Factors governing change in water withdrawals for U.S. industrial sectors from 1997 to 2002.

The United States Geological Survey (USGS) reports that U.S. water withdrawals have been steady since 1980, but the population and economy have grown since then. This implies that other factors have contributed to offsetting decreases in water withdrawals. Using water withdrawal data from USGS and economic data from Bureau of Economic Analysis (BEA), direct and total water withdrawals were estimated for 134 industrial summary sectors in the 1997 U.S. economic input-output (EIO) table and 136 industrial sectors in the 2002 EIO table. Using structural decomposition analysis (SDA), the change in water withdrawals for the economy from 1997 to 2002 was allocated to changes in population, GDP per capita, water use intensity, production structure, and consumption patterns. The changes in population, GDP per capita, and water use intensity led to increased water withdrawals, while the changes in production structure and consumption patterns decreased water withdrawals from 1997 to 2002. Consumption patterns change was the largest net contributor to the change in water withdrawals. The model was used to predict aggregate changes in total water withdrawals from 2002 to 2010 due to known changes in population and GDP per capita; a more complete model assessment must await release of updated data on USGS water withdrawals and EIO data.