After considerable improvements of wastewater treatment, the loads of nutrients and plant protection agents, deriving from agriculture and heavy metals from urban drainages effluents as well as from erosion of agricultural soils are the main sources of nutrients and harmful substances in the loads of water bodies. On account of this, the Environmental Agency has initiated the project "Evaluation of policy measures and methods to reduce diffuse water pollution", focussing on agriculture and urban drainage. The targets of the project were on the one hand the analysis of the political and legislative framework of both policy fields and on the other hand the evaluation of several, selected water protection measures with regard to their contribution to reduce water pollution, their economical effects as well as their political enforceability.