This data release provides a monthly irrigation water use reanalysis for the period 2000-20 for all U.S. Geological Survey (USGS) Watershed Boundary Dataset of Subwatersheds (Hydrologic Unit Code 12 [HUC12]) in the conterminous United States (CONUS). Results include reference evapotranspiration (ETo), actual evapotranspiration (ETa), irrigated areas, consumptive use, and effective precipitation for each HUC12. ETo and ETa were estimated using the operational Simplified Surface Energy Balance (SSEBop, Senay and others, 2013; Senay and others, 2020) model executed in the OpenET (Melton and others, 2021) web-based application implemented in Google Earth Engine. Results provided by OpenET/SSEBop were summarized to hydrologic response units (HRUs) in the National Hydrologic Model (NHM; Regan and others, 2019) to estimate consumptive use and effective precipitation on irrigated lands. Irrigated lands for the CONUS were provided by the Landsat-based Irrigation Dataset (LANID; Xie and others, 2019) for each year of the reanalysis period. Consumptive use estimates provided by the NHM were disaggregated to HUC12s using area weighted intersections with HRUs and the relative proportion of irrigated lands in each intersected area. These datasets are generated during the irrigation reanalysis workflow (irrigation_reanalysis.7zip). The files actet_openet.cbh, potet_openet.cbh, and dyn_ag_frac.param are created in step one of the workflow, which involves converting daily OpenET/SSEBop results into inputs for the NHM. All other files are produced by the NHM and are utilized for calculating irrigation consumptive use and effective precipitation.

This data release provides a monthly irrigation water use reanalysis for the period 2000-20 for all U.S. Geological Survey (USGS) Watershed Boundary Dataset of Subwatersheds (Hydrologic Unit Code 12 [HUC12]) in the conterminous United States (CONUS). Results include reference evapotranspiration (ETo), actual evapotranspiration (ETa), irrigated areas, consumptive use, and effective precipitation for each HUC12. ETo and ETa were estimated using the operational Simplified Surface Energy Balance (SSEBop, Senay and others, 2013; Senay and others, 2020) model executed in the OpenET (Melton and others, 2021) web-based application implemented in Google Earth Engine. Results provided by OpenET/SSEBop were summarized to hydrologic response units (HRUs) in the National Hydrologic Model (NHM; Regan and others, 2019) to estimate consumptive use and effective precipitation on irrigated lands. Irrigated lands for the CONUS were provided by the Landsat-based Irrigation Dataset (LANID; Xie and others, 2019) for each year of the reanalysis period. Consumptive use estimates provided by the NHM were disaggregated to HUC12s using area weighted intersections with HRUs and the relative proportion of irrigated lands in each intersected area. These datasets are generated during the irrigation reanalysis workflow (irrigation_reanalysis.7zip). The files actet_openet.cbh, potet_openet.cbh, and dyn_ag_frac.param are created in step one of the workflow, which involves converting daily OpenET/SSEBop results into inputs for the NHM. All other files are produced by the NHM and are utilized for calculating irrigation consumptive use and effective precipitation.

This data release provides a monthly irrigation water use reanalysis for the period 2000-20 for all USGS Watershed Boundary Dataset of Subwatersheds (Hydrologic Unit Code 12 [HUC12]) in the conterminous United States (CONUS). Results include reference evapotranspiration (ETo), actual evapotranspiration (ETa), irrigated areas, consumptive use, and effective precipitation for each HUC12. ETo and ETa were estimated using the operational Simplified Surface Energy Balance (SSEBop, Senay and others, 2013; Senay and others, 2020) model executed in the OpenET (Melton and others, 2021) web-based application implemented in Google Earth Engine. Results provided by OpenET/SSEBop were summarized to hydrologic response units (HRUs) in the National Hydrologic Model (NHM; Regan and others, 2019) to estimate consumptive use and effective precipitation on irrigated lands. Irrigated lands for the CONUS were provided by the Landsat-based Irrigation Dataset (LANID; Xie and others, 2019) for each year of the reanalysis period. Consumptive use estimates provided by the NHM were disaggregated to HUC12s using area weighted intersections with HRUs and the relative proportion of irrigated lands in each intersected area. This data release includes data and source code required to develop the irrigation reanalysis workflow along with the scripts and data required to replicate the output results. The workflow has three main steps that were automated using python scripts: 1) convert daily OpenET/SSEBop results into input for the NHM, 2) run a modified version of the NHM that is an application of the GSFLOW software package (GSFLOW version 2.3) to estimate daily results, and 3) post-process NHM results to monthly, then summarize and disaggregate ETo, ETa, irrigated areas, consumptive use, and effective precipitation to all HUC12s in the CONUS for the period 2000-20.

