Data on ground-water and surface-water use in Louisiana are available online in tabular form from the U.S. Geological Survey. Data are categorized by parish and by type of usage (e.g., public supply, irrigation, industry, and power generation) from 1960 to 2005. Water usage in Louisiana has complicated spatial and temporal trends which are not readily apparent in static tables. For example, ground-water usage varies from more than 200 million gallons a day in some rice farming parishes to less than 40,000 gallons a day in coastal parishes where most ground water is not potable. Baton Rouge Parish uses mostly ground water even though it is on the Mississippi River because the ground water is high quality. Orleans Parish uses almost exclusively river water because most ground water is brackish. Significant temporal trends include the rapid rise of water use for power generation since 1960, a drop in overall water usage during the economic downturn following the oil bust of the 1980s, and the switch from surface to ground water in some areas due to decadal droughts or pollution of surface water. Google Fusion Tables represent a rapid and effective way to visualize water usage trends for K–16 education, research, and public policy. Using Google API (application programming interface), we have developed intensity maps that illustrate quantity and category of both surface-water and ground-water use by parish. Each parish within an intensity map has a pop-up bar chart that shows total water usage from 1960 to 2005 in five-year increments. We also have included versions of intensity maps that have pop-up pie/line charts that show the distribution of usage in each parish among public supply, agriculture, industry, and power generation. The dynamic feature of Fusion Tables allows students, researchers, and policy makers to clearly see temporal trends as well as illustrate connections among water usage and other factors. For examples, most students falsely assume that the steady rise in water use for public supply is related to population increase whereas it is primarily due to a substantial increase in per capita usage. These tables will be made available on the web.