What is two stage ditching all about? It has come to my realization that we talk about how great two-stage ditching is, but haven't taken the time to concisely describe what it is all about. So I'm going to try and provide a short version in about 300 words or less.
You know how water has a mind of its own in a ditch that is not sized properly? Weaving and winding its own path? Although weak in any one moment, the constant flow of even the smallest stream persists to generate power strong enough to erode the land, shaping a path of it's own mind. The problem with traditional ditches is they are one size, while water levels, as we know all to well, are far too variable to design the perfect ditch. Two-stage ditching address this problem.
Two-stage ditching is the design of a ditch that holds both low, and high water flows by creating a smaller channel, almost a 'mini ditch,' inside a larger ditch. The smaller ditch is shaped and designed so the water doesn't have the space to meander during low water flow periods. In the event of a downpour, the larger ditch has the capacity to hold the larger flow, protecting the surrounding land of overflowing.
When properly built, the larger ditch withholds vegetation of the land, protecting the surrounding land from erosion.
The below picture is taken from The Nature Conservancy. If you missed our previous Facebook and Twitter post about them, you can check out their information regarding two-stage ditching here.