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.

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.

Groundwater and estuary water levels near Mill Creek, and the Herring River in Wellfleet Massachusetts were measured from June 2017 to June 14, 2018. Water-level data have been filtered to remove the effects of the daily tides. The mean daily value of the tidally filtered 15 minute water-level data is presented. The data also include a composite data set of daily precipitation values, as well as data on the growing degrees days (50 degrees Fahrenheit), from two weather stations on Cape Cod, Massachusetts.

Groundwater and estuary water levels near Mill Creek, and the Herring River in Wellfleet Massachusetts were measured from June 2017 to June 14, 2018. Water-level data have been filtered to remove the effects of the daily tides. The mean daily value of the tidally filtered 15 minute water-level data is presented. The data also include a composite data set of daily precipitation values, as well as data on the growing degrees days (50 degrees Fahrenheit), from two weather stations on Cape Cod, Massachusetts.

This data release presents water-quality and streamflow data from 12 streams on Cape Cod, Massachusetts, which were used to identify potential land areas that are sources of high nitrogen loading from groundwater directly to streams. The sources of nitrogen loading to groundwater in this region include wastewater from septic systems and fertilizer and stormwater runoff. Streamflow in the area is highly influenced by groundwater and not by direct outflows of treated wastewater. This dataset contains stream site information (CapeCodStreams_SiteInfo.csv), field and laboratory observations (CapeCodStreams_Field_Lab_QW.csv), and information on streamflow and calculated nitrogen loads (CapeCodStreams_Flow_and_Loads.csv). Additionally, the dataset provides information on simulated groundwater recharge areas contributing to individual stream reaches. Recharge area characteristics, including size, recharge quantity, groundwater travel time, nitrogen-yield characteristics, and land-use classifications, are provided (CapeCodStreams_RA_Char.csv and CapeCodStreams_RA_Wshed_Load.csv). A data dictionary (CapeCodStreams_Data_Dictionary.csv) is provided to describe column attributes and define attribute units.

This data release supports analyses of the relations between monthly average nutrient concentrations in the Herring River on the ebb tide near Wellfleet Massachusetts and monthly average precipitation, temperature, runoff, solar radiation, ocean water temperature, mean sea level, nutrient concentrations in Wellfleet Harbor, and atmospheric deposition of nitrogen 2015-2021. The Environmental_Variables.csv file contains the monthly average precipitation, temperature, runoff, solar radiation, ocean water temperature, mean sea level, nutrient concentrations in Wellfleet Harbor, and atmospheric deposition of nitrogen data. The Velocity_andgage_height.csv file contains the data on surface water velocity that were used to determine the time of the beginning of flood and ebb tides from June 2020 through December 2021. The gage height data were used as a backup to the velocity data for determining the time of the beginning of flood and ebb tides.

This data release supports analyses of the relations between monthly average nutrient concentrations in the Herring River on the ebb tide near Wellfleet Massachusetts and monthly average precipitation, temperature, runoff, solar radiation, ocean water temperature, mean sea level, nutrient concentrations in Wellfleet Harbor, and atmospheric deposition of nitrogen 2015-2021. The Environmental_Variables.csv file contains the monthly average precipitation, temperature, runoff, solar radiation, ocean water temperature, mean sea level, nutrient concentrations in Wellfleet Harbor, and atmospheric deposition of nitrogen data. The Velocity_andgage_height.csv file contains the data on surface water velocity that were used to determine the time of the beginning of flood and ebb tides from June 2020 through December 2021. The gage height data were used as a backup to the velocity data for determining the time of the beginning of flood and ebb tides.

The dataset includes information to make Figures 1 through 6 of the manuscript. This dataset is associated with the following publication: Rajib, A., H. Golden, C. Lane, and Q. Wu. Surface Depression and Wetland Water Storage Improves Major River Basin Hydrologic Predictions. WATER RESOURCES RESEARCH. American Geophysical Union, Washington, DC, USA, 56(7): e2019WR026561, (2020).

The Chesapeake Bay watershed is home to over 18.5 million people and continues to experience rapid population growth. With changes in population and land development, understanding current conditions of streams within the watershed (status), and changes in condition over time (trends) is important for assessing stream health. This data release contains the output files for results of status and trend analysis for stream water temperature, salinity, flow, hydromorphology, and biological aquatic community indicators of stream condition in the Chesapeake Bay watershed from the associated Scientific Investigative Report (https://doi.org/10.3133/sir20255072). Data and results for nutrients and suspended sediment (https://doi.org/10.5066/P97IFYES) and toxic contaminants (https://doi.org/10.5066/P9R78SQ6) were released previously.

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.