Of the approximately 6.6 million people living in the Mississippi embayment (MISE) region in the central United States, approximately 65 percent rely on groundwater for their drinking water (Dieter, Linsey, and others, 2017). Regional assessments of water quality in principal aquifer systems provide context for the long-term availability of these water resources for drinking-water supplies. To assess the current (2018) status of water quality in MISE in relation to drinking water supplies, groundwater withdrawal zones used for domestic and public supply were modeled using available groundwater well and hydrogeologic framework data. Three dimensional surfaces were modeled to map the depth zones at which groundwater is withdrawn for drinking water. These surfaces will be used to model groundwater quality as part of the U.S. Geological Survey National Water Quality Assessment project’s intensive principal aquifer analysis. The MISE region includes two principal aquifer systems: the surficial aquifer system, which is dominated by the Quaternary Mississippi River Valley Alluvial aquifer (MRVA), and the Mississippi embayment aquifer system, which includes deeper Tertiary aquifers and confining units. Based on the distribution of groundwater use for drinking water, the modeling effort is focused on MRVA and two hydrogeologic units from the deeper system, including the middle Claiborne aquifer (MCAQ) and lower Claiborne aquifer (LCAQ). The MRVA is a surficial, unconfined to semi-confined, highly productive aquifer used mostly for irrigation, with a lesser amount of groundwater use for public supply and domestic self-supply (Clark and others, 2011; Maupin and Barber, 2005). The median thickness of the MRVA is about 130 feet (ft) but it can be as much as 290 ft thick (Hart and others, 2008). The MCAQ is confined where overlain by the Middle Claiborne confining unit and is used dominantly for public supply. Domestic self-supply occurs along outcrop areas where the unit is shallower or crops out. The unit consists mostly of the Sparta Sand, but north of approximately the 35th parallel (near the border between Tennessee and Mississippi), the underlying lower Claiborne confining unit (LCCU) undergoes a facies change and the Memphis Sand is included in the MCAQ (Hosman and Weiss, 1991). The MCAQ has a median thickness of about 805 ft, but it can be as much as 1,890 ft thick (Hart and others, 2008). Although not as regionally important as MRVA or MCAQ, domestic and public supply wells withdraw groundwater from LCAQ, especially on the margins of the Mississippi embayment where LCAQ is relatively shallow or crops out. The aquifer does not extend north of approximately the 35th parallel because of a facies change in the LCCU. The aquifer is relatively thin, ranging from 50 to 195 ft thick with a median thickness of 125 ft (Hart and others, 2008). Continuous surfaces representing groundwater withdrawal zones used for drinking water were created for MRVA (combined domestic and public supply), MCAQ-domestic, MCAQ-public supply, LCAQ-domestic, and LCAQ-public supply, where the surfaces represent the altitude (in feet above North American Vertical Datum of 1988) of the bottom and top of the screened interval. Surfaces were created by kriging well points using Empirical Bayesian Kriging in ArcMap version 10.4 (ESRI, 2016). Well construction information for public supply (P) and domestic (D) wells and aquifer surfaces from the Mississippi Embayment hydrogeologic framework (Hart and others, 2008) were used to populate as much information as available about well use, well depth, screened interval, and aquifer as to improve the modeled surfaces. To assess error on the modeled surfaces, well datasets were separated into training (90 percent) and testing (10 percent) datasets for kriging and root mean square error was calculated. The number of wells used for kriging varied for each surface (WellsSummary.csv). A shapefile representing the density of wells

This dataset contains a zipped file of 19 shapefiles that present the lands permitted to withdraw groundwater for aquaculture and irrigation use from the Mississippi River Valley Alluvial Aquifer in the Mississippi Delta each year from 1999 through 2017. The polygons in this dataset were provided by the Mississippi Department of Environmental Quality.

This dataset contains a zipped file of 19 shapefiles that present the lands permitted to withdraw groundwater for aquaculture and irrigation use from the Mississippi River Valley Alluvial Aquifer in the Mississippi Delta each year from 1999 through 2017. The polygons in this dataset were provided by the Mississippi Department of Environmental Quality.

This dataset contains a zipped file of 19 shapefiles that present the lands permitted to withdraw groundwater for aquaculture and irrigation use from the Mississippi River Valley Alluvial Aquifer in the Mississippi Delta each year from 1999 through 2017. The polygons in this dataset were provided by the Mississippi Department of Environmental Quality.

This dataset contains a zipped file of 19 shapefiles that present the lands permitted to withdraw groundwater for aquaculture and irrigation use from the Mississippi River Valley Alluvial Aquifer in the Mississippi Delta each year from 1999 through 2017. The polygons in this dataset were provided by the Mississippi Department of Environmental Quality.

This dataset contains a zipped file of 19 shapefiles that present the lands permitted to withdraw groundwater for aquaculture and irrigation use from the Mississippi River Valley Alluvial Aquifer in the Mississippi Delta each year from 1999 through 2017. The polygons in this dataset were provided by the Mississippi Department of Environmental Quality.

