This data release contains extended estimates of daily groundwater levels and monthly percentiles at 27 short-term monitoring wells in Massachusetts. The Maintenance of Variance Extension Type 1 (MOVE.1) regression method was used to extend short-term groundwater levels at wells with less than 10 years of continuous data. This method uses groundwater level data from a correlated long-term monitoring well (index well) to estimate the groundwater level record for the short-term monitoring well. MOVE.1 regressions are used widely throughout the hydrologic community to extend flow records from streamgaging stations but are less commonly used to extend groundwater records at wells. The data in this data release document the results of the MOVE.1 regressions to estimate groundwater levels and compute updated monthly percentiles for select wells used in the groundwater index in the Massachusetts Drought Management Plan (2019). The U.S. Geological Survey (USGS) groundwater identification site numbers and groundwater level data are available via the USGS National Water Information System (NWIS) database (available at https://waterdata.usgs.gov/nwis). Groundwater levels provided are in depth to water level, in feet below land surface datum. This data release accompanies a USGS scientific investigations report that describes the methods and results in detail (Ahearn and Crozier, 2024). Reference: Massachusetts Executive Office of Energy and Environmental Affairs and Massachusetts Emergency Management Agency, 2019, Massachusetts drought management plan: Executive Office of Energy and Environmental Affairs, 115 p., accessed September 2022, at https://www.mass.gov/doc/massachusetts-drought-management-plan The following are included in the data release: (1) R input file that lists the final site pairings (R_Input_MOVE1_Site_List.csv) (2) R script that performs the MOVE.1 and produces outputs for evaluation purposes (MOVE1_R_code.R) (3) MOVE.1 model outputs (MOVE1_Models.zip) (4) Estimates of daily groundwater levels using the MOVE.1 regression technique (MOVE1_Estimated_Record_Tables.zip) (5) Plots showing time series of estimated daily groundwater levels from the MOVE.1 technique (MOVE1_Estimated_Record_Plots.zip) (6) Plots showing time series of estimated daily groundwater levels from the MOVE.1 technique zoomed into the period of observed daily groundwater levels for the short-term site (Zoomed_MOVE1_Estimated_Record_Plots.zip) (7) Plots showing residuals (Residuals_WL_Plots.zip) (8) Monthly percentile table for 27 study wells (GWL_Percentiles_All_Study_Wells.csv)

A method to estimate the probable high groundwater level in Massachusetts, excluding Cape Cod and the Islands was developed in 1981. The method, commonly called the “Frimpter Method,” uses a groundwater measurement from a test site, groundwater measurements from an index well, and a distribution of high groundwater levels from wells in similar geologic and topographic settings. Historic groundwater-level statistics (maximum and 90th percentile groundwater level and annual groundwater-level range) were calculated for 153 wells in Massachusetts and nearby States to update the method inputs. In addition, as part of a comparison of approaches to determine the best index well for a given site, a multiple linear regression equation was developed to explore the relations between predictor variables and the correlations, with the goal of predicting the most highly correlated index well for each test site. This data release includes the calculated groundwater level statistics, the ancillary data used in the regression model, comparison of the data among well pairs, and predictions of the correlations among all well pairs.

A dataset of well information and geospatial data was developed for 426 U.S. Geological Survey (USGS) observation wells in Connecticut, Maine, Massachusetts, New Hampshire, Rhode Island, and Vermont. An extensive list of attributes is included about each well, its location, and water-level history to provide the public and water-resources community with comprehensive information on the USGS well network in New England and data available from these sites. These data may be useful for evaluating groundwater conditions and variability across the region. The well list and site attributes, which were extracted from USGS National Water Information System (NWIS), represent all of the active wells in the New England network up to the end of 2017, and an additional 45 wells that were inactive (discontinued or replaced by a nearby well) at that time. Inactive wells were included in the database because they (1) contain periods of water-level record that may be useful for groundwater assessments, (2) may become active again at some point, or (3) are being monitored by another agency (most discontinued New Hampshire wells are still being monitored and the data are available in the National Groundwater Monitoring Network (https://cida.usgs.gov/ngwmn/index.jsp). The wells in this database have been sites of water-level data collection (periodic levels and/or continuous levels) for an average of 31 years. Water-level records go back to 1913. The groundwater-level statistics included in the dataset represent hydrologic conditions for the period of record for inactive wells, or through the end of water year 2017 (September 30, 2017) for active wells. Geographic Information Systems (GIS) data layers were compiled from various sources and dates ranging from 2003 to 2018. These GIS data were used to calculate attributes related to topographic setting, climate, land cover, soil, and geology giving hydrologic and environmental context to each well. In total, the data include 90 attributes for each well. In addition to site number and station name, attributes were developed for site information (15 attributes); groundwater-level statistics through water year 2017 (16 attributes); well-construction information (9 attributes); topographic setting (11 attributes); climate (2 attributes); land use and cover (17 attributes); soils (4 attributes); and geology (14 attributes). Basic well and site information includes well location, period of record, well-construction details, continuous versus intermittent data collection, and ground altitudes. Attributes that may influence groundwater levels include: well depth, location of open or screened interval, aquifer type, surficial and bedrock geology, topographic position, flow distance to surface water, land use and cover near the well, soil texture and drainage, precipitation, and air temperature.

