Use reasonable lake_option default when not specified

src/OrchestratorLayer/config.F90

@@ -476,6 +476,7 @@ subroutine rt_nlst_check(self)
    end if
 
    if ((self%lake_option .lt. 0) .or. (self%lake_option .gt. 3)) then
+      print *, self%lake_option
       call hydro_stop("Lake Option must be 0 [lakes off], 1 [level pool], or 2 [passthrough], or 3 [reservoir DA]")
    end if
 
@@ -669,7 +670,7 @@ subroutine init_namelist_rt_field(did)
     compound_channel = .FALSE.
     channel_loss_option = 0
     bucket_loss = 0
-    lake_option = 1
+    lake_option = -99
     reservoir_persistence_usgs = .FALSE.
     reservoir_persistence_usace = .FALSE.
     reservoir_observation_lookback_hours = 18
@@ -763,6 +764,15 @@ subroutine init_namelist_rt_field(did)
       lake_option = 1
     end if
 
+    if (lake_option == -99) then
+      if (route_lake_f /= "") then
+         print *, "WARNING: lake_option not specified, but route_lake_f specified. Setting lake_option to 1."
+         lake_option = 1
+      else
+         lake_option = 0
+      end if
+    end if
+
     nlst(did)%lake_option = lake_option
     nlst(did)%reservoir_persistence_usgs = reservoir_persistence_usgs
     nlst(did)%reservoir_persistence_usace = reservoir_persistence_usace