This dataset is part of the National Water Census Water Budget Estimation and Evaluation Project's ongoing development of best estimates of daily historical water budgets for over 100,000 hydrologic units across the United States. In this release, estimates of actual evapotranspiration and snowpack water equivalent storage are added to the already released estimates of soil moisture, recharge, streamflow, and precipitation. All these estimates are made available per twelve-digit hydrologic unit code watershed as contained in the NHDPlus v2.1 dataset. As this project progresses, it is expected that a complete closed water budget generated from the same water budget model will succeed this data release. For background on source data and generation of these water budget variables, see nhru_pkwater_equiv.csv and nhru_hru_actet.csv from: Hay, L.E., 2019, Application of the National Hydrologic Model Infrastructure with the Precipitation-Runoff Modeling System (NHM-PRMS), by HRU Calibrated Version: U.S. Geological Survey data release, https://doi.org/10.5066/P9NM8K8W The water budget variables were converted to a HUC12 basis using area-weighted spatial interpolation. All code used for conversions are included as an attachment to this data release. Summary of files included: 1) hu12_ids.csv - twelve digit hydrologic unit (HUC12) code identifiers used in all files 2) timesteps.csv - timesteps used in all files. 3) nhm_eta.nc - NetCDF version of actual evapotranspiration data 4) nhm_eta_grid.csv - One timestep per row version of actual evapotranspiration data 5) nhm_eta_timeseries.csv - One HUC12 per row version of actual evapotranspiration data 6) nhm_snowpack.nc - NetCDF version of snowpack water equivalent data 7) nhm_snowpack_grid.csv - One timestep per row version of snowpack water equivalent data 8) nhm_snowpack_timeseries.csv - One HUC12 per row version of snowpack water equivalent data 9) scripts.zip - A reproducible R workflow to create outputs implemented with the drake package This data release compliments the following related data releases. Soil moisture and recharge: Blodgett, D.L., 2019, Twelve digit hydrologic unit soil moisture and recharge from the National Hydrologic Model Infrastructure with the Precipitation-Runoff Modeling System: U.S. Geological Survey data release, https://doi.org/10.5066/P9ZZAWK4. Streamflow: Russell, A.M., Over, T.M., and Farmer, W.H., 2018, Statistical daily streamflow estimates at HUC12 outlets in the conterminous United States, Water Years 1981-2017: U.S. Geological Survey data release, https://doi.org/10.5066/P9DPSY6G. Precipitation: https://www.sciencebase.gov/catalog/item/52a7bed0e4b0de1a6d2dd0fd

This dataset is part of the National Water Census Water Budget Estimation and Evaluation Project's ongoing development of best estimates of daily historical water budgets for over 100,000 hydrologic units across the United States. In this release, estimates of actual evapotranspiration and snowpack water equivalent storage are added to the already released estimates of soil moisture, recharge, streamflow, and precipitation. All these estimates are made available per twelve-digit hydrologic unit code watershed as contained in the NHDPlus v2.1 dataset. As this project progresses, it is expected that a complete closed water budget generated from the same water budget model will succeed this data release. For background on generation of these water budget variables, see: Hay, L.E., 2019, Application of the National Hydrologic Model Infrastructure with the Precipitation-Runoff Modeling System (NHM-PRMS), by HRU Calibrated Version: U.S. Geological Survey data release, https://doi.org/10.5066/P9NM8K8W The water budget variables were converted to a HUC12 basis using area-weighted spatial interpolation. All code used for conversions are included as an attachment to this data release. Summary of files included: 1) huc12_ids.csv - twelve digit hydrologic unit (HUC12) code identifiers used in all files 2) timesteps.csv - timesteps used in all files. 3) nhm_eta.nc4 - NetCDF version of actual evapotranspiration data 4) nhm_eta_grid.zip - Zipped CSV with one timestep per row version of actual evapotranspiration data 5) nhm_eta_timeseries.zip - Zipped CSV with one HUC12 per row version of actual evapotranspiration data 6) nhm_snowpack.nc4 - NetCDF version of snowpack water equivalent data 7) nhm_snowpack_grid.zip - Zipped CSV with one timestep per row version of snowpack water equivalent data 8) nhm_snowpack_timeseries.zip - Zipped CSV with one HUC12 per row version of snowpack water equivalent data 9) nhm_recharge.nc4 - NetCDF version of recharge data 10) nhm_recharge_grid.zip - Zipped CSV with one timestep per row version of recharge data 11) nhm_recharge_timeseries.zip - Zipped CSV with one HUC12 per row version of recharge data 12) nhm_soil_moist.nc4 - NetCDF version of soil moisture data 13) nhm_soil_moisture_grid.zip - Zipped CSV with one timestep per row version of soil moisture data 14) nhm_soil_moisture_timeseries.zip - Zipped CSV with one HUC12 per row version of soil moisture data 15) scripts.zip - A reproducible R workflow to create outputs implemented with the drake package

