'Groundwater Atlas of Lancaster County, Nebraska' available

            After two years of research, writing and editing, the first edition of "The Groundwater Atlas of Lancaster County, Nebraska" is complete and available to the public.

            "The atlas is based almost entirely on a relatively large amount of publicly available data, but a fair amount of work was required to identify and standardize the useful data," said Dana Divine, survey hydrogeologist in the Conservation and Survey Division of the University of Nebraska-Lincoln School of Natural Resources.

            Divine, along with cartographer Les Howard and editor Bob Diffendal, created maps, wrote text and compiled and interpreted data for topics that fell within their respective areas of expertise.

            About 30 of Nebraska's 93 counties have published some type of county-level groundwater report, although most of those were produced in the 1960s and 1970s. Despite a wealth of existing information, a county-wide groundwater report had not been previously published for Lancaster County, Divine said.

            "The atlas includes quite a bit of discussion regarding important features on the maps and how the maps were made, so that anyone with a bit of science background will learn something from reading it," she said. "Perhaps more importantly, all of the data sets, contours and error maps are available as ArcGIS files so the data can be viewed at different scales and incorporated into other studies."

            More than 1,000 wells in Lancaster County produce water exclusively from the Dakota aquifer, which is considered a secondary aquifer in eastern Nebraska since it's deeper than primary aquifers and the water quality can be salty or highly mineralized.

            "In recent years, especially since the 2012 drought, the Dakota aquifer has become the target aquifer for many new wells, despite the fact that relatively little information exists regarding the amount of water in storage, water quality or rate of recharge," Divine said. "The atlas includes a map of the water level in the Dakota aquifer and a map estimating minimum potential yield of the Dakota aquifer, both of which provide new information."

            The atlas also includes a compilation of chloride concentration data, most of which was provided by the Lower Platte South Natural Resources District and is especially important to irrigators and domestic well owners.

            "Nebraskans pride ourselves in the efficient use and management of groundwater as a shared and vital resource," Divine said. "The atlas is an attempt to answer many of the questions I'm asked regarding groundwater in the county, to support economic and personal decisions that residents make every day and to provide data to other professionals."

            "The Groundwater Atlas of Lancaster County, Nebraska" was produced by the Conservation and Survey Division, a multidisciplinary research, service and data-collection organization established by Nebraska state statute in 1921. The division also serves as the natural resource survey component of UNL's School of Natural Resources.

            The atlas and a CD-ROM of GIS files used to create the maps are $14 each and available for purchase from the Nebraska Maps and More Store on the first floor of Hardin Hall, 33rd and Holdrege streets. They can also be purchased online at http://nebraskamaps.unl.edu and http://www.amazon.com. To place an order by phone, call 402-472-3471.

Writer: Mekita Rivas, School of Natural Resources