If you have water frontage, your lot will get bigger .... and remember, whatever goes up must go down. Its part of the cycle although water usage in the area is expanding with increased population. The recent/current drought is not unique. It happens every so often. There are wet periods and dry periods. If for some reason, a wet period is skipped, we call it dry. If two are skipped, it's called a drought. It was probably worse in the 1950's but there wasn't the demand for water by people that there is now. There was however much greater demand by rice farmers but recently the LCRA stopped sending them water a couple of years ago. But don't worry, now that Lance has sold his house, the water level in Lake Travis should recover.
In all seriousness, water usage will be reduced per capita, either by increased cost or conscience, San Antonio had the same problem and has solved it by community awareness. Office complexes and retail centers may have to stop watering their grass. Golf courses may have to return to the maintenance levels of the 1950's when they just watered the greens. Once the population of Austin is 10 million people (probably about the time that New York City floods from the effects of Global Warming), there will still be enough water to cook, drink and bathe.