This dataset is part of the National Water Census ongoing development of best estimates of daily historical water budgets for over 100,000 hydrologic units across the United States. In this release, estimates of total flow and snowmelt for each hydrologic unit are added to the already released estimates of actual evapotranspiration, snowpack water-equivalent storage, soil moisture, recharge, streamflow, and precipitation. All these estimates are made available per twelve-digit hydrologic unit code watershed as contained in the NHDPlus v2.1 dataset and associated Watershed Boundary Dataset (WBD) snapshot. As this project progresses, it is expected that a complete closed water budget generated from the same water budget model will succeed this data release. Users are advised to ignore the first two years of the simulations to account for model initialization.

For background on source data and generation of these water budget variables, see nhru_hru_outflow.csv and nhru_snowmelt.csv from:

Hay, L.E. and LaFontaine, J.H., 2020, Application of the National Hydrologic Model Infrastructure with the Precipitation-Runoff Modeling System (NHM-PRMS), 1980-2016, Daymet Version 3 calibration: U.S. Geological Survey data release, https://doi.org/10.5066/P9PGZE0S

The water budget variables were converted to a HUC12 basis using area-weighted spatial interpolation. The HUC12 version is the one included with WBD snapshot associated withe NHDPlus v2.1. All code used for conversions are published by Blodgett (2020) referenced below.

Summary of files included:
1) hu12_ids.csv.zip - twelve digit hydrologic unit (HUC12) code identifiers used in all files.
2) timesteps.csv.zip - timesteps used in all files.
3) nhm_total_flow_timeseries.csv.zip - One HUC12 per row, one date per column, version of total flow data.
4) nhm_snowmelt_timeseries.csv.zip - One HUC12 per row, one date per column, version of snowmelt data.

This data release compliments the following related data releases:

Actual evapotranspiration and snowpack water equivalent storage:
Blodgett, D.L., 2020, Twelve-digit hydrologic unit actual evapotranspiration and snowpack water equivalent storage from the National Hydrologic Model Infrastructure with the Precipitation-Runoff Modeling System 1980-2016: U.S. Geological Survey data release, https://doi.org/10.5066/P9IH7CB8.

Soil moisture and recharge:
Blodgett, D.L., 2019, Twelve digit hydrologic unit soil moisture and recharge from the National Hydrologic Model Infrastructure with the Precipitation-Runoff Modeling System: U.S. Geological Survey data release, https://doi.org/10.5066/P9ZZAWK4.

Streamflow:
Russell, A.M., Over, T.M., and Farmer, W.H., 2018, Statistical daily streamflow estimates at HUC12 outlets in the conterminous United States, Water Years 1981-2017: U.S. Geological Survey data release, https://doi.org/10.5066/P9DPSY6G.

Precipitation:
https://www.sciencebase.gov/catalog/item/52a7bed0e4b0de1a6d2dd0fd
Thornton, P.E., Thornton, M.M., Mayer, B.W., Wei, Y., Devarakonda, R., Vose, R.S., and Cook, R.B., 2017, Daymet—Daily surface weather data on a 1-km grid for North America, Version 3: ORNL DAAC website, accessed March 8, 2017, at https://doi.org/10.3334/ORNLDAAC/1328.

