Fig. 5. Output of the ExtendSim estuarine box-model for the estuarine part of the Scheldt for business-as-usual in 2006 and for measures (2) to (5) combined in 2038 (Fig. 4). EU Water Framework Directive standards of good ecological status are 2.5 mg N/L of total N for the river stretch and 0.46 mg N/L of winter dissolved inorganic N (taken from the river basin management plan, RBO Schelde 2008). The latter corresponds to 0.7 mg N/L of total N in 2006, which we used here for graphical reasons. Annual mean total nitrogen in the inflowing North Sea water from the south into the coastal zone off the Scheldt is on the order of 1.2 mg N/L.