This data release provides a monthly irrigation water use reanalysis for the period 2000-20 for all USGS Watershed Boundary Dataset of Subwatersheds (Hydrologic Unit Code 12 [HUC12]) in the conterminous United States (CONUS). Results include reference evapotranspiration (ETo), actual evapotranspiration (ETa), irrigated areas, consumptive use, and effective precipitation for each HUC12. ETo and ETa were estimated using the operational Simplified Surface Energy Balance (SSEBop, Senay and others, 2013; Senay and others, 2020) model executed in the OpenET (Melton and others, 2021) web-based application implemented in Google Earth Engine. Results provided by OpenET/SSEBop were summarized to hydrologic response units (HRUs) in the National Hydrologic Model (NHM; Regan and others, 2019) to estimate consumptive use and effective precipitation on irrigated lands. Irrigated lands for the CONUS were provided by the Landsat-based Irrigation Dataset (LANID; Xie and others, 2019) for each year of the reanalysis period. Consumptive use estimates provided by the NHM were disaggregated to HUC12s using area weighted intersections with HRUs and the relative proportion of irrigated lands in each intersected area. This data release includes data and source code required to develop the irrigation reanalysis workflow along with the scripts and data required to replicate the output results. The workflow has three main steps that were automated using python scripts: 1) convert daily OpenET/SSEBop results into input for the NHM, 2) run a modified version of the NHM that is an application of the GSFLOW software package (GSFLOW version 2.3) to estimate daily results, and 3) post-process NHM results to monthly, then summarize and disaggregate ETo, ETa, irrigated areas, consumptive use, and effective precipitation to all HUC12s in the CONUS for the period 2000-20.

Actual evapotranspiration (ETa) values estimated for specified areas including 1) total county areas; 2) potentially irrigated areas within each county; and 3) mapped extents of irrigated lands within each county provided by some states. These ETa estimates were provided to the USGS National Water Use Science Project by the USGS Earth Resources Observation and Science (EROS) Center (Gabriel Senay and MacKenzie Friedrichs, written communication, 2/20/2017) and are based on 1-square kilometer resolution 2015 Moderate Resolution Imaging Spectroradiometer (MODIS) satellite data analyzed through the operational Simplified Surface Energy Balance (SSEBop) model using methods of Senay and others (2013). Reference: Senay, G.B., Bohms, S., Singh, R.K., Gowda, P.H., Velpuri, N.M., Alemu, H., and Verdin, J.P., 2013, Operational evapotranspiration mapping using remote sensing and weather datasets: A new parameterization for the SSEB approach; Journal of the American Water Resources Association, 49 (2013), pp. 577–591.

Actual evapotranspiration (ETa) values estimated for specified areas including 1) total county areas; 2) potentially irrigated areas within each county; and 3) mapped extents of irrigated lands within each county provided by some states. These ETa estimates were provided to the USGS National Water Use Science Project by the USGS Earth Resources Observation and Science (EROS) Center (Gabriel Senay and MacKenzie Friedrichs, written communication, 2/20/2017) and are based on 1-square kilometer resolution 2015 Moderate Resolution Imaging Spectroradiometer (MODIS) satellite data analyzed through the operational Simplified Surface Energy Balance (SSEBop) model using methods of Senay and others (2013). Reference: Senay, G.B., Bohms, S., Singh, R.K., Gowda, P.H., Velpuri, N.M., Alemu, H., and Verdin, J.P., 2013, Operational evapotranspiration mapping using remote sensing and weather datasets: A new parameterization for the SSEB approach; Journal of the American Water Resources Association, 49 (2013), pp. 577–591.

