Index: doc/wflow_sbm.rst
===================================================================
diff -u -r1d361b87fcfff19ff195f221c386fa0118481780 -r80ea4904654f975514dac4fb2258e48bfd880490
--- doc/wflow_sbm.rst	(.../wflow_sbm.rst)	(revision 1d361b87fcfff19ff195f221c386fa0118481780)
+++ doc/wflow_sbm.rst	(.../wflow_sbm.rst)	(revision 80ea4904654f975514dac4fb2258e48bfd880490)
@@ -552,7 +552,7 @@
 
 Soi evaporation is scaled according to:
 
-:math:`soilevap = potensoilevap * SaturationDeficit/FirstZoneCapacity`
+:math:`soilevap = potensoilevap * SaturationDeficit/SoilWaterCapacity`
 
 As such, evaporation will be potential if the soil is fully wetted and it decreases linear
 with increasing soil moisture deficit.
@@ -591,21 +591,21 @@
 
 ::
 
-    FirstZoneDepth = FirstZoneDepth - ActEvapSat
+    wetroots = sCurve(WTable, a=RootingDepth, c=smoothpar)
+    ActEvapSat = min(PotTrans * wetroots, SatWaterDepth)
+    SatWaterDepth = SatWaterDepth - ActEvapSat
     RestPotEvap = PotTrans - ActEvapSat
-  
-    # now try unsat store  
-    AvailCap = min(1.0,max (0.0,(WTable - RootingDepth)/(RootingDepth + 1.0)))       
-	
-    MaxExtr = AvailCap  * UStoreDepth
-    ActEvapUStore = min(MaxExtr,RestPotEvap,UStoreDepth)
+
+    # now try unsat store
+    AvailCap = max(0.0,ifthenelse(WTable < RootingDepth,  cover(1.0),  RootingDepth/(WTable + 1.0)))
+    MaxExtr = AvailCap * UStoreDepth
+    ActEvapUStore = min(MaxExtr, RestPotEvap, UStoreDepth)
     UStoreDepth = UStoreDepth - ActEvapUStore
-    
+
     ActEvap = ActEvapSat + ActEvapUStore
 
 
-
-Remaining evaporative demand is used to for evaporation of open water. This amount
+Remaining evaporative demand is split between  evaporation of open water and soil evaporation. This first amount
 is subtracted from the water that would otherwise enter the kinematic wave.
 
 Capilary rise is determined using the following approach:
@@ -647,7 +647,7 @@
 Leakage
 ~~~~~~~
 
-If the MaxLeakage parameter may is set > 0  water is lost from the FirstZone and runs out of the model.
+If the MaxLeakage parameter may is set > 0  water is lost from the Saturated zone and runs out of the model.
 
 Soil temperature
 ~~~~~~~~~~~~~~~~
@@ -730,7 +730,7 @@
     self.DemMax=readmap(self.Dir + "/staticmaps/wflow_demmax")  
     self.DrainageBase=readmap(self.Dir + "/staticmaps/wflow_demmin")        
     self.CC = min(100.0,-log(1.0/0.1 - 1)/min(-0.1,self.DrainageBase - self.Altitude))
-    self.GWScale = (self.DemMax-self.DrainageBase)/self.FirstZoneThickness / self.RunoffGeneratingGWPerc
+    self.GWScale = (self.DemMax-self.DrainageBase)/self.SoilThickness / self.RunoffGeneratingGWPerc
 
 
 
@@ -761,14 +761,16 @@
 
 in dynamic::
 
