diff --git a/include/world_builder/world.h b/include/world_builder/world.h
index 0627eb60d..85f0a6155 100644
--- a/include/world_builder/world.h
+++ b/include/world_builder/world.h
@@ -92,15 +92,24 @@ namespace WorldBuilder
        *
        * Composition is identified by 2. This produces one
        * value in the output. The second entry  identifies the composition number and the third
-       * number is not used. So a commposition query asking about composition 1 looks like this:
+       * number is not used. So a composition query asking about composition 1 looks like this:
        * {2,1,0}. A composition query prodoces one entry in the output vector.
        *
-       * Grains are identified by 2. The second entry is the grain composition number and the third
+       * Grains are identified by 3. The second entry is the grain composition number and the third
        * entry is the number of grains. A query about the grains, where it asks about composition 1
-       * (for example enstatite) and 500 grains, looks like this: {2,1,500}.
+       * (for example enstatite) and 500 grains, looks like this: {3,1,500}.
        * A composition query prodoces n_grains*10 entries in the output vector. The first n_grains
        * entries are the sizes of all the grains, and the other 9 entries are sets of rotation
        * matrices. The rotation matrix entries are ordered [0][0],[0][1],[0][2],[1][0],[1][1],etc.
+       *
+       * The tag is identified by 4 and no extra information is needed. So the tag
+       * input usually looks like {4,0,0}. A tag query produces one entry in the output
+       * vector, representing the index of the tag of the last/dominant feature.
+       *
+       * The velocity is identified by 5 and no extra information is needed. So the tag
+       * input usually looks like {5,0,0}. A tag query produces three entry in the output
+       * vector, representing the x, y and z velocity, even in 2D. In 2D the velocies are
+       * projected on the 2D plane, and the 3rd velocity element will be zero.
        */
       std::vector<double> properties(const std::array<double, 2> &point,
                                      const double depth,
@@ -131,8 +140,13 @@ namespace WorldBuilder
        * matrices. The rotation matrix entries are ordered [0][0],[0][1],[0][2],[1][0],[1][1],etc.
        *
        * The tag is identified by 4 and no extra information is needed. So the tag
-       * input usually looks like {4,0,0}. A tag query prodoces one entry in the output
+       * input usually looks like {4,0,0}. A tag query produces one entry in the output
        * vector, representing the index of the tag of the last/dominant feature.
+       *
+       * The velocity is identified by 5 and no extra information is needed. So the tag
+       * input usually looks like {5,0,0}. A tag query produces three entry in the output
+       * vector, representing the x, y and z velocity, even in 2D. In 2D the velocies are
+       * projected on the 2D plane, and the 3rd velocity element will be zero.
        */
       std::vector<double> properties(const std::array<double, 3> &point,
                                      const double depth,
diff --git a/source/world_builder/world.cc b/source/world_builder/world.cc
index 3fa7b6d30..910b8973e 100644
--- a/source/world_builder/world.cc
+++ b/source/world_builder/world.cc
@@ -306,12 +306,11 @@ namespace WorldBuilder
 
     const std::array<double, 3> point_3d_cartesian = this->parameters.coordinate_system->natural_to_cartesian_coordinates(coord_3d.get_array());
 
-    // Todo: convert 3d velocity to 2d velocity
     std::vector<double> results = this->properties(point_3d_cartesian, depth, properties);
     unsigned int counter = 0;
-    for (unsigned int i = 0; i < properties.size(); ++i)
+    for (auto property : properties)
       {
-        switch (properties[i][0])
+        switch (property[0])
           {
             case 1:   // temperature
             {
@@ -337,13 +336,8 @@ namespace WorldBuilder
             {
               // convert 3d velocity vector to a 2d one
               Point<2> vector = Point<2>(cartesian);
-              //vector[0] = (results[counter]-cross_section[0][0])/surface_coord_conversions[0];
-              //vector[1] = results[counter+2];
               vector[0] = surface_coord_conversions[0]*results[counter]+surface_coord_conversions[1]*results[counter+1];
               vector[1] = results[counter+2];
-              //vector[2] = 0;
-              //if(vector.norm_square() > delaunator::EPSILON)
-              //  std::cout << counter << ": case 5: vec = " << vector << ", ("<< results[counter] << ":" << results[counter+1] << ":" << results[counter+2] << ")" << ", results[counter] = " << results[counter] << ", cross_section[0][0] = " << cross_section[0][0] << ", surface_coord_conversions[0] = " << surface_coord_conversions[0] << ", 2nd: " << ", cross_section[0][1] = " << cross_section[0][1] << ", surface_coord_conversions[1] = " << surface_coord_conversions[1]<< std::endl;
               results[counter] = surface_coord_conversions[0]*results[counter]+surface_coord_conversions[1]*results[counter+1];
               results[counter+1] = results[counter+2];
               results[counter+2] = 0;
@@ -352,15 +346,15 @@ namespace WorldBuilder
             }
             default:
             {
-              WBAssertThrow(false,
-                            "Internal error: Unimplemented property provided. " <<
-                            "Only temperature (1), composition (2), grains (3), tag (4) or velocity (5) are allowed. "
-                            "Provided property number was: " << properties[i][0]);
+              WBAssert(false,
+                       "Internal error: Unimplemented property provided by internal process. " <<
+                       "Only temperature (1), composition (2), grains (3), tag (4) or velocity (5) are allowed. "
+                       "Provided property number was: " << property[0]);
             }
           }
 
       }
-    return results;//this->properties(point_3d_cartesian, depth, properties);
+    return results;
   }