Index: /issm/trunk/m4/issm_options.m4
===================================================================
--- /issm/trunk/m4/issm_options.m4	(revision 4640)
+++ /issm/trunk/m4/issm_options.m4	(revision 4641)
@@ -190,6 +190,27 @@
 	AC_MSG_RESULT($HAVE_DAKOTA)
 	dnl %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%dakota-end%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-
-
+	
+	dnl %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%chaco-beginning%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+	AC_ARG_WITH([chaco-dir],
+			  AS_HELP_STRING([--with-chaco-dir = DIR], [chaco root directory.]),
+			 [CHACO_ROOT=$withval],[CHACO_ROOT=""]) 
+	AC_MSG_CHECKING(for Chaco )
+	
+	if test -d "$CHACO_ROOT"; then
+
+		dnl defaults
+		HAVE_CHACO=yes
+		CHACOINCL=-I$CHACO_ROOT/include
+		CHACOLIB="-L$CHACO_ROOT/lib -lchaco"
+
+		AC_DEFINE([_HAVE_CHACO_],[1],[with Chaco in ISSM src])
+		AC_SUBST([CHACOINCL])
+		AC_SUBST([CHACOLIB])
+
+	else
+		HAVE_CHACO=no
+	fi
+	AC_MSG_RESULT($HAVE_CHACO)
+	dnl %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%chaco-end%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%