-        self.AbsoluteGW=self.DemMax-(self.zi*self.GWScale)
-        self.SubCellFrac = sCurve(self.AbsoluteGW,c=self.CC,a=self.Altitude+1.0)
-        self.SubCellRunoff = self.SubCellFrac * FreeWaterDepth
-        self.SubCellGWRunoff = min(self.SubCellFrac * self.FirstZoneDepth,\ 
-            self.SubCellFrac * self.Slope * self.FirstZoneKsatVer * \ 
-            exp(-self.f * self.zi) * self.timestepsecs/self.basetimestep)
-        self.FirstZoneDepth=self.FirstZoneDepth-self.SubCellGWRunoff
-        FreeWaterDepth = FreeWaterDepth - self.SubCellRunoff
+            self.AbsoluteGW = self.DemMax - (self.zi * self.GWScale)
+            # Determine saturated fraction of cell
+            self.SubCellFrac = sCurve(self.AbsoluteGW, c=self.CC, a=self.Altitude + 1.0)
+            # Make sure total of SubCellFRac + WaterFRac + RiverFrac <=1 to avoid double counting
+            Frac_correction = ifthenelse((self.SubCellFrac + self.RiverFrac + self.WaterFrac) > 1.0,
+                                                     self.SubCellFrac + self.RiverFrac + self.WaterFrac - 1.0, 0.0)
+            self.SubCellRunoff = (self.SubCellFrac - Frac_correction) * self.AvailableForInfiltration
+            self.SubCellGWRunoff = min(self.SubCellFrac * self.SatWaterDepth,
+                                       max(0.0,self.SubCellFrac * self.Slope * self.KsatVer * \
+                                           self.KsatHorFrac * exp(-self.f * self.zi)))
 
 
 
@@ -955,14 +957,14 @@
     node[shape=record];
     UStoreDepth [shape=box];
     OutSide [style=dotted];
-    FirstZoneDepth [shape=box];
-    UStoreDepth -> FirstZoneDepth [label="Transfer [mm]"];
-    FirstZoneDepth -> UStoreDepth [label="CapFlux [mm]"];        
-    FirstZoneDepth ->KinematicWaveStore [label="ExfiltWaterCubic [m^3/s]"];
+    SoilWaterDepth [shape=box];
+    UStoreDepth -> SoilWaterDepth [label="Transfer [mm]"];
+    SoilWaterDepth -> UStoreDepth [label="CapFlux [mm]"];        
+    SoilWaterDepth ->KinematicWaveStore [label="ExfiltWaterCubic [m^3/s]"];
     "OutSide" -> UStoreDepth [label="ActInfilt [mm]"];
     UStoreDepth -> OutSide [label="ActEvapUStore [mm]"];
-    FirstZoneDepth -> OutSide [label="ActEvap-ActEvapUStore [mm]"];
-    FirstZoneDepth -> KinematicWaveStore [label="SubCellGWRunoffCubic [m^3/s]"];
+    SoilWaterDepth -> OutSide [label="ActEvap-ActEvapUStore [mm]"];
+    SoilWaterDepth -> KinematicWaveStore [label="SubCellGWRunoffCubic [m^3/s]"];
     "OutSide" -> KinematicWaveStore [label="SubCellRunoffCubic [m^3/s]"];
     "OutSide" -> KinematicWaveStore [label="RunoffOpenWater [m^3/s]"] ;
     "OutSide" -> KinematicWaveStore [label="FreeWaterDepthCubic [m^3/s]"] ;
Index: doc/wflow_sbm2.rst
===================================================================
diff -u -rd08f85b38e8de675a44c32721dd27a8818635b50 -r80ea4904654f975514dac4fb2258e48bfd880490
--- doc/wflow_sbm2.rst	(.../wflow_sbm2.rst)	(revision d08f85b38e8de675a44c32721dd27a8818635b50)
+++ doc/wflow_sbm2.rst	(.../wflow_sbm2.rst)	(revision 80ea4904654f975514dac4fb2258e48bfd880490)
@@ -5,6 +5,10 @@
 Introduction
 ------------
 
+.. info::
+
+    This documentation is incomplete it currently describes the original model
+
 The soil part of wflow\_sbm model follows the same concepts as the 
 topog\_sbm model. topog\_sbm is specifically designed to similate fast 
 runoff processes in small catchments while wflow\_sbm can be applied more