Ditching refers to the construction of a ditch or ditches. It can also refer to the digging of ditches or furrows in for purposes of drainage or irrigation.
"ditch, v.1". OED Online. December 2016. Oxford University Press. http://www.oed.com/view/Entry/55927?rskey=bzgNTE&result=1&isAdvanced=false (accessed February 07, 2017).