Constructed wetlands have been proposed as cost effective and more targeted technologies in the reduction of nitrogen and phosphorous water pollution in drainage losses from agricultural fields in Denmark. Using two pig farms and one dairy farm situated in a pumped lowland catchment as study cases, this paper explored the economic feasibility of implementing a constructed wetland. Sensitivity analysis was conducted by varying the cost elements of the wetlands so as to establish the most cost effective scenario and a comparison with the existing nutrients reduction measures carried out. The analysis show that cost effectiveness of the SFCW is higher in the drainage catchments with higher nutrient loads. The range of the cost effectiveness ratio (CER) on nitrogen reduction differs distinctively with that of catch crop measure. The study concludes that, SFCW would be a better optimal nutrients reduction measure in drainage catchments characterized with higher nutrient loads.