SmartDitch Ditch Liningy System FAQs

Is there a concern with freeze/thaw with SmartDitch?

Freeze-thaw may cause some slight shifting but concrete-lined or riprap channels would be subject to the
same effects. The flexibility of the HDPE allows the product to better absorb shifts in the earth caused by
freeze-thaw cycles. If some noticeable slack appears in the anchors, the cables can easily be tightened.
The anchors act to hold the SmartDitch in place and keep good ground contact especially when the
ditch is empty. When flowing full the weight of the water increases the frictional force between the product
and soil that resists slipping.

Is SmartDitch easy to maintain?

Under normal weather and operational conditions, SmartDitch is easy to maintain. Like any other
channel or ditch, routine inspections are recommended to make sure there is no erosion along the
SmartDitch-Soil interface that would potentially cause undermining. The anchors should be checked for any
slack and tightened as needed.

Is there a grade required for Smart Ditch to perform?

SmartDitch will flow at any slope. However, since SmartDitch is a flexible lining system, care should be
taken to maintain a positive slope when excavating. A minimum slope of 1.5% is recommended to prevent
ponding due to the difficulty of excavating a trench at a slope less than 1.5%. However, SmartDitch will
still function at slopes less than 1.5%

Does SmartDitch have engineering support?

Yes. Penda Corporation's success is due, in large part, to it's outstanding Engineering and Technical support
group. Most questions can answered within 24 hours of your inquiry. SmartDtich can also be custom
engineered to your specific application requirements. Please call 1-866-576-2783 for more information.

Can you recycle SmartDitch?

Yes, SmartDitch is manufactured from HDPE, which is 100% recyclable.

How long does SmartDitch last? What is the estimated useful service life of the product?

SmartDitch is made of HDPE and enhanced with UV inhibitors. Accelerated laboratory testing projects a
minimum lifespan of 20 years.

How big is the SmartDitch radius?

SmartDitch can be installed on the following minimum radius of curvature:
12" Trapezoid – 10 feet
24" Trapezoid – 75 feet
24" Semi–circular – 80 feet

Is there a maximum slope?

The maximum slope of an installation is dependent on soil types and the stability of the slope on

What is the maximum flow capacity?

Flow capacity is dependent on slope. The steeper the slope, the higher the flow capacity. Flow calculations
can be found in the "Appendix" section of the SmartDitch Technical Manual, Section 4.2

How does the product get to my jobsite?

Depending on the scope of the project, the product will either ship directly from our manufacturing facility
in Portage, WI, or through a local stocking distributor.

Are the "Installation Kits" included in the cost of the product?<

Yes, the price includes of all installation kit components.

What materials are used to manufacture SmartDitch?

HDPE (high-density polyethylene) – in an ISO certified facility

How does SmartDitch hold up in different weather climates?

SmartDitch is made of HDPE, which is very durable and extremely resistant to chemicals and corrosion. UV
stabilizers are also included to inhibit the physical and chemical process of UV-induced degradation. The
inherent physical properties of HDPE manufactured SmartDitch will also allow it to perform well in both
hot and cold environments.

Is SmartDitch considered a temporary or permanent product?

SmartDitch is a considered a permanent erosion control product with a projected minimum service-life of 20
years.

How do I anchor the system?

The SmartDitch system is anchored using steel anchors that are driven into the ground with a driving rod
or an impact hammer in tight soils. The cable is pulled tight and held in place with a cable lock.

Are there other colors of SmartDitch available?

Yes. Environmental Green and Desert Tan

Who Manufactures SmartDitch?

North America's # 1 heavy-gauge thermoformer, Penda Corporation. For more information, we suggest you
go to www.pendacorp.com

What if there are slopes where vegetation cannot be established because of climate or unsuitable soil and there is lateral drainage into the SmartDitch?

Use riprap or geotextile fabric. Geotextilse should be either woven or nonwoven polyester, polypropylene,
stabilized nylon, polyethylene, or polyvinylidene chloride with the following physical properties:

Minimum Grab Tensile Strength (ASTM D 4632) 205 lb (900 N)
Minimum Puncture Strength (ASTM D 4833) 80 lb (350 N)
Minimum Apparent Breaking Elongation (ASTM D 4632) 15%
Maximum Apparent Opening Size No. (ASTM D 4751) 30 (600 micrometers)
Minimum Permittivity (ASTM D 4491) 0.12 s-1

Riprap should be sized and carefully placed based on site conditions and expected flows.

Why not just lay down Riprap instead of using the SmartDitch System?

Two reasons. First, you cannot just "lay" down some Riprap in a creek bed or flow channel. It requires a
variety of rock sizes that must be carefully secured and placed to ensure it achieves the desired flow control
results. Second, Riprap does not handle high velocity flows well, and will be displaced over time; creating
maintenance and reapplication issues. The amount of Riprap needed to be laid into a ditch to equal the
same flow capacity the SmartDitch System can handle is staggering.
Results show that a RipRap lined channel requires 2.6 times the cross-sectional flow area to equal the flow
in a SmartDitch System. An additional 1.5 ft.- 3 ft. of over-excavation would also be required to install the
RipRap creating a larger footprint and additional waste soil.
(download the SmartDitch vs. Riprap Product Comparison Chart)

Is there a maximum shear stress for SmartDitch

There is no maximum shear stress in the traditional sense between the water and the HDPE liner?
Theoretically that maximum shear stress would be equivalent to the tensile strength of the HDPE (~3,000
psi). The main concern is the transfer of shear stress to the liner-soil interface. A conservative approach to
quantify this is outlined in 3.3.2 (pg. 18) of the technical catalog. We assume all the shear stress is
transferred to the liner-soil interface. The only resisting force is the frictional force of the liner on the soil. You
can calculate both the frictional force and the shear stress and compare. For a less conservative evaluation
and much more realistic evaluation you would include the force of the anchors resisting the sliding.

What is the purpose of the ribbed design?

The ribs are engineered to maximize the flexibility potential of HDPE to create curves, but they also give
extra strength / stability to the product. The corrugated design helps to control high velocity flows and
creates a self scouring action so that in a rain event debris will be washed away. Another advantage is that it
allows SmartDitch to stack well for shipping purposes.

Can SmartDitch function as a treatment system?

The SmartDitch System on its own will not act as a treatment system. However, SmartDitch is a versatile
product that can be used in conjunction with floc logs and jute mats to create an extremely capable turbidity
system. This system utilizes the 24" Semi–circular SmartDtich, which is designed for above ground use, and
can easily be set up on construction sites to treat stormwater runoff before it reaches the streets and local
streams. (Please ask for a write up on this system design)

Is SmartDitch considered a "fluid control" device or an "erosion control" device?

SmartDitch can be accurately described as both. It really depends on how it is designed into the application.
And, in many instances it will have dual functionality.