Amanda T. Flynn Jennifer S. Stanton Moussa Guira 20180101 groundwater model Reston, VA, USA U.S. Geological Survey https://doi.org/10.5066/P9RITFNL Amanda T. Flynn Jennifer S. Stanton 2018 Publication Scientific Investigations Report 2018-5106 Reston, VA, USA U.S. Geological Survey https://doi.org/10.3133/sir20185106 The U.S. Geological Survey (USGS) refined the spatial and temporal discretization of a previously modeled area (Phase 1: https://pubs.usgs.gov/sir/2008/5143/ and Phase 2: https://pubs.usgs.gov/sir/2010/5149/) which focused on a 30,000-square-mile area of the High Plains aquifer. Regional groundwater-flow models were constructed to evaluate the effects of groundwater withdrawal on stream base flow in the Elkhorn and Loup River Basins, Nebraska. The model was calibrated to match groundwater level and base-flow data from the stream-aquifer system during the pre-1940 through 2010 period (including predevelopment [pre-1895], early development [1895–1940], and historical development [1940 through 2010] conditions) using an automated parameter- estimation method. The calibrated model was then used to simulate hypothetical development conditions (2011 through 2060). To assess the impact of wells on aquifer depletions, additional wells were simulated throughout the model domain and pumped for 50 years. The percentage of each well’s withdrawal after 50 years, which was compensated by aquifer reductions to stream base flow, storage, or evapotranspiration, was computed and mapped. This data release also includes the MODFLOW-NWT (version 1.0.7) source code. This USGS data release contains all of the input and output files for the model described in the associated model documentation report (https://doi.org/10.3133/sir20185106). This groundwater model was created to characterize groundwater resources and the interaction of groundwater with streams and other hydrologic features within Central Nebraska. The development of the model input and output files included in this data release are documented in U.S. Geological Survey Scientific Investigations Report 2018-5106 (https://doi.org/10.3133/sir20185106). Support is provided for correcting errors in the data release and clarification of the modeling conducted by the U.S. Geological Survey. Users are encouraged to review the model documentation report (https://doi.org/10.3133/sir20185106) to understand the purpose, construction, and limitations of this model. The models will run successfully only if the original directory structure is correctly restored. The model archive is broken into several pieces to reduce the likelihood of download timeouts. Instructions for reconstructing the original directory structure and running the models included in this data release and described in the model documentation report can be found in the readme.txt ASCII file which can be downloaded as part of this data release. The .zip files associated with the release were compressed using WinRAR. It would be advisable to use WinRAR to uncompress these files. 18950101 20101231 publication date Complete Not planned -102.142168073 -97.251923792 42.959968000 40.581077344 USGS Thesaurus usgsgroundwatermodel MODFLOW-NWT Groundwater InlandWaters Groundwater Model Soil-Water-Balance Code Streamflow depletion ISO 19115 Topic Category geoscientificInformation inlandWaters environment USGS Metadata Identifier USGS:e812b36d-631c-49c2-9c7d-6873be715bdb Geographic Names Information System Nebraska Sand Hills Loup River Elkhorn River Ogallala Aquifer High Plains Aquifer None. Acknowledgement of the U.S. Geological Survey would be appreciated in products derived from this data release. none. Users are advised to read the data set's metadata thoroughly to understand appropriate use and data limitations. Amanda T. Flynn U.S. Geological Survey Mailing and Physical

5231 S 19 St

Lincoln NE 68512 USA 402-328-4100 aflynn@usgs.gov https://www.sciencebase.gov/catalog/file/get/631405d0d34e36012efa33c7?name=sir2018-5106thumbnail.jpg Image of the model domain and active area of the model. jpg U.S. Geological Survey Water Availability and Use Science Program and the Lewis and Clark, Lower Elkhorn, Lower Loup, Lower Platte North, Lower Niobrara, Middle Niobrara, Upper Elkhorn, and Upper Loup Natural Resources Districts None Unclassified None Environment as of Metadata Creation: Microsoft [Unknown] Version 6.2 (Build 9200) ; Esri ArcGIS 10.5.1 (Build 7333) Service Pack N/A (Build N/A) Steven M. Peterson Jennifer S. Stanton Amanda T. Saunders Jesse R. Bradley 2008 Publication Scientific Investigations Report 2008–5143 Reston, VA, USA U.S. Geological Survey https://pubs.usgs.gov/sir/2008/5143/ Jennifer S. Stanton Steven M. Peterson Michael N. Fienen 2008 Publication Scientific Investigations Report 2010–5149 Reston, VA, USA U.S. Geological Survey https://pubs.usgs.gov/sir/2010/5149/ The model was calibrated using PEST (Doherty, 2016a), a parameter estimation suite of software. The 1940s data was used to simulate historical conditions prior to 1940 (predevelopment). The automated calibration process was constrained by (1) water-level data from 1,467 wells for predevelopment and 6,845 wells for the development time period (1940 to 2010) and (2) 38 stations with estimated base flow for predevelopment and 51 station with estimated base flow for the development period. No formal logical accuracy tests were conducted Data set is considered complete for the information presented, as described in the abstract. Users are advised to read the rest of the metadata record and the associated model documentation report (https://doi.org/10.3133/sir20185106) for additional details. No formal positional accuracy tests were conducted No formal positional accuracy tests were conducted The process used to develop, calibrate, and apply the model is fully described in the model documentation reports (Phase 1: https://pubs.usgs.gov/sir/2008/5143/), (Phase 2: https://pubs.usgs.gov/sir/2010/5149/) and (Phase 3: https://doi.org/10.3133/sir20185106). 2018 raster pixel Lambert Conformal Conic 40.0 43.0 -100.0 39.83333333333334 1640416.666666667 0.0 row and column 2640 2640 feet North American Vertical Datum of 1988 1.0 feet Attribute values SIR2018_5106.shp ESRI Polygon shapefile U.S. Geological Survey Area Text string indicating is polygon area is active or inactive in the model. https://doi.org/10.3133/sir20185106 usgsgroundwatermodel Delineation of active and inactive areas in the model. https://doi.org/10.3133/sir20185106 Flynn, A.T., Stanton, J.S., and Guira, Moussa, 2018, MODFLOW-NWT groundwater flow model used to evaluate groundwater flow in the Elkhorn and Loup River Basins, Central Nebraska, Phase Three: U.S. Geological Survey data release https://doi.org/10.5066/P9RITFNL U.S. Geological Survey GS ScienceBase mailing address

Denver Federal Center, Building 810, Mail Stop 302

Denver CO 80225 United States 1-888-275-8747 sciencebase@usgs.gov The data have been approved for release by the U.S. Geological Survey (USGS). Although the data have been subjected to rigorous review and are substantially complete, the USGS reserves the right to revise the data pursuant to further analysis and review. Furthermore, the data are released on the condition that neither the USGS nor the U.S. Government shall be held liable for any damages resulting from authorized or unauthorized use. Although the data, software, and related material have been processed successfully on a computer system at the USGS, no warranty expressed or implied is made regarding the display or utility of the data for other purposes, nor on all computer systems, nor shall the act of distribution constitute any such warranty. The USGS or the U.S. Government shall not be held liable for improper or incorrect use of the data described and/or contained herein. Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Digital Data https://doi.org/10.5066/P9RITFNL None 20201117 U.S. Geological Survey Water Mission Area mailing

12201 Sunrise Valley Dr

Reston VA 20192 GS-W-model-data@usgs.gov FGDC Content Standard for Digital Geospatial Metadata FGDC-STD-001-1998