Nearly 70 smaller watersheds outlet directly into Lake Huron in the Ausable Bayfield Conservation Authority (ABCA) area.
These smaller watersheds are found from Grand Bend north to the boundary between the ABCA and the Maitland Valley Conservation Authority.
The average catchment area for these small watersheds is three square kilometres.
The watersheds north of Bayfield (Bayfield North) cover a 40 km² area that has a higher percentage of forest cover (30 per cent), compared to the watersheds south of Bayfield (South Gullies) (199 km² area with forest covering 11 per cent).
Bayfield North Watersheds Management Plan
The community north of Bayfield has been working with the ABCA and provincial and federal agencies to implement and monitor agricultural best management practices since 2008.
The Bayfield North Watersheds Plan documents the natural, social and economic features of the watersheds north of Bayfield; identifies management strategies to address current community interests and issues; and makes recommendations to the community to continue to enhance and protect the natural environment in the area north of Bayfield.
This project is part of a larger initiative termed the Lake Huron-Georgian Bay Watershed Canadian Framework for Community Action, which encourages the active participation of individuals, groups and communities, in identifying common issues, and the conservation and stewardship of natural resources.
Watershed Based Best Management Practices Evaluation Program (Crops and Creeks Huron)
Gully Creek has been of particular interest and is an area of intense Best Management Practice (BMP) implementation and monitoring efforts.
In addition, research partners from the University of Guelph, led by Dr. Wanhong Yang, developed a Soil and Water Assessment Tool (SWAT) model, which is a hydrologic model that can be used to help determine the collective effect of the BMPs at a watershed scale.
The BMPs evaluated over the past ten years include conservation tillage, cover crops, nutrient management, water and sediment control basins (WASCoBs or berms), and a grass filter strip.
Some of our main findings can be summarized in the following points:
- At the field scale, structural projects (such as WASCoBs and grass filter strips) seem to reduce pollutant transport, mainly for sediment and phosphorus (P);
- At the field scale, the effect of land management practices was harder to determine due to difficulties in collecting water. Due to these difficulties we had to rely on modelled results. The modelled results showed pollutant reductions related to cover crop adoption and conservation tillage practices;
- At the watershed scale, modelled results found that phosphorus reductions were relatively small due to the small scale of the BMP implementation;
- Watershed monitoring results show negligible reductions possibly due to the small scale of BMP implementation, the effects of conventional management practices, or potentially weather related variability; and
- Broad application of a systematic – 'avoid, control, trap and treat' – approach to BMP implementation have yielded more significant modelled reductions in P at the watershed scale.
Evaluation has helped to develop a broader awareness around the importance of cover crops, improved soil health, and a systematic approach to BMP implementation. Changes implemented across the watershed and across the landscape help improve and protect Lake Huron.
Please read the complete report for more information on this important research:
- Bayfield North Watersheds Management Plan (PDF file)