To maintain an effective drainage network, the drains have to be deepened, or ditched. This is normally done after production in the autumn and again prior to production in the spring. The machine used for this operation is called a ditcher. It consists essentially of a powered wheel or disc that is lowered into the drain and removes peat from the bottom and sides of the drain. The peat (spoil) that is removed is distributed by the ditcher onto an adjoining field where it dries and hardens. Fields are also shaped with grades or screw levellers to permit run-off. This also allows efficient collection of the milled peat layer during the production process