The Rural Voice, 1981-10, Page 12The pros and cons of
FARM DRAINAGE
by Adrian Vos
Draining means the removal of surplus
water from the land.
In Onta io this is done mainly by tiling
the fields and guiding the water from
these tiled fields through the use of
municipal drains.
Many a field would be useless without
drainage, and farmers found out long ago
that tiling was much more economical
than open ditches.
The advantage of tiling over ditches is
that tractors can be driven over the field
without the need for bridges and all the
land can be cultivated. With ditches, the
banks often cave in, filling the channel
with mud.
One of the first draining methods was to
dig a channel and put brush in the hole
before covering it with soil.
A better material was flat stones
tenting over a bed of coarse stone, or even
laid in a triangle underground. The
problem was that such drains had too
many openings to let in dirt and debris,
plugging the channel.
For these reasons tile has been used on
Canadian farms for over a hundred years.
They have been made of various mater-
ials: baked clay, cement, and now plastic.
The big advantage of tiling is that the
land warms up much earlier in the spring.
Particularly in our area, where the
growing season is short, this means
money in the bank.
Another money saver is the fact that dry
soil is much easier to work. With the price
of fuels today and in future, this is a big
advantage.
The moisture retention capacity of tiled
soil is considerable higher in a dry year.
The much less. compaction of drier soil
gives plants a better opportunity to
penetrate deep towards the constantly
needed moisture, at the same time letting
in more oxygen to the roots.
Stan Paquette, Assistant Ag. rep. in
Huron is fully in favour of drainage tiling.
He asserts that productivity can increase
almost overnight by 50 per cent or more.
His colleague at the Clinton office, Sam
Bradshaw thinks that the usefulness of
tiled land is greatly increased. However,
he is somewhat concerned about the
number of swamps that are being drained.
He worries a bit about the loss of water
storage capacity, but points out that there
is no law against it.
Warren Knight, an officer with the
Ministry of Natural Resources in the
Wingham office, says that tile drainage
increases moisture conservation. When a
field is tiled the surplus water is gradually
removed, making room for seepage from
the surface when the next rainstorm
strikes. He says that most tile systems
are designed to take half an inch (1/4 cm) of
rainfall every 24 hours. That means there
is less run-off and erosion from tiled fields
than from untiled ones. It also lessens the
severity of flooding to some extent
because of the increased storage capacity
of the soil.
In'one sense, Knight finds that tiled
fields take over the job of the swamps as a
reservoir, but only to a limited extent.
But, Knight warns, we no longer have
the water storage capacity over the long
term. He points to the Bayfield and
Ausable rivers in the south of Huron
county, which run almost dry in summer.
Charles Schenk, of the Ministry of the
Environment in London, is of course more
concerned about the environmental ef-
fects of drainage. He is not worried about
tiled fields. These don't cause environ-
mental problems he says. It's the
municipal drains he is worried about.
There are no proper environmental
guidelines, Schenk says and he would like
to see some developed. He would also
like to be informed every time a new
drain is installed so he can give advice.
The problem he sees is not so much with
agricultural chemicals seeping through
the soil into the watercourses. With the
exception of atrazine, today's chemicals
degrade rapidly. Surface run-off can be a
different matter and when drains are
improperly designed, erosion is bad, a
point made by the PLUARG report in
recent years.
Schenk would like to see "drainage
commissioners" who could make deci-
sions on the value of drains. They could do
a cost -benefit study and an environ-
mental appraisal.
Knight is a step ahead. His ministry is
already actively involved in advising
drainage engineers and drainage contrac-
tors on the design of drains. He says some
drainage engineers consider the lake the
most satisfactory outlet. He disagrees. To
help engineers and ultimately farmers, his
ministry is working with several engineers
to improve drain design.
At present they are advising on a project
which makes a swamp on a neighbouring
farm the outlet for a drain from four farms.
The neighbour has no objections as the
swamp can't be used for crop production.
And, Knight says, there is provision in the
drainage act for damage compensation.
The swamp empties into another drain
leading to the river. The swamp, in this
instance, is acting as a stage. It slows the
water run-off so it runs all summer. This
gives it also a chance to run bad_ .oto, and
supply, the water table. This drain will
reduce costs to all farmers affected
because it is relatively short and down-
stream farmers will have less trouble
with a flood of water from the higher land
being tiled. This also reduces erosion in
spring.
Schenk says farmers generally are
becoming more aware of potential pro-
blems with drainage and are doing
something about it. Crop rotations to
reduce erosion are becoming more com-
mon.
Knight and Schenk are both concerned
about poorly designed drains. The design
work is in many cases done in the same
(Cont. on PAGE 18)
PG. 10 THE RURAL VOICE/OCTOBER 1981