Sediment Barrier
Ninety7 wattles used as downslope water interrupters slow stormwater, and filter and trap sediment before it flows into waterways. Proper installation is essential to ensure proper performance.
The Ninety7 wattles can be left in place or removed depending on the application (temporary or permanent installation)
Removal of Ninety7 wattles used in permanent applications can result in greater soil disturbance.
Ninety7 wattles used as downslope water interrupters slow stormwater, and filter and trap sediment before it flows into waterways. Proper installation is essential to ensure proper performance.
The Ninety7 wattles can be left in place or removed depending on the application (temporary or permanent installation)
Removal of Ninety7 wattles used in permanent applications can result in greater soil disturbance.
Installation Guidelines
The following should be considered when installing Ninety7 wattles:
The following should be considered when installing Ninety7 wattles:
- Ground preparation
- Proper spacing between the wattles
- Proper staking
Ground Preparation
To ensure proper contact with the ground, remove any rocks and debris from the desired area of installation and smooth it as much as possible.
To ensure proper contact with the ground, remove any rocks and debris from the desired area of installation and smooth it as much as possible.
Downslope Spacing
Slope gradient and soil type should determine the vertical spacing of Ninety7 wattles for slope installations.
Slope gradient and soil type should determine the vertical spacing of Ninety7 wattles for slope installations.
- For gentle slopes of <20%, the vertical spacing should be fifty feet apart.
- For moderate slopes of 20% to 35%, vertical spacing should be thirty feet apart.
- For steep slopes of 35% to 45%, vertical spacing should be twenty feet apart.
- For soft, loamy soils, rows can be closer together.
- For hard, rocky soils, rows can be further apart.
- Ninety7 wattles are not recommended for use on slopes above 45%.
Staking
To ensure intimate contact with the ground, Ninety7 wattles are anchored with wooden stakes or sandbags, or a combination of the two.
To ensure intimate contact with the ground, Ninety7 wattles are anchored with wooden stakes or sandbags, or a combination of the two.
Method
Proper installation and maintenance of the Ninety7 wattle help capture sediment on the upslope side.
Proper installation and maintenance of the Ninety7 wattle help capture sediment on the upslope side.
- Prepare the area of installation per project specifications.
- Start installing Ninety7 wattles from the bottom of the slope and work up.
- Firmly place the Ninety7 wattle in the desired area, perpendicular to flow with ends curled slightly upstream to prevent higher velocity water from going around the ends.
- Drive the wooden stakes securely through the handles and into the ground until 2”- 3” of stakes remain exposed. To avoid compromising the integrity of the Ninety7 wattle, do not pierce its body.
- If more than one Ninety7 wattle is placed in a row, a 12” overlap should be allowed. Ninety7 wattles should not be abutted.
Maintenance
- Inspect the Ninety7 wattles as required by project specifications and following rainfall events. Repair or replace split, torn, unraveling, or slumping wattles.
- Maintain the Ninety7 wattles to provide an adequate sediment holding capacity. Sediment should be periodically removed and incorporated in the project to blend in with adjacent ground when it accumulates to three-quarters (3/4) of the Ninety7 wattles height.
Removal after Temporary Use
- Sediment barrier installations of Ninety7 wattles should only be removed when up gradient areas are stabilized.
- Collect and dispose of the accumulated sediment.
- Fill and compact depressions and any other ground disturbance.
- Manufacturer encourages recycling the used Ninety7 wattles to make mulch.
