WLAY1 = SWET(ChNo,SFCLY) * VGWMAX(SFCLY,ITYP(ChNo))

      SWET(ChNo,SFCLY) = (WLAY1 - ELAY1) / VGWMAX(SFCLY,ITYP(ChNo))

      SWET(ChNo,SFCLY)  = MIN( 1. _d 0, MAX( 0. _d 0, SWET(ChNo,SFCLY) )

        SWET(ChNo,SFCLY) = SWET(ChNo,SFCLY) +

     &                         THRU / VGWMAX(SFCLY,ITYP(ChNo))

        IF ( SWET(ChNo,SFCLY) .GT. 1. ) THEN

          DEWRUN = ( SWET(ChNo,SFCLY) - 1. ) * VGWMAX(SFCLY,ITYP(ChNo))

          SWET(ChNo,SFCLY) = 1.

      ZDEP12 = VGZDEX(SFCLY,ChNo) + VGZDEX(ROOTLY,ChNo)

      IF( SWET(CHNO,SFCLY) .GT. WETEQ1(CHNO) ) THEN

          FAREA=(SWET(CHNO,SFCLY) - WETEQ1(CHNO)) / (1. - WETEQ1(CHNO))

          DHDZ = 1. + 2.*(PHLAY(ChNo,SFCLY)-PHLAY(ChNo,ROOTLY))/ZDEP12

      HALFMX=0.5*ABS( SWET(CHNO,SFCLY)-WETEQ1(CHNO) )

     &                               * WSMAX(SFCLY,ITYP(CHNO))

     &               SWET(ChNo,SFCLY) * WSMAX(SFCLY,ITYP(ChNo)) )

          GWFLUX = -MIN( ABS(GWFLUX),   WSMAX(SFCLY,ITYP(ChNo)) -

     &                SWET(ChNo,SFCLY) * WSMAX(SFCLY,ITYP(ChNo)) )

      SWET(ChNo,SFCLY) = SWET(ChNo,SFCLY) -

     &                        GWFLUX / WSMAX(SFCLY,ITYP(ChNo))

      VGZDEX(SFCLY ,ChNo) = VGZDEP(SFCLY ,ITYP(ChNo))

      SWET(ChNo,SFCLY ) = max( min(SWET1(ChNo),1. _d 0), 0. _d 0)

      WSOI12=SWET(ChNo,SFCLY ) * VGWMAX(SFCLY ,ITYP(ChNo)) +

     &          (VGWMAX(SFCLY,ITYP(ChNo)) + VGWMAX(ROOTLY,ITYP(ChNo)))

     I             NCH, UM, U2FAC, Z2, RDC, SWET(1,SFCLY),

      CALL RSURFP (NCH, UM, U2FAC, Z2, RDC, SWET(1,SFCLY),

      CALL RSURFP (NCH, UM, U2FAC, Z2, RDC, SWET(1,SFCLY),

     I             NCH,          ITYP,        SWET (1, SFCLY), VGBEEX,

     O             PHLAY(1,SFCLY), AKLAY(1,SFCLY),  DUMMY

      SWET1(ChNo) = SWET(ChNo,SFCLY)

      INTEGER  NLAY, SFCLY, ROOTLY, RECHLY

      PARAMETER (SFCLY = 1, ROOTLY = SFCLY + 1, RECHLY = ROOTLY + 1)