Originally Posted by FishinRod
DeerTexas,

...Finally, the size of the pond is not the sole controlling factor to avoid going dry during droughts. The pond actually needs to be "right sized" for the watershed area that drains into the pond combined with the annual rainfall amount. (That is only the first approximation. The slope of the land, cover vegetation, soil type and permeability, and several other factors are also important.) If your pond is too small for your drainage area, then a big rain can blow out your dam. If your pond is too large, then it will only be full during the peak of the rainy season, and will be low or dry during drought periods...

I'm not familiar with the Del Rio area, but I have spent some time in the Rio Grande/LaJitas area. Rod's correct about how rain can hit hard and heavy between droughts, and potentially blow out a pond. If possible, I'd avoid a slope for the pond, and try to build it on a low flat area. The same with water shed. A wide water shed can provide the same volume of water without getting pinched, and potentially causing funneled damage.

AL