The Rural Voice, 2001-03, Page 18Helping meet the growing water
conservation need in Ontario
Photos and story by J. D. Hisey
Jn
the April 2000 issue of The
Rural Voice, an article by Robert
Mercer described the global
problem of available water for
agricultural production. Ontario is
blessed with an annual precipitation
of 78 to 90 cm., most of which falls
in the Great Lakes area basin. The
same area has also the best
agricultural land in the province. If
this total amount of rainfall were
distributed at regular, more -or -less
equal intervals throughout the
growing season, the provincial farm
output could be increased
considerably. We have too much
rainfall when it is not needed and too
little when it is needed for the
growing season.
Since earth -moving equipment is
now readily available in most farm
areas, much of the need for water at
critical stages of plant growth could
be satisfied without drawing on
ground water supplies from depleting
aquifers if excess spring run-off were
to be captured and stored in surface
ponds. Few farms are devoid of areas
which could be converted to water
14 THE RURAL VOICE
Fara ponds oan add beaujy as welt .as
sonaervin r:watetir . � .
storage use by an affordable amount
of earth moving. Of ponds there are
essentially three types:
• 1. Dams on continuously -flowing
streams.
• 2. By-pass Ponds
• 3. Dug -out Ponds
• 4. Spring -fed Ponds
Type 1 storage ponds are now
almost off limits for the individual
farmer since conservation authorities
were made responsible for flood
control following Hurricane Hazel in
1954. The cost of meeting all
engineering requirements and the
documentation and approvals
required discourage the most
ambitious farmer from choosing this
route to water storage.
Type 2, the By-pass Pond is -
presently the preferred choice. It can
be designed to fill during high flow
levels and to retain its water after the
flood has passed. It should be of such
a size that it retains more water than
that required for irrigation during
droughts such as in 1998 and 1999.
Ground leakage and evaporation must
be provided for. Such ponds should
be located as nearly as possible to the
fields which will require the
irrigation.
Type 3, the Dug -Out Pond can be
located at any suitable site having
regard to the crops to be irrigated.
This type of pond is most sensitive to
the soil permeability. It may also tap
a high-level aquifer and be fed as a
spring -fed pond. Since it will usually
have to be fed by pump or siphon
from the nearest stream when it is at
peak flow and no more is available in
dry weather, it must be Targe enough
to meet all expected needs. Unless
there is a high ground -water level, the
pond should be lined with an
impervious layer or there may be no
water when it is most needed.
Evaporation will remove an amount
almost equal to rainfall so that
precipitation alone will not be
sufficient. Artificial liners are
available but they are expensive and
must be installed by experienced
personnel with proper equipment not
usually available to the farmer.
Type 4, the Spring -fed Pond, as its
name implies, receives its supply