The IPGC Trench Drain
The IPGC drainage pipe is an effective, cost-efficient, and easy-to-install trench drain that will readily
capture a substantial volume of drainage runoff right at the ground surface. The
concentrated and abundant open slit area on the IPGC surface?allows for this
optimization. The IPGC Trench Drain?is able to?convey the captured runoff just
beneath the surface until it becomes necessary to install deeper lines. At that
point, the IPGC can easily be connected to standard PVC pipe with the
appropriate standard PVC fittings.
Trench Drain is not and should not be confused with a typical French Drain that
houses a standard perforated PVC pipe.
The following list
describes several benefits of the IPGC Trench Drain not provided by the French
- The IPGC trench drain will capture drainage runoff right at or just below the
ground surface, whereas standard perforated pipes in French Drains typically
begin to capture and convey runoff at least 6-12 inches below the ground.
The concentrated and abundant open slits on the surface of the IPGC drainage
pipe practically eliminate ponding at the surface. With French Drains,
a significant portion of the trapped runoff is never conveyed by the perforated
pipe, and must filter through the gravel to the discharge location.
- The IPGC Trench Drain is much simpler to install than a French Drain. This
is due to the fact, as mentioned above, that the IPGC open slits are ideally
located right at or just below the ground surface. French Drains typically
require at least 6-12 inches of gravel covering the entire perforated
- Essentially, the required trenching to install The IPGC drainage pipe only
needs to be deep enough to enclose the pipe up to the open slit bottoms. It
may be preferred in some cases to install a thin 2" layer of at least 5/8"
diameter gravel to cover the exposed IPGC open slits. The gravel installed
with a French Drain must also be sized appropriately to not fill up the
- Essentially, the flow capacity of the conveying pipe is the
limiting factor for conveyance. For all standard IPGC pipe lengths, The IPGC has
been designed to allow the open slit area to be far greater than the
cross sectional area of the pipe itself. Therefore, the IPGC open slits will never
inhibit pipe conveyance. With a standard perforated pipe, it takes an
unspecified length (depending on the pipe diameter), to provide this
- Overall IPGC Trench Drain installation costs will be less than for French
Drains due to the fact that no gravel is needed for trench backfill or for
trapping runoff beneath the ground.
- French Drains require cleanout installations if any maintenance is to be
simplified, and the cleanouts must be in sight. The IPGC drainage pipe is
easily maintained since it is easily accessed and replaced just at or below
- Another benefit of the IPGC trench drain is that it can be installed to
strategically position the open slits (via rotation), if it is warranted by
the situation. A French Drain does not provide an option such as
Other Benefits of the IPGC
Trench Drain include:
- The costs and efforts required to install the IPGC are much less than for
typical grate inlets, landscape drains, catch basins, & storm
- Filter fabric wrapping is not required for the IPGC if a 2" gravel layer
is applied or if the surrounding area is established with suitable
- Installing The IPGC drainage pipe is an additional way (in addition to
capturing rooftop runoff) to supplement the water supply for a rainwater
The IPGC French Drain
The IPGC French drain is simply the inverted IPGC
Trench Drain with the addition of a bottom gravel
layer. With the open slits facing downward, resting
on top of the bottom gravel layer, the IPGC drainage pipe is able
to allow substantially more stormwater into the pipe than
will a standard perforated pipe. This is because of the
abundant open area provided by the surface slits. With an identical amount of
contributing flow, the ponded depth above The IPGC drainage pipe will be
less than that which occurs for the standard perforated pipe. This fact can be verified with the
The IPGC Storm Drain
The IPGC storm drain is simply the drainage pipe itself,
however, the IPGC is able to convey stormwater more effectively than a standard
perforated pipe with the slits facing upward. This is because the bottom portion
of the pipe remains in tact from the flowline up to the bottom of the
slits. If the IPGC is installed with the slits facing downward, as a French Drain, flow
is minimally affected by small pockets between the top of the gravel layer
and the inside wall of the pipe. These small pockets will hold water until final infiltration into
the gravel occurs.
The IPGC Grate Inlet & Catch
The surface of the IPGC
performs as a grate inlet in a sump or on-grade. The actual pipe itself will
serve as a catch basin and conveyance device. When the open slits can be exposed
at the surface, the open flow area is maximized.
