Geodatabase and raster datasets for the potentiometric-surface maps and depth-to-water surfaces of the Nacatoch and Tokio aquifers, 2017

This data release contains the geodatabases and raster datasets used to construct the 2017 potentiometric‑surface maps and depth-to-water surfaces for the Nacatoch and Tokio aquifers. The datasets include: (1) groundwater‑level measurements and groundwater-altitude (GWA) from wells measured in 2017; (2) surface-water-altitude (SWA) from streamgages, if available, located within outcrop regions of the aquifers and active in 2017; (3) interpreted potentiometric‑surface contours, in feet; (4) potentiometric‑surface rasters, in feet; (5) potentiometric‑surface rasters, in meters; and (6) a depth‑to‑water raster, in feet.

Potentiometric‑surface conditions are ideally represented using groundwater‑level measurements collected within a short time interval. Most groundwater‑level measurements in 2017 were collected between March 30 to August 3, 2017 (40 wells in the Nacatoch aquifer and 24 wells in the Tokio aquifer), due to scheduling and logistical constraints.  As a result, only select wells with groundwater‑level measurements collected in the shortest timeframe were used in the potentiometric‑surfaces and depth-to-water-surface for the Nacatoch and Tokio aquifers. GWA and SWA used or evaluated for inclusion in the potentiometric‑surfaces are identified in the fields USE_2017 and USECMT2017.   All GWA and SWA values are referenced to the North American Vertical Datum of 1988 (NAVD 88).
 
The resulting potentiometric-surface contours and rasters depict generalized groundwater conditions within portions of the Nacatoch and Tokio aquifers where data coverage allowed reliable interpretation, therefore these data may not be suitable for certain purposes such as groundwater-flow models or fine‑scale applications.