Isibiyeli esinecala elinye yinkqubo yefom yokwenza ikhonkrithi yodonga lwecala elinye, olubonakaliswe ngamacandelo alo jikelele, ukwakhiwa okulula kunye nokusebenza okulula kunye nokukhawuleza. Ekubeni akukho ntonga yokubopha eludongeni, umzimba wodonga emva kokuphosa ungqinisiso lwamanzi ngokupheleleyo. Isetyenziswe ngokubanzi kudonga lwangaphandle lwendlu engaphantsi, iplanti yokucoca ugutyulo, umgaqo kaloliwe ohamba ngaphantsi komhlaba kunye nokhuseleko lwethambeka kwicala lendlela kunye nebhulorho.