Groundwater is an often overlooked freshwater resource compared to surface water, but groundwater is used widely across the United States, especially during periods of drought. If groundwater models can successfully simulate past conditions, they may be used to evaluate potential future pumping scenarios or climate conditions, thus providing a valuable planning tool for water-resource managers. Quantifying the groundwater-use component for a groundwater model is a vital but often challenging endeavor. This dataset includes groundwater withdrawal rates modeled for the Ozark Plateaus aquifer system (Ozark system) from 1900 to 2010 by county for domestic water use. Public supply, non-agriculture, livestock, and agriculture groundwater withdrawal rates are available in the complementary dataset “Public supply, non-agriculture, livestock, and agriculture groundwater withdrawal rates from the Ozark Plateaus aquifer system, 1900 to 2010”. The Ozark system is located in the central United States and is composed of interbedded Cambrian to Pennsylvanian clastic and carbonate lithologies. In stratigraphic order, the Ozark system includes the Basement confining unit, St. Francois aquifer, St. Francois confining unit, Ozark aquifer, Ozark confining unit, Springfield Plateau aquifer, and Western Interior Plains confining system. Generally, the lower portion of the Ozark aquifer is the primary source of groundwater across much of Missouri and the Springfield Plateau aquifer is used across northern Arkansas. A full description of the methods used to model groundwater withdrawal rates from the Ozark system are available in Knierim et al. (2017) (see larger work citation). Briefly, groundwater use was modeled by 1) acquiring site-specific and county-level groundwater withdrawal rates and well locations (with and without pumping information) from state agencies and the U.S. Geological Survey, 2) linearly interpolating groundwater withdrawal rates to create a yearly time-step for the period of observations (generally 1962 to 2010), 3) extrapolating county-level groundwater withdrawal rates to 1900 for domestic groundwater use assuming use was linearly related to population change, then constraining groundwater withdrawal rate to 0 million liters per day (ML/d) in 1900 using a multiplier that incrementally ranged from zero in 1900 to one in 2010, 4) attributing groundwater withdrawal rates to well locations using a hierarchical process where county-level groundwater withdrawal rates were disaggregated to wells where pumping was known to occur at any time, followed by county-level groundwater withdrawal rates disaggregated to well locations with a potential groundwater-use type based on land use, and 5) aggregation into model cells (row, column, layer) and county by summing modeled site-specific groundwater withdrawal rates using well location and depth. The large dataset (148,836 well locations) and long period (110 years) necessitated modeling groundwater use programmatically using Python 2.7.

Groundwater is an often overlooked freshwater resource compared to surface water, but groundwater is used widely across the United States, especially during periods of drought. If groundwater models can successfully simulate past conditions, they may be used to evaluate potential future pumping scenarios or climate conditions, thus providing a valuable planning tool for water-resource managers. Quantifying the groundwater-use component for a groundwater model is a vital but often challenging endeavor. This dataset includes groundwater withdrawal rates modeled for the Ozark Plateaus aquifer system (Ozark system) from 1900 to 2010 by county for domestic water use. Public supply, non-agriculture, livestock, and agriculture groundwater withdrawal rates are available in the complementary dataset “Public supply, non-agriculture, livestock, and agriculture groundwater withdrawal rates from the Ozark Plateaus aquifer system, 1900 to 2010”. The Ozark system is located in the central United States and is composed of interbedded Cambrian to Pennsylvanian clastic and carbonate lithologies. In stratigraphic order, the Ozark system includes the Basement confining unit, St. Francois aquifer, St. Francois confining unit, Ozark aquifer, Ozark confining unit, Springfield Plateau aquifer, and Western Interior Plains confining system. Generally, the lower portion of the Ozark aquifer is the primary source of groundwater across much of Missouri and the Springfield Plateau aquifer is used across northern Arkansas. A full description of the methods used to model groundwater withdrawal rates from the Ozark system are available in Knierim et al. (2017) (see larger work citation). Briefly, groundwater use was modeled by 1) acquiring site-specific and county-level groundwater withdrawal rates and well locations (with and without pumping information) from state agencies and the U.S. Geological Survey, 2) linearly interpolating groundwater withdrawal rates to create a yearly time-step for the period of observations (generally 1962 to 2010), 3) extrapolating county-level groundwater withdrawal rates to 1900 for domestic groundwater use assuming use was linearly related to population change, then constraining groundwater withdrawal rate to 0 million liters per day (ML/d) in 1900 using a multiplier that incrementally ranged from zero in 1900 to one in 2010, 4) attributing groundwater withdrawal rates to well locations using a hierarchical process where county-level groundwater withdrawal rates were disaggregated to wells where pumping was known to occur at any time, followed by county-level groundwater withdrawal rates disaggregated to well locations with a potential groundwater-use type based on land use, and 5) aggregation into model cells (row, column, layer) and county by summing modeled site-specific groundwater withdrawal rates using well location and depth. The large dataset (148,836 well locations) and long period (110 years) necessitated modeling groundwater use programmatically using Python 2.7.