This integrated modeling system calculates nutrient emissions to water from agriculture and nature land areas in the Netherlands. It is designed and used for evluation at national and regional level of the effects of fertilizer policy measures for runoff and leaching of N and P to ground water and surface waters. The coupled model SWAP-Animo in STONE can distinguish the processes and sources that determine runoff and leaching to water (fertiizer use, atmospheric deposition, seepage, mineralization). This output is used by regional and national policy makers to initiate effective measures, allocate source reduction targets and underpin (semi) natural background levels in catchments of surface water bodies. Country of use: NL.