Since the winter picture was taken two of my hens have been killed, likely by raccoons. We had 3 years without such death so it was a bit shocking. Led to the discovery of weak spots/holes in our coop that I chalk up to entropy, but now believe are fixed. Teaches kids about death and the attention to detail needed to prevent it sometimes.

I don't know where Jason is, but it doesn't rain at all in most of California during May-September, during which our water generally comes from melting snowpack in the Sierras, Colorado River, etc. But thanks for the good thought.

I hope the following is useful to someone in South Texas, although it may not be the most encouraging reading.

You might want to look at the recent conference in Austin, Climate Change Impacts on Texas Water. The Proceedings includes Texas Water and Warming, esp. p.23-, and The Changing Climate of South Texas 1900-2100.

The answer to animal housing in very hot climates is earth sheltered housing. The easiest is to build arches out of some type of masonry and then cover them with a couple feet of earth (dirt).
The deeper the earth cover the better. The temperature at 6-8 feet below ground is usually a constant high 60's in hot climates. So the closer you get to that much earth cover the closer to that constant temperature in your housing.
The housing has to big enough to be able to absorb the heat given off by the animals and still maintain a stable temperature.

I would also recommend getting some books on rain water collection and storage. A lot of very dry places in Mexico are able to collect and store enough rain water from the few storms they do get to last the entire community for the rest of the year. Most of the large storage systems are ferro-cement - which can be easily done in homeowner scale by the average person.