Index: wflow-py/wflow/wflow_delwaq.py
===================================================================
diff -u -rdcb879ddd956f6091ebadc68fb924e6502f26d5f -rcf5bc2e998754e9e149565c87ceb1083a3cefb9a
--- wflow-py/wflow/wflow_delwaq.py	(.../wflow_delwaq.py)	(revision dcb879ddd956f6091ebadc68fb924e6502f26d5f)
+++ wflow-py/wflow/wflow_delwaq.py	(.../wflow_delwaq.py)	(revision cf5bc2e998754e9e149565c87ceb1083a3cefb9a)
@@ -983,11 +983,12 @@
     f.close()
 
 
-def dw_WriteSurfaceFile(fname,m,n,noseg,block):
+def dw_WriteSurfaceFile(fname,block):
     """
     Generates a Delwaq surface (*.srf) file.
     """
     f = open(fname, 'wb')
+    f.write(struct.pack('i',0))
     f.write(struct.pack('%if'%len(block), *block))
     f.close()
 
@@ -1287,7 +1288,7 @@
     comroot = os.sep.join([dwdir,'com',runId])
     mmax, nmax = dw_GetGridDimensions(ptid)
     dw_WritePointer(comroot+'.poi',pointer,binary=True)
-    dw_WriteSurfaceFile(comroot+'.srf',mmax,nmax,NOSQ,surface_block)
+    dw_WriteSurfaceFile(comroot+'.srf',surface_block)
     dw_WriteSegmentOrExchangeData(0,comroot+'.len',length_block,1,WriteAscii)
     
     logger.info("Writing waq geometry file")