Swap order of elev model cleanup

ensembleperturbation/uncertainty_quantification/surrogate.py

@@ -673,10 +673,10 @@ def probability_field_from_surrogate(
         )
 
         # before evaluating prob. field for model set null water elevation to the ground elevation
+        training_set = numpy.fmax(training_set, -training_set['depth'])
         if minimum_allowable_value is not None:
             too_small = (training_set + training_set['depth']).values < minimum_allowable_value
             training_set.values[too_small] = numpy.nan
-        training_set = numpy.fmax(training_set, -training_set['depth'])
 
         ds1, ds2 = xarray.broadcast(training_set, surrogate_prob_field['level'])
         modeled_prob_field = (ds1 >= ds2).sum(dim='run') / len(training_set.run)