--- a/flys-artifacts/src/main/java/de/intevation/flys/artifacts/model/FlowVelocityCalculation.java	Sun Sep 16 17:55:10 2012 +0000
+++ b/flys-artifacts/src/main/java/de/intevation/flys/artifacts/model/FlowVelocityCalculation.java	Sun Sep 16 18:42:20 2012 +0000
@@ -1,18 +1,21 @@
 package de.intevation.flys.artifacts.model;
 
 import java.util.ArrayList;
+import java.util.Collections;
 import java.util.List;
 
-import org.apache.log4j.Logger;
+import de.intevation.artifacts.Artifact;
 
-import de.intevation.artifacts.Artifact;
+import de.intevation.flys.artifacts.access.FlowVelocityAccess;
+
+import de.intevation.flys.artifacts.model.RiverFactory;
+
 import de.intevation.flys.model.DischargeZone;
 import de.intevation.flys.model.FlowVelocityModel;
 import de.intevation.flys.model.FlowVelocityModelValue;
 import de.intevation.flys.model.River;
 
-import de.intevation.flys.artifacts.access.FlowVelocityAccess;
-import de.intevation.flys.utils.FLYSUtils;
+import org.apache.log4j.Logger;
 
 
 public class FlowVelocityCalculation extends Calculation {
@@ -80,7 +83,17 @@
         FlowVelocityAccess  access,
         List<DischargeZone> zones
     ) {
-        River river = FLYSUtils.getRiver(access.getArtifact());
+        String riverName = access.getRiver();
+        if (riverName == null) {
+            logger.warn("No river name found");
+            return Collections.<FlowVelocityModel>emptyList();
+        }
+
+        River river = RiverFactory.getRiver(riverName);
+        if (river == null) {
+            logger.warn("No such river: " + riverName);
+            return Collections.<FlowVelocityModel>emptyList();
+        }
 
         List<FlowVelocityModel> models = new ArrayList<FlowVelocityModel>();