One system that I saw was a system that I have seen used in my country all my life. This is a rain collecting system. In my country many of the homes have large tanks hung high in the trees above the house to collect rain water. This rain water is used to flush toilets, and even filtered to use in showers and sinks. This is now beginning to be a big thing in the States, where we are collecting rain water for many reasons. A system seen at the Go Expo was the Rain Pro. With this system there are many different possibilities. They show examples of small systems where your roof downspouts drain into tanks all the way up to 20,000 gallon tanks buried underground to collect the rain water. These systems can be used for irrigation, to flush toilets, to wash laundry, for fire protection, water for livestock, and just plain stewardship.
One inch of rain on a 2000 square foot roof will yield approximately 1200 gallons of water, and will yield approximately 52,000 gallons of per year based on 43 inches per year in the Triad area. If this system was installed in 100 locations it would yield over 5,000,000 gallons of water. This would also keep 5,000,000 gallons of water out of the storm drainage system. Having a water storage source in a drought condition, which we see here almost every year, could mean the difference in being able to water your lawn or wash your car at home or not. Even during a dry season, there are typically quick showers that can fill the tanks.
I believe this is a very important, and simple solution that should be considered in all new construction, and will probably see its way into the building code in the not too distant future.