There are different ways that you can limit the number of livestock that enter your watercourses. Depending on your management goals, and the physical characteristics of your pasture, different practices will be appropriate. Excluding livestock from watercourses altogether will improve water quality, but alternative water sources are not always possible. More information about best management practices can be found below.
It should be noted, however, that ANY alteration to a stream or watercourse, including bridges, and limited access ramps, does require permission through the navigable waters act (1985). A permit is not required for fencing. More information, as well as the appropriate paperwork, can be found here.
Riparian Fences
Instead of having the fence right on the bank (where it is susceptible to ice or flooding damage), fencing should ideally be built along the outer edge of the grassy strip or at the very least, along the vegetated buffer. This allows the filtration services provided by the buffer to continue. In some cases temporary fencing may be required especially in areas where spring flooding or ice may damage the fences.
The setback width is dependent on your land management goals, the wider the setback the more filtration occurs, and the the more healthy the watercourse
Limiting Entrance to Water and Alternative Watering Sources
Of course livestock will need access to water. Ideally an alternative water source or watering system can be used such as nose pumps or solar/wind pumping systems. Sometimes, however, watercourses provide the only feasible possibility for drinking water. By limiting the location of where livestock have access to the stream, the negative impact on the watercourse can be lessened. These locations should have firm footing to prevent bank erosion and should be fenced to limit the livestock access to the edge of the waterway.
Helpful Fact Sheets
The Nova Scotia Federation of Agriculture has prepared a series of helpful fact sheets regarding limiting livestock access to riparian areas:
Limited Access Ramps
This allows cattle only part way into a watercourse, reducing harm to the habitat, while preserving the drinking source for the livestock.
Alternative Watering Systems(PDF)
Examples of alternatives to using ponds or watercourses as a water source.
Solar Pumping Systems for Livestock Watering (PDF)
Information regarding the use of solar pumps to bring water into pastures.