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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.