic, cancer-causing fumes, contaminates soil and water, and poses severe poisoning risks to children, pets, and wildlife.
Swales can be lined with decorative materials like river rock, pea gravel, and boulders, and can include vegetation or even landscape lighting for added visual impact.
Gravel drain rock is recommended with a cover of decorative surface rock (commonly rounded river rock or cobble). The general specification is one inch washed drain rock. Surface rock should be washed and free of fines that may wash down into the gravel drain rock.
French drains are a low-cost option for dealing with surface water. These systems consist of a trench which houses a perforated PVC pipe. The pipe is secured in a mesh sock to keep dirt out, that is covered with gravel.
As the fall rains intensify and the seasons shift, one surprising tip is getting renewed attention: pouring vinegar down your drains to help prevent clogs.
Pouring salt down your drain at night is a popular DIY plumbing trick used for routine maintenance. The goal is to take advantage of the salt's coarse texture and natural moisture-absorbing properties.
In plumbing, the "135-degree rule" is a code standard that dictates how much a horizontal drain pipe can bend or change direction. It limits the total cumulative angle of pipe fittings before a system requires an access point (cleanout) or must be vented, ensuring proper flow and preventing chronic clogs.