This dataset is part of the National Water Census Water Budget Estimation and Evaluation Project's ongoing development of best estimates of daily historical water budgets for about 100,000 hydrologic units across the United States. In this release, estimates of soil moisture and recharge are added to the already released estimates of streamflow and precipitation. All these estimates are made available per twelve-digit hydrologic unit code watershed as contained in the NHDPlusV2 dataset. As this project progresses, it is expected that a complete closed water budget generated from the same water budget model will succeed this data release. For background on generation of these wate rbudget variables, see: Hay, L.E., 2019, Application of the National Hydrologic Model Infrastructure with the Precipitation-Runoff Modeling System (NHM-PRMS), by HRU Calibrated Version: U.S. Geological Survey data release, https://doi.org/10.5066/P9NM8K8W The water budget variables were converted to a hydrologic unit basis using area-weighted spatial interpolation. All code used for conversions are included as an attachment to this data release. Summary of Files Included: 1) hu12_ids.csv - twelve digit hydrologic unit code identifiers used in all files. 2) timesteps.csv - timesteps used in all files. 3) nhm_recharge.nc - NetCDF version of recharge data 4) nhm_recharge_grid.csv - One timestep per row version of recharge data 5) nhm_recharge_timeseries.csv - One HUC12 per row version of recharge data 6) nhm_soil_moist.nc - NetCDF version of soil moisture data 7) nhm_soil_moisture_grid.csv - One timestep per row version of soil moisture data 8) nhm_soil_moisture_timeseries.csv - One HUC12 per row version of soil moisture data 9) scripts.zip - A reproducible R workflow to create outputs implemented with the drake package.

This data release contains three variables from the National Hydrologic Model Infrastructure with the Precipitation-Runoff Modeling System (NHM-PRMS) version 1.1 modeling application forced with CONUS404-BA (Markstrom and others, 2024) from January 1st, 1980 through September 25th, 2021 that are summarized to a twelve-digit hydrologic unit code for the spatial extent of the conterminous United States at a daily timestep. The three variables presented here are snow water equivalent, actual evapotranspiration, and soil moisture fraction. There are three netCDF files of daily, modeled data; one for each of the following variables: actual evapotranspiration - "huc12_daily_nhmprms-conus404ba_actet.nc", soil moisture fraction - "huc12_daily_nhmprms-conus404ba_soil_moisture_fraction.nc", and snow water equivalent - "huc12_daily_nhmprms-conus404ba_pkwater_equiv.nc". Additionally, two supplementary files are also included in this data release. The first file (“weights_hru_to_huc12_nhmprms_conus404ba.csv”) contains the spatial weights or fraction that is used to “weight” the modeling output in the area-weighting process. The second file (“summed_weights_per_huc12_nhmprms_conus404ba.csv”) contains the total fractional area within each twelve-digit hydrologic unit code that is covered by the modeling output and is important for filtering results in the data file (where a fractional coverage may be less than one).

This data release contains inputs and outputs for hydrologic simulations of the conterminous United States (CONUS) using the National Hydrologic Model (NHM) application of the Precipitation Runoff Modeling System (PRMS) in ASCII and binary format and explanatory graphics in pdf format. These simulations were developed to provide estimates of water availability for historical conditions for the period October 1, 1980 to September 30, 2016 for five different calibration configurations; the first three years of the simulation should be considered the initialization period and should not be used for subsequent analysis. The five versions of model parameters and associated model output included in this data release are described in table 1 and in the Supplemental Information section of this metadata record. Table 2 provides information about the baseline datasets used for model calibration for each of the five parameter configurations. Figure 1 shows a schematic of the multi-step calibration procedure used to develop the model parameters. Table 3 describes the 36 model output variables that are included in the five attached folders. Five .tar folders are named according to the simulation configuration in table 1 and include the 36-model output variable files. Table 4 provides information about the 8,274 streamgage locations that are included in the NHM-PRMS. The NHM-PRMS parameter and control files for each of the five simulations are located on the child pages associated with this data release. The PRMS climate forcing input files for the simulations are in the DAYMET_CBH.zip folder. Summary files by streamgage of measured and simulated streamflow for the byHRU, byHRU_musk, and byHRU_musk_obs simulations are in the Streamgage_location_simulations_5999.zip folder. Any time series data in the model output files prior to the October 1, 1983 start date should be considered part of the model initialization period and should not be used. Please refer to the Supplemental Information element of this metadata record for more information about the model calibration, inputs, outputs, and summaries included in this data release.

This data release contains inputs for and outputs from hydrologic simulations for the conterminous United States (CONUS) using the Precipitation Runoff Modeling System (PRMS) version 5.1.0 and the USGS National Hydrologic Model infrastructure (NHM, Regan and others, 2018). These simulations were developed to provide estimates of the water budget for the period 1950 to 2010. Specific file types include: 1) input atmospheric forcings of minimum air temperature, maximum air temperature, and daily precipitation accumulation derived from a gridded observation-based dataset developed by Maurer and others (2002), 2) input parameter files for static and dynamic land cover conditions, and 3) output files of simulated water budget components for each hydrologic response unit and stream segment. Figure 1 shows the calibration methodology that was used for the model application (see LaFontaine and others, 2019 for additional information). Table 1 lists the streamgages that are included in the model application. Table 2 lists the calibration datasets that were used in addition to USGS measured streamflow. The first three years of the simulations are considered 'model initialization' and should not be included in any subsequent analsysis.

