Seasonality and water demand

From Water Wiki

Water demand in the southeastern United States is greatly driven by seasonal irrigation -- largely the irrigation of home and commercial landscapes during the summer. The "peaks" in demand caused by this single use are primary drivers of a water system's capacity requirements. Any policy measures that can "shave" these peaks (such as landscape design that requires less or no irrigation) have great potential for improving the efficiency of water use in the southeast.

Here, for example, is a chart of the Town of Cary's water demand over four years, from 2001-2005. Note the annual peaks for residential use--primarily from outdoor watering.