The US Geological Survey's website hosts a wide range of hydrologic data products, including thematic map viewer options for the National Hydrography Data set; NHD Plus, and the Watershed Boundary Dataset (WBD): https://nhd.usgs.gov/data.html. Jacqueline V. Nolan Cartographer Library of Congress From: Maps-L: Map Librarians, etc. [mailto:[log in to unmask]] On Behalf Of Susan M Peschel Sent: Friday, December 08, 2017 11:54 AM To: [log in to unmask] Subject: Surface drainage information for Georgia We have a patron looking for a detailed hydrologic unit map for Forsyth County, GA (Cumming Quad) or something showing surface drainage for that particular area. Any suggestions would be appreciated. Susan Peschel AGS Library