The costs and mortal dangers of unauthorized migrations as a limiting rationing device. Is there a better solution?

In face of the present migratory pressures from the poor towards the richer countries, and of the present framework of international humanitarian law, the costs and dangers of unauthorized migrations appear to act as a rationing device restricting actual migrations to a small fraction of their very large potential. However ethically abhorrent this appears to be, in practice it is the only effective limiting factor to mass immigration that is allowed by international law. Perhaps something is wrong with international law.