The ScourStop® Transition Mat is a patented bio-technical alternative for standard hard-armor systems. It is made of a somewhat rigid HDPE. Combined with a soft-armor cover along with deep soil earth anchors, the system will protect soil from severe erosion.
This mat offers much better protection than a vegetation mat or riprap. It has been tested in shown to protect against even the highest stress and water acceleration. A riprap is a form of loose stone that is used to create a foundation for a breakwater or other structures.
These mats offer a permanent, low maintenance answer with an immediate protection and resistance of high erosion areas such as stormwater, overflow structures, levees, shorelines, and drainage.
How ScourStop® Transition Mats Conform to Various Property Values:
In order to withstand the forces of water flow, transition mats must be able to anchor deeply into the soil. ScourStop's bullet anchors are perfectly designed for resistance and strength to conform to various topography.
The Bullet Anchor Driver:
You will need a ground rod driver adapter for use in an electric demolition or rotary hammer to drive the ScourStop Bullet Anchor Drivers. In order to use a hammer of this size will require an SDS MAX ground rod driver. This is standard for many hammer brands. The .75 SDS MAX ground rod driver works with the Bullet Anchor Driver. Whether you purchase or rent an electric demotion hammer, get the largest size possible which is the SDS MAX driver. Demolition or rotary hammers will improve productivity vs a slide hammer. It is advisable to use 2 Bullet Anchor Drivers for each hammer.
For Sediment Control:
Temporary or permanent energy dissipators will prevent erosion and turbulence where there are stormwater pipes or ditch discharges. Dissipators are manufactured to provide protection in downstream areas from erosion. They will reduce the acceleration of water bringing it to an acceptable level. This is often known as Scour Protection or Outlet Protection and commonly used for concrete aprons, riprap-lined or settling basins. These dissipators intercept flow from pipes and ditches and neutralize or deflects the concentrated erosive forces. They will protect soil from high acceleration and turbulence which would otherwise cause for serious erosion.
These structures are constructed with apron linings made from riprap, concrete, turf reinforcement mats, or other materials. There are also certain kinds of basins such as settling basins that can also serve as energy dissipators. Many techniques are very effective, are inexpensive, and very easy to install. Energy dissipators must be designed precisely, based on the hydraulic force of concentrated flows coming from the pipes or ditches. Dissipators that are located at pipe or ditch outlets are good for unpaved areas where erosion is likely to take place.
Dissipators are usually found in areas that have a high concentration of water flow that is present at channel banks, around unstable slopes or along upslopes that are not protected from erosion. They are often found along culverts, drains, ponds, pipe slope drains, ditches, etc. They are also located where runoff is transported naturally or man-made drainage areas such as streams, wetlands, and lakes.
The most popular uses are riprap aprons around culvert outlets, for ditches that have turn reinforcement mats and basins that are developed to either accept or remove water.
What To Consider When Selecting Energy Dissipators:
• The level of difficulty involved to remove trapped sediment caused by the dissipator and not have to
remove the structure.
• Riprap outlets with accelerated flows that will require frequent maintenance.
• They may not be pleasing to look at.
Permit applicability Section III.C.3 of the 2013 MPCA Construction Stormwater General Permit:
The following are paraphrased -
This requires energy dissipation at an outlet of temporary and wet sedimentation basis Section IV.B.3 states that for allowance there must be erosion controls and acceleration dissipation devices such as dams, traps for sediment, riprap at outlets, any outlet to offer water flow to the minimal erosion on channels and their embankments., the banks of streams, and along slopes.
Section III.C.3 also states that a pipe outlet must be provided with either a temporary or permanent dissipation device within 24-hours after being connected to surface water.
Section IV.B.6 requires the use of acceleration dissipation devices when necessary to prevent erosion when sending stormwater to vegetated areas.
• There must be proper protection from erosion when discharging sediment basins.
• Discharge must disperse over natural rock riprap, sandbags, plastic sheeting, and other acceptable
Properly installed permanent or temporary dissipators are very good for preventing channel bank scour, slope water erosion, and the force of moving water to a plunge pool causing even more erosion. Softer rock will erode faster and cut or wear away at the base of the water.
There should be an analysis, evaluation, and review of the location and level of concentrated water flows associated with culverts, ditches, and channel discharges in order to understand where erosion will likely take place. The outlets of culverts are common places for needed dissipators along with areas with ditch discharge to terraces or slopes that are not protected against erosive levels of water flows.
In areas of high acceleration, the best economical solution would be an apron. An impact basin or stilling basin is probably even more appropriate. These structures should dissipate energy from high levels of acceleration to an acceptable level before sending it to an outlet channel. Dissipator designs and installation instructions should be included in the construction installation plans for ditches, channels, and pipes. Culverts can be installed with a riprap apron and discharging channels in ditches can be produced with turf reinforcement matting or other features for high acceleration of discharge in ditches along the banks of larger channels.
Important Considerations For Large Projects:
Minimize the number and force of concentrated flows during clearing and grading as much as possible.
You must install permanent drainage features, such as stabilized ditches, channels, vegetated channel buffers, etc. as soon as possible, especially since installing, maintaining, or stabilizing temporary drainage infrastructure can be time-consuming and expensive.
Incorporating these two approaches can reduce your costs and increase the efficiency of erosion and sediment control at the site.
Because of their closeness to the surface water, many energy dissipators are placed in areas that are subject to state, local, or federal permits. For instance, if they are placed within the waters of the United States, you need a permit from the U.S. Army Corps of Engineers. This is under Section 404 of the Clean Water Act and water quality certification is under Section 401 of the Clean Water Act.
The Construction & Design Of Temporary Dissipators:
On construction sites, most dissipators include riprap aprons that are created for short-term operation for controlling erosion. This period of time is usually under one year. Rule of thumb, these temporary devices should be removed as soon as the surrounding drainage area is stable. Designing of permanent dissipators is usually decided through estimates of erosion force and what their desired appearance will be at the location. For instance, riprap aprons might be appropriate for highways and industrial areas or concrete for culverts but in residential or commercial areas it might require something softer such as turf reinforcement mats that appear as vegetation.
Some dissipators are different in design depending on how they will be used:
Culvert or ditch features
Flow depth or velocity
The design is also chosen by the approach for spreading out the outlet flow, deflecting, absorbing or flow paths to reduce the force of erosion.
If designed correctly, a riprap can be used for several applications such as deflecting water, spreading out the flow, and for movement by using the right size of rocks.`
Other approaches for energy dissipation can be found in the Federal Highway Administration's HEC-14.
For additional information on the Scourstop product see the official Hanes website