Pierre Sargent, U.S. Geological Survey, Lower Mississippi-Gulf Water Science Center, Baton Rouge Office, Suite 120, 3535 S. Sherwood Forest Blvd., Baton Rouge, LA, 70816: firstname.lastname@example.org, Robert B. Fendick, U.S. Geological Survey, Lower Mississippi-Gulf Water Science Center, Baton Rouge Office, Suite 120, 3535 S. Sherwood Forest Blvd., Baton Rouge, LA 70816: email@example.com, and Angela L. Collier, U.S. Geological Survey, Lower Mississippi-Gulf Water Science Center, Baton Rouge Office, Suite 120, 3535 S. Sherwood Forest Blvd., Baton Rouge, LA 70816: firstname.lastname@example.org
The U.S. Geological Survey’s Groundwater Watch (http://groundwaterwatch.usgs.gov/) is a web-based product that displays networks of wells in addition to location maps, hydrographs, statistical summaries, and other details. Data are provided to Groundwater Watch using the U.S. Geological Survey National Water Information System’s publically accessible database, NWISWeb. Water-level measurements are uploaded to NWISWeb on a regular basis, as frequently as hourly. State and parish maps on Groundwater Watch provide a local picture of groundwater conditions. Individual web pages provide details about a specific well, and all available water-level data from the well.
The U.S. Geological Survey, in cooperation with several State and local agencies, has estimated groundwater withdrawals in Louisiana since 1960 and has monitored groundwater levels in Louisiana’s aquifers since the early 1900s. In 2013, about 1,635 million gallons per day of groundwater was withdrawn from 13 major aquifers and aquifer systems Louisiana. This is an increase in withdrawals of 62 million gallons per day or about 4 percent from the year 2000. Water-level trends in Louisiana’s aquifers and aquifer systems were compared to withdrawals for the years 2000, 2005, 2010, 2012, and 2013.
Groundwater levels in Louisiana’s aquifers respond to changes in groundwater withdrawal rates. Although water-level monitoring can provide water-level condition and trend information about an aquifer, the complexity of groundwater flow systems in Louisiana makes comparison difficult with associated withdrawal data. Discontinuities and lateral and vertical anisotropy within an aquifer can make it difficult to infer water-level conditions for the entire aquifer from water levels at a few monitor wells. However, by coupling water-use information with extensive water-level data, and having an awareness of system complexity, assessments can be made that can be used in groundwater resource management.
Key words; groundwater, water level, water use, Louisiana