I live in the country with farms all around. I have no ranches by me but just farms. With the corn and soybeans that my neighbor grows he is able to use the small river that is at the edge of his land to use as irrigation for the crops. I can tell when he is using it because  for one I can hear it down to my house. For another reason the corn and soybeans look so much better when it has not rained for awhile as right now. It has not rained good for about six weeks. But, with the irrigation from the river his crops look good. If you want to know more about water conservation check out  http://www.conserveranches.com/2008/06/12/ranches-using-irrigation-to-conserve-water.html