A dataset of well information and geospatial data was developed for 426 U.S. Geological Survey (USGS) observation wells in Connecticut, Maine, Massachusetts, New Hampshire, Rhode Island, and Vermont. An extensive list of attributes is included about each well, its location, and water-level history to provide the public and water-resources community with comprehensive information on the USGS well network in New England and data available from these sites. These data may be useful for evaluating groundwater conditions and variability across the region. The well list and site attributes, which were extracted from USGS National Water Information System (NWIS), represent all of the active wells in the New England network up to the end of 2017, and an additional 45 wells that were inactive (discontinued or replaced by a nearby well) at that time. Inactive wells were included in the database because they (1) contain periods of water-level record that may be useful for groundwater assessments, (2) may become active again at some point, or (3) are being monitored by another agency (most discontinued New Hampshire wells are still being monitored and the data are available in the National Groundwater Monitoring Network (https://cida.usgs.gov/ngwmn/index.jsp). The wells in this database have been sites of water-level data collection (periodic levels and/or continuous levels) for an average of 31 years. Water-level records go back to 1913. The groundwater-level statistics included in the dataset represent hydrologic conditions for the period of record for inactive wells, or through the end of water year 2017 (September 30, 2017) for active wells. Geographic Information Systems (GIS) data layers were compiled from various sources and dates ranging from 2003 to 2018. These GIS data were used to calculate attributes related to topographic setting, climate, land cover, soil, and geology giving hydrologic and environmental context to each well. In total, the data include 90 attributes for each well. In addition to site number and station name, attributes were developed for site information (15 attributes); groundwater-level statistics through water year 2017 (16 attributes); well-construction information (9 attributes); topographic setting (11 attributes); climate (2 attributes); land use and cover (17 attributes); soils (4 attributes); and geology (14 attributes). Basic well and site information includes well location, period of record, well-construction details, continuous versus intermittent data collection, and ground altitudes. Attributes that may influence groundwater levels include: well depth, location of open or screened interval, aquifer type, surficial and bedrock geology, topographic position, flow distance to surface water, land use and cover near the well, soil texture and drainage, precipitation, and air temperature.

The files and folders in this data release contain the input and output files and MATLAB algorithms used for simulations described in the associated journal article (https://doi.org/10.1007/s10040-024-02868-x). The algorithms implement a data-driven, mechanistic model of vertical infiltration through the unsaturated zone and recharge to the water table that is developed from water-balance concepts. The model of infiltration and recharge is defined in terms of observed states (such as, the water-table altitude) and unobserved states (such as, fluxes through the unsaturated zone and recharge to the water table) and includes both diffuse and preferential flow through the unsaturated zone to the water table. Estimates of the daily contributions to recharge at the water table from diffuse and preferential flow are performed by interpreting daily time-series records of observations of water-table altitude and meteorological inputs (such as, the liquid precipitation rate, snowmelt rate, and the Potential Evapotranspiration (PET) rate). The modeling approach used here is an extension of concepts of modeling infiltration and rapid recharge originally presented in Shapiro and Day-Lewis (2021) https://doi.org/10.1029/2020WR029110 and Shapiro and others (2022) (https://doi.org/10.1111/gwat.13206). The model of infiltration and recharge to the water table is applied to daily records available at 32 U.S. Geological Survey (USGS) Climate Response Network (CRN) wells located in the Delaware River Basin (DRB) in the eastern United States from January 1, 2005, through December 31, 2021. The daily water-table altitude and the meteorological records described in the associated journal article (https://doi.org/10.1007/s10040-024-02868-x) are included as input files to the MATLAB algorithms described in this data release.

Groundwater and estuary water levels near Mill Creek and the Herring River in Wellfleet, Massachusetts, were measured from June 2017 to August 2022. The data contained in these datasets consist of tables of updated statistics provided in the original work by Mullaney and others (2020, Appendix 2) and associated data release by Mullaney and Barclay (2020). The data include summary tables of water-level statistics and summary tables of updated statistical coefficients for the models in the original work. The data release also includes the underlying input data sets for these statistical regression models and an update of table 2 from the larger work, which consists of summary statistics of water levels for the period of data analysis from 2017-06-01 to 2022-08-05. Mullaney, J.R., and Barclay, J.R., 2020, Data on Tidally Filtered Groundwater and Estuary Water Levels, and Climatological Data Near Mill Creek and the Herring River, Cape Cod, Wellfleet, Massachusetts, 2017-2018: U.S. Geological Survey data release, https://doi.org/10.5066/P9T167II. Mullaney, J.R., Barclay, J.R., Laabs, K.L., and Lavallee, K.D., 2020, Hydrogeology and interactions of groundwater and surface water near Mill Creek and the Herring River, Wellfleet, Massachusetts, 2017–18: U.S. Geological Survey Scientific Investigations Report 2019–5145, 60 p., https://doi.org/10.3133/sir20195145.

