The aim of this thesis is study the condition of water pollution control systems and compare them to the directives. Another aim is to study the reliability of RLGis-software in erosion assessment. The field work was conducted with ArboWebForest service which is also in test use.

The methods used in the study were literature study and field investigation. The tools in the field investigation were normal measurement tools and visual observation. Observation data was saved in a mobile phone and after that sent to a server via mobile network. The resulting database was retrieved from the server for processing and analysis.

The analysis shows that there are problems with water pollution control. In many cases the pollution control basins were too small or they were almost full of silt. The small size is caused by engineering errors where river basins are measured too small. Also, there were too few silt holes, which seems to be caused by weak engineering where holes are not drawn in maps.

RLGis–software seems to be a good assessment tool at least for contour ditches. In peripheral and duct ditches the assessment is not so reliable and other methods have to be used to assess the erosion risk. ArboWebForest was found to be a usable tool to collect natural resource data.