diff --git a/cime_config/buildnml b/cime_config/buildnml
index 44f24ea..56c8cb7 100755
--- a/cime_config/buildnml
+++ b/cime_config/buildnml
@@ -52,6 +52,7 @@ def _create_namelists(case, confdir, inst_string, infile, nmlgen, data_list_path
            else:
                logger.warning( "WARNING::"+message )
 
+    config['mosart_flood_mode'] = case.get_value("MOSART_FLOOD_MODE")
     config['rof_grid'] = case.get_value("ROF_GRID")
     config['lnd_grid'] = case.get_value("LND_GRID")
     config['rof_ncpl'] = case.get_value("ROF_NCPL")
diff --git a/cime_config/config_component.xml b/cime_config/config_component.xml
index ce5fbf1..84b4619 100644
--- a/cime_config/config_component.xml
+++ b/cime_config/config_component.xml
@@ -14,7 +14,7 @@
     <desc option="FLOOD">MOSART model with flood:</desc>
   </description>
 
-  <entry id="COMP_ROF">
+  <entry id="COMP_ROF"> 
      <type>char</type>
      <valid_values>mosart</valid_values>
      <default_value>mosart</default_value>
@@ -44,6 +44,18 @@
     <desc>If warnings in namelist setttings from buildnml should be ignored or not</desc>
   </entry>
 
+  <entry id="MOSART_FLOOD_MODE">
+    <type>char</type>
+    <valid_values>ACTIVE,NULL</valid_values>
+    <default_value>NULL</default_value>
+    <values>
+      <value compset="_MOSART%FLOOD">ACTIVE</value>
+    </values>
+    <group>build_component_mosart</group>
+    <file>env_build.xml</file>
+    <desc>mode for mosart flood feature, NULL means mosart flood is turned off</desc>
+  </entry>
+
   <entry id="MOSART_SIM_YEAR">
     <type>char</type>
     <valid_values></valid_values>
diff --git a/cime_config/namelist_definition_mosart.xml b/cime_config/namelist_definition_mosart.xml
index 556192c..f8843ef 100644
--- a/cime_config/namelist_definition_mosart.xml
+++ b/cime_config/namelist_definition_mosart.xml
@@ -8,6 +8,20 @@
   <!-- MOSART Namelist -->
   <!-- ========================================================================================  -->
 
+  <entry id="do_rtmflood" modify_via_xml="MOSART_FLOOD_MODE">
+    <type>logical</type>
+    <category>mosart</category>
+    <group>mosart_inparm</group>
+    <values>
+      <value mosart_flood_mode="ACTIVE">.true.</value>
+      <value mosart_flood_mode="NULL">.false.</value>
+    </values>
+    <desc>
+      If .true., turn on mosart flooding back to clm
+      Note that mosart flood is not supported in CESM1.1
+    </desc>
+  </entry>
+
   <entry id="ice_runoff">
     <type>logical</type>
     <category>mosart</category>