HomeMy WebLinkAboutThe Goderich Signal-Star, 1983-04-20, Page 18Page 2—Valleys and People
St dies of the Maitland watershed
DATA COLLECTION
In an attempt to collect in-
formation on where and what the
major resource management
problems are in the Maitland
watershed, detailed studies of
specific areas have been com-
pleted.
It has been stated that in south-
western Ontario, agricultural
activities create the greatest
overall impact on water quality.
However, exact documentation
on the severity and impact of soil
loss due to sheet erosion, ditch -
bank erosion, and cattle access is
limited. A study was undertaken
in the Maitland watershed in 1982
to obtain this needed documenta-
tion.
The study was a cooperative
effort between the Maitland
Valley Conservation Authority,
the Ministry of Environment and
the local farm community.
FARMING COMMUNITY
STUDIED
Land use patterns and prac-
tices in two small watersheds
were surveyed, using a variety of
techniques including aerial
photograp'iy. Water samples
were collected at 40 different
locations along the Upper Blyth
Brook and Murray Lamb drain-
age systems. These two rural
areas were chosen because both
areas display a variety of agri-
cultural uses; are virtually un-
affected by urban influences; and
have permanent stream flows. At
the same time, the two areas
display significant differences.
The Murray Lamb drainage
system is more intensively
farmed for cash crops, than the
Blyth Brook drainage area,
where mixed farming dominates.
COMPONENTS
OF THE STUDY
Water samples were taken up-
stream and downstream of cattle
access points throughout the two
small watersheds. The source
areas of these two streams were
also surveyed. All land owners in
the two basins were interviewed
to obtain information on current
management practices being
incorporated into their farming
operation. Soil loss estimates
were calculated for a variety of
field crops. Some land owners
assisted Authority staff by
measuring and recording the
time and amount of rainfall
during the study period of June to
October.
PRELIMINARY
FINDINGS
There are several.findings with
regard to the impact' of farm
practices on water quality.
Firstly, there appears to be
definite negative impact on water
quality from cattle accessing the
creek. The analysis of the water
samples was taken upstream and
downstream of these access
points. The analysis also indi-
cated that where cattle had direct
access to the stream, the impact
on water quality was greater
than where cattle were fenced
SUMMER 1982—Land use activities in the Blyth Brook and Murray Lamb drainage areas were identified with the aid of aerial
photography.
off . At isolated locations, salmon-
ella bacteria was present.
During the study period, addi-
tional water samples were col-
lected for analysis before, during
and following rain storm events.
The findings of these analysis
show a 3 to 4 fold increase in con-
centrations of phosporus, organic
nitrogen and suspended solids
during these summer storms.
Drain clean-out practices were
also identified as having a nega-
tive impact on water quality. A
portion of the study area, along.
the Murray Lamb Drain ,was
undergoing a clean-out during the
study period. Analysis conducted
on water samples taken before,
during and after construction,
showed a significant increase in
suspended solids (sediments),
reaching excessive levels during
the drain construction.
The impact of tile outlets on
water quality was also studied.
The findings in this case were not
as expected. Variations in the
quality of the water was found to
be related to the soil texture not
crop type as previously thought.
Generally, however, all water
discharged was high in nitrate
concentrations.
The potential amount of soil
movement or loss from a field
was found to be affected by crop
type' and farm management
Valleys and
People.
"VALLEYS AND PEOPLE" is a publication of the Maitland
Valley Conservation Authority, a non-profit, corporate body;
established under the Conservation Authorities Act of Ontario
to manage the natural resources of the watershed and related
conservation projects in partnership with its member munici-
palities and the Province.
Edjttor: A. Beecroft
practices. Other factorscon-
sidered in estimating the
potential for soil movement or
loss included soil type, the slope
of the land, and a rainfall and
snow -melt factor. The average
estimated soil loss in the two sub -
basins was found to be 3 to 6 tons
per acre per year. This rate is
considered a `tolerable' loss,
based on the Ministry of Agri-
culture and Food's research. In
the study area, however, some
fields had potential erosion rates
in excess of 10 tons per acre per
year. Further investigations re-
vealed that between 1 and 2 per-
cent of this total soil loss entered
the streams. While this seems to
be a small percentage, the
volume of soil delivered to the
streams annually, is in the range
of 600 tons on the Blyth Brook and
1000 tons on the Murray Lamb
Drain.
The overall condition of the two
sub -basins appears to be good.
However, portions of each basin
are showing signs of poorer
health and remedial measures
should be considered in such
areas.
NEXT STEP
The results of this study will be
summarized and presented to the
Ministry of Agriculture and Food
and the residents of the two sub -
basins. The Authority, hopefully
in conjunction with the Ministry
of Agriculture and Food and the
Ministry of the Environment and
local farm organizations, will
work with the land owners on
individual conservation pro-
grams in the identified problem
areas of the watersheds. Our
intent is to make the landowner
aware of his problem, what it
means to him financially, and
provide him with cost effective
remedial alternatives.
WATER QUALITY CHECKED—Water samples
were dollected at 40 different locations
throughout the two sub -basins for analysis.