This data release contains inputs for and outputs from hydrologic simulations for the conterminous United States (CONUS) using the Precipitation Runoff Modeling System (PRMS) version 5.1.0 and the USGS National Hydrologic Model infrastructure (NHM, Regan and others, 2018). These simulations were developed to provide estimates of the water budget for the period 1950 to 2010. Specific file types include: 1) input atmospheric forcings of minimum air temperature, maximum air temperature, and daily precipitation accumulation derived from a gridded observation-based dataset developed by Maurer and others (2002), 2) input parameter files for static and dynamic land cover conditions, and 3) output files of simulated water budget components for each hydrologic response unit and stream segment. Figure 1 shows the calibration methodology that was used for the model application (see LaFontaine and others, 2019 for additional information). Table 1 lists the streamgages that are included in the model application. Table 2 lists the calibration datasets that were used in addition to USGS measured streamflow. The first three years of the simulations are considered 'model initialization' and should not be included in any subsequent analsysis.

This data release contains inputs for and outputs from hydrologic simulations for the conterminous United States (CONUS) using the Precipitation Runoff Modeling System (PRMS) version 5.2.1 and the USGS National Hydrologic Model infrastructure (NHM, Regan and others, 2018). These simulations were developed to provide estimates of the water budget for the period 1979 to 2021 for one pre-calibration and three calibration configurations: 1) calibration by hydrologic response unit (byHRU), 2) calibration by select headwaters (byHW), and 3) calibration by select headwaters with streamflow observations (byHWobs). The three versions of model parameters and associated model output included in this data release are described in Hay and others (2023). Specific file types include: 1) input atmospheric forcings of minimum air temperature, maximum air temperature, and daily precipitation accumulation derived from a gridded observation-based dataset developed by Abatzoglou (2013), 2) input parameter files, 3) output files of simulated water budget components for each hydrologic response unit and stream segment, and 4) performance statistics at selected streamgage locations. The first three years of the simulations are considered 'model initialization' and should not be included in any subsequent analysis.

This data release contains 16 variables from the National Hydrologic Model Infrastructure with the Precipitation-Runoff Modeling System (NHM-PRMS) modeling application forced with Daymet version 4 (Rosa and others, 2025) from 1980 through 2021 that are summarized to a monthly time step and a twelve-digit hydrologic unit code for the spatial extent of Hawaii. The following fluxes and storages are included: total monthly precipitation, evapotranspiration, lateral flow, surface runoff, quickflow, interflow, recharge, groundwater flow, and the average monthly snow water equivalent, interflow storage, groundwater storage, total storage, and soil moisture. These data can be found in the “HI_huc12_monthly_nhmprms_daymet_1980_2021.nc” file. Additionally, two supplementary files are also included in this data release. The first file (“HI_weights_hru_to_huc12_nhmprms_daymet.csv”) contains the spatial weights or fraction that is used to “weight” the modeling output in the area-weighting process. The second file (“HI_summed_weights_per_huc12_nhmprms_daymet.csv”) contains the total fractional area within each twelve-digit hydrologic unit code that is covered by the modeling output and is important for filtering results in the data file (where a fractional coverage may be less than one). In the version 2.0 data release update, a new variable was added to the “HI_huc12_monthly_nhmprms_daymet_1980_2021.nc” file. Additionally, several new netCDF files were added that contain data summarizations from a different production run (output data referenced as "byPOIobs") within the model application data release by Rosa and others (2025). Two of the three files added contain daily estimates of soil moisture fraction ("HI_byPOIobs_huc12_daily_soil_moisture_fraction_nhmprms_daymet_1980_2021.nc") and daily estimates of snow water equivalent ("HI_byPOIobs_huc12_daily_pkwater_equiv_nhmprms_daymet_1980_2021.nc") at the twelve-digit hydrologic unit code spatial regions. The third file added contains monthly estimates of 16 variables from the "byPOIobs" modeling application production run ("HI_byPOIobs_huc12_monthly_nhmprms_daymet_1980_2021.nc"). See the file, “revision_history_nhmprms_daymet_PR.txt” for a full description of the revisions.