As water continues to flow down the Assiniboine, flooding farms and residential property, we need to collectively look at measures to deal with watershed management not only in our local area but throughout Manitoba, as well as involving Saskatchewan and the neighbouring states.
Drainage has long been an important component in agriculture and property management. Land with flat, poorly-drained soil requires draining for preparation and planting.
Yet what we have done to gain proper drainage has influenced the landscape in Manitoba over hundreds of years. Draining of wetlands, tillage practices and deepening of ditches are just some of the ways that we have changed the flow of waters, creating an unintended threat.
Water, when confined to a channel such as a stream or ditch, has the potential to cause great destruction. If there is too much water moving through an undersized area of land, then there is nowhere for it to go but to rush out of its barriers. This is something local residents along the Assiniboine are dealing with right now.
Bank erosion, scouring, and flooding are signs that there is problem with how the water is drained from our soil. At a recent conference that featured representatives from Manitoba, North Dakota, South Dakota and Minnesota, we learned about a new type of in-stream restoration being tested called the two-stage ditch that may help.
The idea of the two-stage ditch is quite simple. It was developed by observing natural processes that form stable streams and rivers. The design incorporates a floodplain zone, called benches, into the ditch by removing the ditch banks roughly three feet above the bottom for a width of about 10 feet on each side. This allows the water to have more area to spread out on, decreasing its speed but, as important, actually increasing the amount of water moving through.
The two-stage ditch, when compared to a traditional agricultural ditch, can improve both drainage and ecological function. It improves ditch stability by reducing water flow and the need for maintenance, saving labour and money.
There are many more innovative methods neighbouring jurisdictions are testing to properly manage the flow of water and reduce its destructive impact. Regardless of whether it is the more traditional dredging of the river or improvements to the diking system, it is going to take co-operation, co-ordination and it can’t wait any longer.
If you don’t believe me, just take a drive down to the St. François Xavier area.