Golf Course Drainage Guide - PDF
Contractor List - PDF
Installation Advice for Golf Courses
I. Multi-Flow in vertical installations
Effective drainage of fairways and along cart paths is usually
best achieved with a vertical Multi-Flow installation. Bunkers
are often drained this way as well. Vertical installations
provide a sizable intercept area but leave only a narrow scar
in the turf. A 4 inch wide trench is optimal. Depth will be
determined by factors such as:
anticipated depth of maintenance practices
• desired depth of desaturation
• width of area to be drained
• required response time
• speed at which full drainage is desired
• subsurface physical features
• the location of irrigation lines.
installed Multi-Flow provides a fast and effective solution for
Line length and spacing
On a level surface, subsurface drainage of turf is most effective
within 5 to 8 feet of the drain line. Therefore, 10 to 16
foot spacings are ideal. On sloped surfaces a wider spacing
is acceptable because gravity will aid in bringing water to
the drain line. In fairways, a central collector line running
up the center with arms reaching out into low-lying areas
on either side, is frequently the best course of action.
Product size selection
A line of 6-inch Multi-Flow could reach capacity in about
150 feet of water collection. 12-inch Multi-Flow could drain
up to 235 feet of length before it reaches capacity. While
18-inch Multi-Flow could extend up to 360 feet. These lengths
are based on the assumption that the line is collecting water
from a 12 foot wide area during a one inch in one hour rainfall
paths frequently serve as a barrier and collector of water. Multi-Flow
provides an escape route.
After water has been collected by the Multi-Flow system, it
must be transferred to a transport system for its journey
from the site. This maximizes the total output of the system
in a given amount of time. Sometimes the water is discharged
into a storm sewer, stream or pond. Increasingly, it is collected
for reuse in irrigation.
transport lines need to have a carrying capacity at least
equal to the sum of all of the collector lines they are called
on to service. For planning purposes it is useful to assume
6-inch ..................17 gpm
12-inch................. 29 gpm
18-inch................. 45 gpm
3-inch................... ..52 gpm
4-inch.................. 112 gpm
6-inch.................. 327 gpm
PVC components can be slipped over any Multi-Flow multi-purpose
connector to transition from collector lines.
there is any danger that the water level at the discharge point
will rise higher than the level of the collection system, a check
valve should be installed on the discharge pipe. This will prevent
contaminated water from backing up into the collector lines and
behind trencher like this Toro is ideal. The 4-inch trench results
in minimal disruption and minimal down time for the course.
4-inch chain trencher and trenching spade
• turf utility vehicle
• utility knife
• laser level
• centering device(s) (optional)
• water and/or vibratory packer (optional)
is easily cut to length using a common utility knife.
appropriate size of Multi-Flow pipe for collector system
appropriate Multi-Flow connectors
clean, very coarse sand
PVC or ABS pipe for transport system
PVC or ABS adaptors if needed
Plot a path through the problem area to a desired discharge
point marking the path with paint or flags. Begin trenching
at the discharge point and proceed toward the highest point
of the problem area. Measure regularly to ensure that you
are maintaining a proper grade. A laser level or transit is
a useful tool in this situation.
If the excavated material contains clay, remove it from the
site before installing the drain.
out the pipe beside the trench and lower it into place, Use Multi-Flow
connectors to ensure a secure transition between lines.
Laying out the drain
Roll out the drain beside the trench. At the ends, pull back
the geotextile filter and snap the connectors in place. Connectors
slip on more easily if they are manually pre-stretched. Push
the fittings, such as end caps, couplers, side outlets or
end outlets, firmly over the pipe to ensure a secure fit.
Then pull the fabric over the fitting and hold it in place
with PVC pipe tape. This ensures that soil will not enter
behind the fabric and block the drain core during placement.
Do not place Multi-Flow into a trench that contains standing
Connecting to transport system
Usually connection to the transport system will be made
with a multi-purpose connector. Most commonly this will
be a 0600M, 1200M, or 1800M. These connectors empty from
the bottom. Smooth, solid, rigid pipe makes for the most
reliable transport system. Use of pipe cement will ensure
a lasting connection. Multi-purpose connectors join to 3-inch
PVC elbows and tees.
a multi-purpose connector is used, the transport pipe is located
beneath the level of the collector pipes.
In some situations it is preferable to discharge the water
through an end outlet or a side outlet (e.g. 06003 or 06004).
In these cases, cut the plastic membrane covering the opening
of the outlet so that the exit pipe fits in snugly and is
located at the bottom of the fitting. Insert the exit pipe
and seal the joint using PVC pipe tape to prevent soil intrusion.
6-inch Multi-Flow connectors attach to a 3-inch PVC while
12 and 18-inch Multi-Flow match 4-inch PVC.
When an end or side outlet is used, the transport
pipe is located at the same level as the bottom of the collectors.
Use clean very coarse sand to fill the trench. Hold Multi-Flow
in the relative center of the trench while backfilling. Centering
devices are helpful in this task. Bring the sand up to the surface
or near to it. Jetting the sand-filled trench with water will
help to settle the sand in place more quickly. A small vibratory
packer also works well.
can be blended with the sand at the surface of the trench to
create a better turf growing medium. Never, however, cap the
trench with clay or other dense impermeable material. For more
information on this topic see Selecting
Centering devices are helpful for holding Multi-Flow
in the middle of the trench while backfilling.
Multi-Flow in horizontal installations
to their construction and heavy traffic, it is imperative that greens
be well drained. Newly constructed greens are best drained with
horizontally installed Multi-Flow.
Think it through before you start.