The U.S. Geological Survey (USGS), in cooperation with the Massachusetts Department of Conservation and Recreation, Office of Water Resources, developed regional regression equations for estimating selected low-flow statistics in the Plymouth-Carver Kingston-Duxbury aquifer area of southeastern Massachusetts and Cape Cod. This data release child item provides streamflow statistics and basin characteristics (potential explanatory variables) for groundwater contributing areas of 4 USGS streamgages with 14 water years or more of record, 3 discontinued USGS streamgages with 1 to 3 water years of record, and 11 USGS partial-record stations with at least 10 or more miscellaneous measurements. These data were used to develop regional regression equations for the 99-, 98-, 95-, 90-, 85-, 80-, 75-, 70-, 60-, and 50-percent flow durations. Information on Maintenance of Variance Extension, type 1 (MOVE.1) record extension analyses for estimated streamflow statistics at the 3 discontinued streamgages and 11 partial-record stations are provided. The Weighted-Multiple-Linear Regression (WREG) input and output files used to develop the final regional regression equations for Massachusetts are also provided. This child item also provides additional streamflow statistics for the: 40-, 30-, 25-, 20-, 15-, 10-, 5-, 2-, and 1-percent flow durations; monthly 90- and 50-percent flow durations; monthly median of the monthly means; harmonic mean; median of the annual 7-day low flow; and the 7-day, 2-year (7Q2), 7-day, 10-year (7Q10), 30-day, 2-year (30Q2), and 30-day, 10-year (30Q10) low-flow frequencies for the 18 sites (7 streamgages and 11 partial-record stations).

This data release contains groundwater flux estimates from twelve locations in wetlands surrounding the Quashnet River in Cape Cod, located near Mashpee and Falmouth, Massachusetts. A VTP (i.e., rod with vertical temperature sensors with known spacings and depths) was also installed at a key groundwater discharge location to estimate 1D groundwater flux through time (Sohn et al., 2024). Vertical discharge flux patterns were estimated over time using the extended Kalman Filter (EKF) recursive estimation approach of McAliley et al. (2022). The EKF method was used to recursively estimate specific discharge in discrete time when temperature measurements were acquired (i.e., hourly) at each discharge location. The methodology used here has been previously tested on both synthetic and field data in McAliley et al. (2022) where EKF methods were shown to converge to step changes in synthetic discharge data on sub-daily timescales, and residuals between observed (i.e., field observations) and estimated (i.e., EKF predictions) temperatures were generally within 0.1°C, consistent with expected measurement precision. Further information on the numerical implementation, comparisons to synthetic and field observations, as well as links to open-source code can be found in McAliley et al. (2022). To complement these estimates, discrete measurements of groundwater discharge were taken using seepage meters directly coupled to the streambed interface. Vertical head gradients were also measured in some seeps and mean hydraulic conductivity values obtained from seepage meter measurements were used to produce estimates of 1D groundwater flux (m/d) from measured head differentials. This release covers data associated with the estimation of groundwater flux from these identified discharge zones using the methods above described above.

This dataset includes grid node locations at which groundwater altitudes were estimated for April 10, 1980 and April 10, 2016 using the general additive model (GAM) and groundwater observations from the USGS NWIS web interface.

This product contains time-series data for groundwater level altitudes in bedrock boreholes and meteorological information from a site administered by the U.S. Department of Agriculture (USDA), Agricultural Research Service (ARS). The site, referred to as the Masser Groundwater Recharge Site, is located in the Valley and Ridge Physiographic Province of eastern-central Pennsylvania, USA, approximately 40 kilometers (km) north of Harrisburg, Pennsylvania, USA. The period of record for the time-series data included in this product is from February 1, 1999 to December 31, 1999, which corresponds to an investigation of time-varying groundwater recharge from precipitation events. The groundwater level altitudes in bedrock boreholes and precipitation from a meteorological station at the USDA, ARS site are collected and reported at 30-minute intervals. The average, minimum, and maximum daily air temperatures at the site are acquired for the period of record from gridded data provided by the National Oceanic and Atmospheric Administration (NOAA). Time-series groundwater level altitudes for U.S. Geological Survey (USGS) well (site number: 404239076362001) is also included (U.S. Geological Survey, National Water Information System).