We investigated the effects of changes in land use and an increase in groundwater table level on nitrogen, phosphorus, and carbon leaching to the groundwater at six sites in the Drömling fen area (Germany). Changes in land use from intensive crop production to unimproved pasture decrease the amount of seepage water. The leaching of nitrogen from soil to groundwater was reduced. The higher water tables during winter increased phosphate and DOC fluxes to the groundwater due to a decreased redox potential, which increased phosphorus solubility, and intensified leaching of dissolved organic matter from the peat.