As an option, you might want to add plants that love water alongside the drainage trench to create a beautiful element for your landscape. Consult a local nursery in your area to get a better idea for what plants will work best for your climate.
Planning The Ditch
With proper planning, your ditch should be positioned so water will travel downhill into the side of the ditch. Once the water enters the drainage ditch, it should flow downhill. Therefore, the drainage ditch must be angled across slopes to catch water and carry it away from problematic areas.
You need to plan out your drainage trench to ensure it catches water flowing downhill or for drain areas of standing water.
A drainage trench must slope down at least 1-inch (2.5 cm) for every 10 feet (3 meters) to drain properly. To capture water and drain downhill the right way, your ditch may need to contour.
Road-side drainage ditch with large stone
For a natural-looking element, add more curves and bends. By making it look more natural however, more liner will be used to compensate for the bends. Additionally, additional care will be required when overlapping the liner pieces to ensure that water cannot flow around the overlapped pieces. You should measure the slope of your yard to ensure you have good drainage.
Excavating Your Trench
The rock drain should be wider than it is deep which is in complete opposition to a French drain that is narrow and deep. Dig the trench to 18-inches in-depth (45 cm) and 36-inches in width (50 cm). This will prevent erosion, washouts, and a flooded drainage ditch.
Dig your drainage ditch 18 inches deep. A rock drainage ditch should be twice as wide as deep. In this case, 36 inches. If you want a natural stream bed, analyze your drainage trench and widen it in various places, especially at bends.
Depending on the look you want to achieve, the drainage ditch could have gently sloping sides or straight sides. Keep in mind that steep sides are more susceptible to erosion and may have to be reinforced with a rock border.
The Ditch Liner
Once the drainage ditch is completed, line it with waterproof ditch liner. The liner will prevent erosion and stop weeds from coming up from the bottom of the trench. The liner will hold back gravel and keep it from mixing with dirt so the trench will continually drain properly over time.
Add The Gravel
Pour an 8-inch deep (20 cm) layer of gravel or rock on top of the ditch liner in your drainage ditch. For best results, use large rocks such as no. 3 crushed stone which will range from ¼ to 2 inches in size. As a substitute, 1-1/4"-2" stone will do quite well.
Pour 8 inches of gravel into the bottom of the drainage trench, on top of the liner.
Avoid using small gravel, like pea gravel. Small gravel will compact and prevent water from flowing through. In turn, it will lead to a flooded drain that will not offer any benefits. Larger rocks will allow the water to seep and enter the soil.
Top Off With Stones or River Rocks
Top your gravel layer with 2 inches of rocks, additional gravel, or field stones. smooth river rocks to create a creek bed appearance.
Even though there are many different materials you can use as a finishing layer, use medium-sized rocks to advance good drainage. Avoid using sand or other materials that could prevent proper drainage or will allow weeds to take root.
Add A Border Or Use Plants
To complete your drainage ditch, you can leave it as is or use field stones and rocks alongside. Because the ground around the ditch will be moist, you might want to consider planting water-loving plants like lilies, irises, or horsetail rush.
For a rocky look, place some decorative field stones or large rocks alongside your drainage ditch. Keep in mind, that because your drainage trench is performing properly, does not mean it has to be totally unattractive. You can choose the look you want and turn it into a landscaping center of attention.
What Is The Best Size Rock For Drainage?
Whether medium or large-sized rocks, both offer the best drainage for a trench or ditch.
Always consider:
- Use medium to large-sized rocks
- Choose an angular rock that will not cause compaction.
- Do not use small rocks, round gravel, or sand. They drain very poorly and are susceptible to sliding.
- No. 3 stone or 1" to-2" gravel
- Large rocks, river stones, fieldstones.