The USGS has published United States water-use data every five years since 1950. To increase the temporal and spatial availability of water use estimates using nationally consistent methods, the USGS is developing national water-use models for each major water-use category. This data release publishes crop irrigation withdrawals for the conterminous United States (CONUS) that are calculated using modeled irrigation consumptive use (Martin and others, 2023), irrigation efficiencies, and source-water proportions (Dieter and others, 2018). Crop irrigation withdrawals and irrigation consumptive use refer to water removed and consumed, respectively, from a groundwater or surface-water source to produce agricultural crops. Monthly withdrawals provided include groundwater, surface water, and the combined total withdrawal for areas contained in the twelve-digit watershed boundary (HUC12) dataset during the reanalysis period, 2000-2020. HUC12 annual 2000-2020 irrigation efficiencies included in this data release combine efficiencies from irrigation system types (accounting for water lost during application to crops) and conveyances (accounting for water lost during transmission through canals and pipes). Irrigated crops were mapped using the Landsat-based Irrigation Dataset (LANID; Xie and Lark, 2021; Martin and others, 2023) and the Cropland Data Layer (USDA NASS, 2022) that were linked to irrigation system types (USDA NASS, 2014) to estimate irrigation system efficiencies for each HUC12 in the CONUS (Howell, 2003 and FAO, 1989). Conveyance loss volumes (USDA NASS, 2020) were used to estimate and map surface-water conveyance efficiencies. Total efficiencies were calculated for HUC12 units by combining irrigation system and conveyance efficiencies. Irrigation withdrawals and efficiencies were produced using published data sources to provide these estimates in a timely manner. On-going work to develop dynamic maps of irrigation system type and other datasets for the CONUS will be used in the future to refine the estimates provided here. Estimation of irrigation withdrawals using irrigation consumptive use and efficiencies neglects some components of water use for crops, including water used for frost protection, salt leaching, harvesting, and other non-consumptive-use based treatments. For this reason, irrigation withdrawals provided here may under-estimate total withdrawals where non-consumptive treatments are significant.

The USGS has published United States water-use data every five years since 1950. To increase the temporal and spatial availability of water use estimates using nationally consistent methods, the USGS is developing national water-use models for each major water-use category. This data release publishes crop irrigation withdrawals for the conterminous United States (CONUS) that are calculated using modeled irrigation consumptive use (Martin and others, 2023), irrigation efficiencies, and source-water proportions (Dieter and others, 2018). Crop irrigation withdrawals and irrigation consumptive use refer to water removed and consumed, respectively, from a groundwater or surface-water source to produce agricultural crops. Monthly withdrawals provided include groundwater, surface water, and the combined total withdrawal for areas contained in the twelve-digit watershed boundary (HUC12) dataset during the reanalysis period, 2000-2020. HUC12 annual 2000-2020 irrigation efficiencies included in this data release combine efficiencies from irrigation system types (accounting for water lost during application to crops) and conveyances (accounting for water lost during transmission through canals and pipes). Irrigated crops were mapped using the Landsat-based Irrigation Dataset (LANID; Xie and Lark, 2021; Martin and others, 2023) and the Cropland Data Layer (USDA NASS, 2022) that were linked to irrigation system types (USDA NASS, 2014) to estimate irrigation system efficiencies for each HUC12 in the CONUS (Howell, 2003 and FAO, 1989). Conveyance loss volumes (USDA NASS, 2020) were used to estimate and map surface-water conveyance efficiencies. Total efficiencies were calculated for HUC12 units by combining irrigation system and conveyance efficiencies. Irrigation withdrawals and efficiencies were produced using published data sources to provide these estimates in a timely manner. On-going work to develop dynamic maps of irrigation system type and other datasets for the CONUS will be used in the future to refine the estimates provided here. Estimation of irrigation withdrawals using irrigation consumptive use and efficiencies neglects some components of water use for crops, including water used for frost protection, salt leaching, harvesting, and other non-consumptive-use based treatments. For this reason, irrigation withdrawals provided here may under-estimate total withdrawals where non-consumptive treatments are significant.

This data release contains the output of the Irrigation Water Use Estimation Disaggregation and Downscaling Model (IWUEDD) along with the scripts and data resources required to replicate the output results. The IWUEDD is used to estimate monthly irrigation withdrawals and consumptive use for each 12-digit hydrologic unit code (HUC 12) subwatershed in the conterminous United States. The HUC 12-level estimates are separated into groundwater (GW), surface water (SW), groundwater and surface water combined (TW), and consumptive use (CU). The IWUEDD developed monthly estimates by disaggregating and downscaling previously published annual county-level irrigation withdrawal and consumptive use data complied as part of the National Water Use Science Project, National Water Census as presented in U.S. Geological Survey data release, “Estimated use of water in the United States county-level data for 2015” (Dieter and others, 2018).

This data release contains the output of the Irrigation Water Use Estimation Disaggregation and Downscaling Model (IWUEDD) along with the scripts and data resources required to replicate the output results. The IWUEDD is used to estimate monthly irrigation withdrawals and consumptive use for each 12-digit hydrologic unit code (HUC 12) subwatershed in the conterminous United States. The HUC 12-level estimates are separated into groundwater (GW), surface water (SW), groundwater and surface water combined (TW), and consumptive use (CU). The IWUEDD developed monthly estimates by disaggregating and downscaling previously published annual county-level irrigation withdrawal and consumptive use data complied as part of the National Water Use Science Project, National Water Census as presented in U.S. Geological Survey data release, “Estimated use of water in the United States county-level data for 2015” (Dieter and others, 2018).