Conservation programs may be ultimately necessary simply to counteract an exogenous long-term increase in residential uses. Climate affects residential use in predictable ways. Water use is strongly correlated with average monthly temperature and seasonal variation in temperature. Precipitation was consistently insignificant in all models. All cities in this analysis are semi-arid to arid in climate, and thus the ratio of evapotranspiration to precipitation is much greater.
Landscape watering is necessary if one wants to maintain traditional residential lawns and trees.
Random and infrequent rains don't change residential watering patterns to a significant degree. Other variables, such as residential income and the size of the city, also vary but their influence is estimated to have a relatively minor impact on residential use. In summary, price and nonprice conservation programs are effective, but require a major commitment to implement. Consumers are very unresponsive to price increases under current rate structures, requiring large increases in price to achieve small reductions in demand. Nonprice conservation programs appear to be most effective when there are a substantial number of programs conducted over longer periods of time.