Tearing out our lawns is a good start toward wiser water use in Southern California, but it’s not enough.

To do the job properly, we must also be ready to collect the rain that will someday fall out of the sky, advocates say. And these people have a vision that not only stores increasingly precious rainwater, but puts it to use for everything from drip irrigation to aquaculture to waterfalls surrounded by lush plantings and the soothing music of running (albeit recycled) water.