?Development of methods for the planning and implementation of ditch clearing with modern methods?, is a long title for an exam work but that is what this report describes. In Sweden, we have a limited area available, and with the present development with increasing market oil prices, and enormous forces on the renewable energy sources, we need every hectare possible to protect the output of the forests. So with this in mind, many people are now considering how to increase the production of the forests that are already available. A part of production increases is to manage the existing forests, and not to allow this area to go to cultivation or become marshland. We manage our forests in a way that benefits the environment, and we consider that our working practice over the years has shown us to be correct and well functioning. A part of our way of producing forests is to ensure that we have functioning drainage systems in the forest holdings which we administer. The responsible at Holmen Skog requested a good method to make inventories of the drainage systems of Holmen forests. This Degree Project is about ways to identify and implement drainage systems with modern methods. It deals with authorities regulations, and how they operate in different counties.

Ökad efterfrågan på virke har lett till ett ökat intresse för och användande av olika produktionshöjande åtgärder. En sådan åtgärd är Dikesrensning som innebär att befintliga diken eller dikessystem rensas för att de skall bibehålla eller återfå sin ursprungligt avvattnande och produktionshöjande funktion. Sveaskog avser att öka omfattningen av Dikesrensning. Därför behövs en kartläggning av behovet på deras marker. På samma gång behöver produktionseffekterna och livslängden på dikena utrönas. Studien genomfördes via en studie av befintlig litteratur om skogsproduktionseffekter efter Dikesrensning och dikning samt förfall och livslängd hos diken.

During the 20th century a significant proportion (about 15 %) of the peat-covered wetlands in Sweden were drained to improve forest productivity. Area wise, most of the forest drainage was done in northern Sweden, but relatively speaking a larger part of the wetlands have been drained in the southern parts of the country. Most often, the forest drainage resulted in increased forest growth, but failures were not unusual, and harmful effects, e.g. on species richness, have been a common cause for draining. Ditch cleaning is necessary for maintaining the ditches in good condition.