Circle of Life

This spell enables a number of creatures to survive in arid, inhospitable terrain. Those affected by the spell need only half their water requirements per day, and regain 1 extra hit point every 24 hours.

The spell does not help the caster in any way, in fact, the caster requires twice the normal amount of water. The priest transfers his own bodily water to those within the circle of life, and the constant drain needs to be replenished.