Straw wattles are bundles of straw snuggled together by a mesh net. These can also be known as straw worms or fiber rolls. The inner straw is completely weed free and clean. The outer net (top layer) is constructed from a UV-resistant material that is designed to biodegrade. The wattles slow the water down, collect and filter sediments and also act as a buffer to the soil as the water flows through.
How Do Straw Wattles Work?
While straw wattles may appear basic, this design serves multiple functions that are critical for erosion control. They slow water, trap sediment and help to condition the soil.
1. Reducing Water Speed
Straw wattles slow water flow over the soil. Reduced flow of water means less erosion, because the water is not as powerful and will not wash the topsoil away.
2. Trapping Sediment
As water flows through a straw wattle, it deposits small soil particles on the upstream side. The wattle catches this sediment, which otherwise would be washed into and pollute nearby water.
3. Helping Soil Retain Moisture
Straw within the wattle retains water and gradually returns to the soil. This allows the soil to retain moisture and encourages the growth of new plants. Straw adds nutrients back into the soil as it breaks down.
What Are the Main Uses?
Straw wattles are used in many different places for so many different reasons. Their versatility allows them to be used in both small landscaping tasks and larger construction projects.
At Construction Sites
The soil is usually left exposed when under construction and is easy to wash away. Straw wattles serve as sediment barriers for construction sites. They are a critical component of a stormwater management plan.
On Slopes and Banks
Straw wattles work well along slopes or stream bank areas. They act as check dams that slow down the water and prevent the soil from washing away. This allows them to be effectively used to stabilize hillsides, preserving a natural landscape.
Around Water Drains
Installed around storm drains or inlets, straw wattles help keep sediment from clogging the system. They help filter the water and keep drains from clogging and flooding.
In Restoration Projects
Straw wattles work well for projects designed to bring vegetation back to eroded land. They hold the soil in place long enough for seeds to take hold. As the native plants grow and the wattles break down, they become a source of organic matter fed into the soil, further improving soil quality.
Installation Guidelines
An important thing to remember is proper installation if you want straw wattles to do their job effectively. Doing a few simple things makes them stay put and last longer.
1. Planning the Installation
Check out the area to see where erosion will most likely happen before placing the straw wattles. Ideally, it’s best to put the wattles along the contour lines of a slope where the water tends to flow.
2. Digging Trenches
Dig a small trench in the area where it will be installed. The trench needs to be shallow (typically 2 to 6 inches deep) and wide enough for the complete diameter of the straw wattle. This also helps keep the wattle in place.
3. Setting the Wattles
The straw wattle is then laid into the trench, resting tightly against the soil. The space left after placing the wattle is filled with soil. This backfill secures the wattle well in place.
4. Securing with Stakes
Wooden or biodegradable stakes are driven through the wattles every 3 to 4 feet along the length to prevent movement. The stakes extend a few inches above the wattle, so they remain firmly in place, even with heavy rain.
5. Overlapping for Better Protection
When multiple straw wattles are needed, they should be staggered or butted tightly against each other. This way, there are no opportunities for water to pass through without being slowed.
Maintenance and Care
A little upkeep is all that’s needed to keep straw wattles doing their job. Taking a look at them after a rain and clearing out deposits is an easy but important step.
- Regular Inspections: Once installed, the wattles need to be regularly inspected, especially following heavy rainfall. Check for tears in the net or any gaps, or even monitor how they have moved.
- Dealing with Sediment: As the time goes on sediment will deposit in front of the wattles. Lightly packing some of the soil back around the sediment keeps the sediment in place, so that the wattle can keep on working.
- Encouraging Plant Growth: Straw wattles gradually decompose and plants begin to grow. The soil is further stabilised by this. If the area is still bare, may need to replant or hydroseed.
- Replacement: Straw wattles typically last 12 to 24 months. When they have completely fallen apart or are no longer doing their job, or if more long-lasting protection is desired, install new wattles.
Benefits of Using Straw Wattles
Straw wattles have become quite popular for many reasons. They are cheap, simple, green and valuable in many environments.
Cost Savings
Straw wattles are much cheaper in erosion control than more sophisticated solutions, such as concrete barriers or riprap. Users should buy it as they are affordable and can be used in the garden, on the business site, and in the construction projects.
Environmental Advantages
Straw wattles are made from natural and biodegradable materials, so leave no harmful waste. This will eventually decay on its own, adding nutrients to the soil and helping create a more sustainable and healthy ecosystem.
Simple and Quick Installation
No heavy machinery is necessary to install straw wattles. They can be erected in no time by anyone with simple tools like shovels and stakes. Since installation is so straightforward, it can save time and labor costs.
Versatility Across Many Applications
Straw wattles can be used in various locations, such as construction sites, slopes, and water drainage systems. Their adaptability means they do great on a variety of terrain and weather, and are a good option for erosion control.
Improved Water Management
Straw wattles enhance overall water management by slowing down runoff and aiding in soil absorption of water. There is also a significant advantage in rural areas where water conservation and filtration are essential.
Conclusion
Straw wattles are a simple, natural way to manage erosion and control stormwater runoff!. They slow down water flow, capture sediment and help soil hold moisture while decomposing naturally to enrich it. From construction sites and slopes to drainage areas and restoration projects, their low cost, ease of installation, and versatility contribute to their widespread popularity.