A High Spatiotemporal Assessment of Consumptive Water Use and Water Scarcity in the Conterminous United States

There is an inextricable link between energy production and food/feed/fiber cultivation with available water resources. Currently in the United States, agriculture represents the largest sector of consumptive water use making up 80.7 % of the total. Electricity generation in the U.S. is projected to increase by 24 % in the next two decades and globally, the production of liquid transportation fuels are forecasted to triple over the next 25-years, having significant impacts on the import/export market and global economies. The tension between local water supply and demand across water use sectors needs to be evaluated with regards to risk evaluation and planning. To this end, we present a systematic method to spatially and temporally disaggregate nationally available 5-year county-scale water use data to a monthly 1/8° scale. Our study suggests that while 81.9 % of the U.S. exhibits unstressed local conditions at the annual scale, 13.7 % is considered water scarce; this value increases to 17.3 % in the summer months. The use of mean annual water scarcity at a coarser basin scale (~373,000 ha) was found to mask information critical for water planning whereas finer spatiotemporal scales revealed local areas that are water stressed or water scarce. Nationally, ~1 % of these “unstressed” basins actually contained water stressed or water scarce areas equivalent to at least 30 % and 17 %, respectively, of the basin area. These percentages increase to 34 % and 48 % in the summer months. Additionally, 15 % of basins classified as “unstressed” contained water scarce areas in excess of 10 % during the summer.