The drought here in TX has my husband's family knocking around ideas of setting up rainwater collection barrels at our homes. (three homes)

Last winter reminded us that it does indeed freeze in Texas, so we are stuck with a problem - if we are getting a bunch of rain in the fall, how do we keep it over the winter to last into the spring? Aside from the same kinds of precautions I could use that we do for our palm trees (cover as best we can, keep Christmas lights on to prevent freezing) is there a way of setting up a circulation pump, similar to our pool pump, so when we would be expecting freezing temps we could circulate water from the drain/tap back through the barrels?

This is the type of system we would make. http://www.emmitsburg.net/gardens/articles/adams/audrey/water_barrel.htm