USGS Water Data for the Nation Help
This help system is designed to assist you in rapidly finding relevant information about the USGS Water Data for the Nation web site (waterdata.usgs.gov).
If in a hurry, simply enter the search term in the search box and a list of related topics will be shown. You can also view frequently asked questions. A list of defined USGS search criteria and codes and parameters is also available. You can also learn about output formats.