3.0 Sedimentation of Long Point Bay

3.5 Past, present and potential management actions to address sedimentation

The Long Point Region Conservation Authority (LPRCA) and the Ministry of Natural Resources (MNR) have been precedent-setting in their implementation of erosion control programs aimed at reducing the amount of valuable topsoil entering waterways. Because the majority of the sediments entering the Big Creek Marsh and Inner Bay originate in the Big Creek catchment, these erosion control programs will probably have a substantial long-term benefit for the ecological functioning of Long Point Bay. The International Joint Commission (IJC), Ontario Ministry of Agriculture, Food and Rural Affairs (OMAFRA), and the Regional Municipality of Haldimand-Norfolk (Region) have also been involved in reducing erosion and the input of sediments to waterways throughout the region. These agencies have been actively involved in extending assistance, advice, and labour to landowners, as well as in providing education, and influencing land-use policy. The majority of the extension projects in the Long Point area are aimed at stream bank and gully erosion control, and are primarily funded through the OMNR, LPRCA, and OMAFRA.

Erosion control strategies that are particularly effective, and actively supported by local authorities, are vegetative filter strips, conservation or minimum tillage, crop rotation, grassed waterways, cedar windbreaks, spring vs. fall plowing, and the use of cover crops (see Chapter 9). These strategies contribute to the sustainability of local agriculture and are also very effective ways of minimizing the water quality problems associated with erosion and sedimentation and should therefore continue to be promoted throughout Old Norfolk County.

Vegetative filter strips (VFS) are a particularly effective means of reducing erosion and the deposition of valuable topsoil into waterways. VFS's are strips of permanent vegetation that are planted along streams and rivers to suppress diffuse-source loads of sediment and contaminants (Cooper and Lipe 1992). Studies conducted by Robinson et al. (1996) suggest that a 9.1 m wide VFS of grass can reduce the amount of sediment loading from cropland to adjacent streams. These streamside buffers result in increased water infiltration, reduced runoff volumes, and decreased runoff sediment concentration (Robinson et al. 1996). This can be attributed to the fact that root systems hold soil in place, which reduces the possibility that soil will be eroded, while the plant itself impedes water flow, thereby reducing the sediment carrying capacity of that water (Tollner et al. 1976; Robinson et al. 1996). However, the steep slopes that are characteristic of Big Creek and its tributaries dictate that VFS be as wide as possible to effectively impede water flow. Another benefit of streamside buffers is that they provide nesting habitat for waterfowl and other ground nesting birds. However, narrow strips of vegetation are easily searched by nest predators such as foxes, skunks and raccoons. Consequently, it is also imperative that filter strips are as wide as possible to provide suitable and safe nesting habitat for birds.

While erosion and sedimentation control programs in Haldimand-Norfolk have been extremely active and efficient, databases and management programs could be better coordinated throughout the region. Sediment management criteria should be formalized based upon clearly defined goals for acceptable rates of erosion and sedimentation.