Mulserydssjön is part of Nissan's water system and Sågån's sub-catchment area. The area included in Mulserydssjön's fisheries conservation area is estimated at about 121 ha. What is included, in addition to Mulserydssjön, is Grissleån and parts of Sågån and Helgaboån. The eastern and southern part of Mulserydssjön is built up of summer cottages and permanent housing. The western and northern part of the forest grows all the way down to the lake.