Merge branch 'peterdschwartz/lnd/add-endwb-restart-to-maint' (PR #6206)

Add endwb to ELM restart file in maint-2.0.

[BFB]
Fixes #6195

cime_config/testmods_dirs/allactive/wcprodssp/user_nl_elm

@@ -1,7 +1,7 @@
 ! fsurdat used is not the same file for the reference historical run (as recorded in elm.r's global attribute)
 
  CHECK_FINIDAT_FSURDAT_CONSISTENCY       = .false.
-
+ finidat = "$DIN_LOC_ROOT/e3sm_init/V2.SSP370_SSP585.ne30pg2_EC30to60E2r2/v2.LR.historical_0101/2015-01-01-00000/v2.LR.historical_0101.elm.r.noNaN.2015-01-01-00000.nc"
  hist_dov2xy = .true.,.true.
  hist_fincl2 = 'H2OSNO', 'FSNO', 'QRUNOFF', 'QSNOMELT', 'FSNO_EFF', 'SNORDSL', 'SNOW', 'FSDS', 'FSR', 'FLDS', 'FIRE', 'FIRA'
  hist_mfilt = 1,365

components/elm/src/data_types/ColumnDataType.F90

@@ -1698,7 +1698,7 @@ subroutine col_ws_restart(this, bounds, ncid, flag, watsat_input)
     ! Read/Write column water state information to/from restart file.
     !
     ! !USES:
-    use elm_varctl, only : use_lake_wat_storage
+    use elm_varctl, only : use_lake_wat_storage, do_budgets
     !
     ! !ARGUMENTS:
     class(column_water_state) :: this
@@ -1723,6 +1723,13 @@ subroutine col_ws_restart(this, bounds, ncid, flag, watsat_input)
        this%h2osfc(bounds%begc:bounds%endc) = 0.0_r8
     end if
 
+    if(do_budgets) then 
+       call restartvar(ncid=ncid, flag=flag, varname='ENDWB', xtype=ncd_double,  &
+         dim1name='column', &
+         long_name='water balance at end of timestep', units='kg/m2', &
+         interpinic_flag='interp', readvar=readvar, data=this%endwb)
+    end if 
+
     call restartvar(ncid=ncid, flag=flag, varname='H2OSOI_LIQ', xtype=ncd_double,  &
          dim1name='column', dim2name='levtot', switchdim=.true., &
          long_name='liquid water', units='kg/m2', &