A horizontal placement of Multi-Flow is usually the most effective
way to design drainage in a new golf green. Before exploring
this method, we will first discuss green drainage in a more
you are dealing with a USGA-style layered green, a California-style
single material green, or even a pushup-style green, an effective
subsurface drainage system is a must. Assuming that the green
has been constructed using porous materials, water will soon
arrive at the relatively impermeable subbase. If it does not
have an easily accessible escape route from here, the green
will become saturated. This invariably results in unacceptable
growing and playing conditions.
primary considerations influence subsurface golf course green
drainage plans and practices:
- Does the system provide adequate drainage?
- Will the system be damaged by maintenance practices?
- Will the system avoid future failure and blockage?
addresses these concerns by providing systems that are: 1.
low profile, 2. intensively patterned, and 3. adequately filtered.
is simply rolled out over the subgrade where it lies out of reach
of cup cutter and coring equipment.
Multi-Flow’s structure and shape provide unique drainage
advantages. Its flat profile provides superior surface area
allowing more opportunity for water to enter the system.
Its superior strength significantly reduces the risk of
being crushed. And its internal flow characteristics allow
water to leave the green area quickly.
it need not be trenched in but is simply rolled out over
the subgrade where it lies out of reach of cup cutters and
Conventional wisdom has often placed drainage collector
lines only in the low points of the green subbase. The assumption
was that since water will find these low-lying areas anyway
and since greens allow water to move freely, this is all
that is necessary.
practice overlooks the effect that moving water has on the
structure of the green. Moving water carries fine particles
with it. The more water that moves and the higher velocity
at which it moves, the more soil it will carry with it.
Installing drain lines further apart requires that water
move in greater volume to fewer collection points. This
results in greater soil migration which causes a break down
of the soil structure and a potential blocking of drainage
With closely spaced Multi-Flow lines, particle movement is significantly
reduced. This increases drainage efficiency and dramatically extends
the life span of the green.
on a golf green should be gentle and thorough. Intensive
patterning decreases the velocity of the water movement
and consequently protects the fragile integrity of the green
structure. Spreading drainage lines out over the entire
subgrade of the green means that water has less distance
to travel and results in less soil migration.
locating lines closer together also ensures a prompt and
thorough drainage. Look at the veins on the back side of
a leaf for a model of effective drainage. The less distance
water needs to travel to reach an escape route, the better
the drainage is. Intensively patterned drainage allows for
the removal of significant amounts of water in a short time
without disrupting the structure of the soil.
Two separate filters assure that the drainage system will
not fail. Multi-Flow’s 4-ounce, needle-punched geotextile
wrap prevents sand from entering the flow channels. Two
inches of clean, very coarse sand effectively protects the
geotextile from blockage due to silt and other soil fines.
veins on a leaf are a model of effective fluid transfer in nature.
It is also true on a golf green: the less distance water needs to
travel to an escape route, the better the drainage is.
System design and layout
When designing drainage for a green, the main Multi-Flow collectors
should lie horizontally on the subgrade and be placed along
the line of maximum fall. A 4-inch PVC pipe should be placed
directly below the main line, exiting the green at the low
end. PVC tees must be installed in the PVC lines, pointing
upward, at each location where a Multi-Flow double wye will
connect to the laterals. The PVC pipe should be backfilled
with native soil, leaving only the opening to the PVC tee
exposed and lying flush with the soil surface.
a geotextile fabric is to be used as a barrier between unstable
subsoil and the gravel drainage blanket as in a USGA green
or between the subsoil and the green mix as in a California-style
green, it should be installed at this time, and openings should
be cut into the barrier fabric for the PVC tees to emerge
through. Typically, the barrier fabric should not cover the
Multi-Flow drainage product. Locate lateral Multi-Flow collectors
across the slope of the subgrade, allowing a natural fall
to the main line, where they will connect into the double
pattern in a herringbone configuration provides uniform drainage
to every part of the green.
the transport pipe beneath the trunk collector line is both effective
lines should be spaced not more than 12 feet apart and extended
to the perimeter of the green. Lines should be placed in water-collecting
depressions, if they exist.
the green exceeds 100 feet in width, an additional herringbone,
or half herringbone, must be installed along one side of the original
pattern in order to maintain maximum flows.
the low end of the gradient, adjacent to the main line’s
exit from the green, vertical drainage product should be placed
along the perimeter of the green, extending to the ends of the
first set of laterals. This smile drain will facilitate drainage
of the water that may accumulate at the low end of that drainage
area. The vertical drainage product can be discharged into the
4-inch PVC pipe by way of a Multi-Flow connector, such as a 06009,
and a PVC tee as it exits the green.
Wherever the grade exceeds 3%, stakes should be placed to
prevent movement of the Multi-Flow during later stages of
Avoid applying more than 6,000 psf to the Multi-Flow during
construction. Once the 2- inch band of sand is in place,
additional pressure on the Multi-Flow is permissible.
The geotextile filter fabric should be securely taped to
all fittings to prevent the infiltration of sand or soil
Maintain a grade of at least .5%; 1% is preferable.
If the PVC transport system terminates in a stream or pond
that is likely to reach the height of the exit pipe, a check
valve must be installed to prevent back flow through the
very coarse sand acts as an excellent filter, dramatically extending
the life expectancy of the system. A 2 inch band should be installed
covering the top and sides of each collector line.
Backfill material may be the single most important factor affecting
the longevity of a drainage system. Sand functions as a filtration
tool, removing silt and clay particles, while allowing water
to pass through. A 2- inch band of very coarse sand should be
installed covering the top and sides of each collector line.
This sand backfill could be eliminated if the select aggregate
is free from silt and clay but this is seldom the case. See
Selecting Backfill Material
for more information on this topic.
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