The IPGC Interceptor & Diversion
The IPGC can function as
both a drainage interceptor and diversion device since it will simultaneously
function as a grate inlet, catch basin, and storm drain. Along the
perimeter of a residential lot or commercial site, the IPGC can be installed to
capture flows leaving or entering the property. Once the contributing flow
is captured, the IPGC can be connected to additional PVC pipe as needed in order
to discharge at the desired location.
The IPGC Filtration Drain
When wrapped with filter
fabric and covered with porous gravel, the IPGC is an excellent filtration drain
with the following additional benefit: The additional open flow area provided by
the IPGC requires a lower head (or water depth) than a standard PVC perforated
pipe to convey the same flow rate. This means that the ponded depth will be
lower for any given flow rate at the point of capture.
Detention Pond Outlet
The IPGC is a less costly
and equally effective alternative to installing typical pond outlet structures.
Additionally, the required open area (for an orifice) can be provided within a
tolerance area of one slit. The open width for an individual slit on all
available pipe sizes is 0.25-inches. The individual open slit lengths remain
constant for a given pipe size, but as the pipe size increases so will the
individual open slit length.
Water Quality Pond Riser
For this application, the
IPGC is merely an alternative to perforated pipe, as neither seems to have a
distinct advantage or disadvantage. This is because the typical release rate
from a filtration pond is small in comparison to incoming
The IPGC makes it
relatively simple to capture surface water runoff for use in a rainwater
harvesting system. The following paragraphs describe rainwater harvesting in a
non-technical fashion for those interested in learning about the excellent
benefits of rainwater harvesting.
harvesting is an effective means for filtering out pollutants such as suspended
particulate matter and associated constituents such as bacteria, nutrients, and
metals that originate on impervious surfaces such as rooftops, asphaltic
concrete, and even man-made landscaped areas.
Although most rainwater
harvesting systems treat runoff that is captured from rooftops with gutters and
collection pipe, it is becoming more common to capture, treat, and use runoff
from impervious surface areas on a developed property. Once the runoff is
captured, it is routed to a storage tank where sedimentation occurs. Storage
tanks can be located above or below the ground, but this usually depends on the
physical constraints and how the rainwater is to be captured and used. A pump is
required for below ground storage tanks when the treated water must be lifted to
an elevation where it can resume gravity flow or is dispersed. The storage tank will remain idle
for a certain period of time, depending on the pump settings. Once released from
the tank, the treated runoff can be used for natural infiltration, landscape
irrigation, plant and lawn watering, secondary water supplies for green
buildings, and reclaimed for cooling water.
The IPGC can be used for more than just capturing
runoff for a rainwater harvesting sytem. It can also be used for disbursing the
treated runoff in order to provide natural infiltration of an area, gravity fed
irrigation, and pump-fed irrigation. The image below shows two possible
rainwater harvesting systems: each has a discharge system comprised of standard
and IPGC Schedule 40 PVC piping. To look at a larger image, just use your mouse
wheel to zoom in on it.
Please note that these
images are schematic representations and should not be used as construction
details. We highly recommend that all interested parties consult with a licensed
rainwater harvesting professional before installing a rainwater harvesting
system at your home or business. A list of nearly 40 rainwater harvesting
professionals is available from the Texas Rainwater Catchment Association Website.
The IPGC as an Erosion Control
When a section of IPGC is
used in a sump location and is either covered with gravel or wrapped with filter
fabric, very little sediment can enter the pipe. When used in this fashion, the
IPGC can significantly help to minimize sediment transport in addition to
removing potential pollutants from the runoff entering downstream waterways.
After an unspecified period of time, especially in areas with little or no
vegetation in the area contributing runoff to the sump, sediment will inevitably
accumulate in the vicinity of an IPGC section. When this occurs, the displaced
sediment should be removed in order to restore full functionality of the IPGC as
a filtration and drainage device.
If sections of the IPGC are
installed parallel to grade (or perpendicular to the direction of flow) and are
placed intermittently to intercept surface water runoff, the diplacement of
sediment caused by wash out can be minimized because of the flow reduction on
the ground surface. If used in combination with silt fencing, the IPGC can help
reduce the flow rate through the silt fence. This is desirable in situations
where construction has produced an increase in runoff and therefore an increase
in sediment displacement.