Huc8

Apr 22, 2017 · The Watershed Boundary Dataset (WBD) is a comprehensive aggregated collection of hydrologic unit (HU) data consistent with the national criteria for delineation and resolution. It defines the areal extent of surface water drainage to a point except in coastal or lake front areas where there could be multiple outlets as …

Unique identifier. The first eight digits are the WBD_HUC8. The next six digits are randomly assigned, sequential numbers that are unique within a HUC8. Text: True: 14 For event feature classes, this value is the ReachCode on which the event is located. ReachResolution: Source resolution. Long Integer: FalseEach dot represents all field areas in the same category (“no irrigation no tile”, irrigated or tiled) in the models (HUC8) located within the states in the Corn Belt. The entire corn or soybean producing area in a single simulation (HUC8) is considered as 100%, hence the percentage of a field category in a single HUC8 may fall within 0–100%.Crop-specific monthly HUC8-level consumptive blue water use values were disaggregated by source (surface or groundwater) and converted from consumptive use to withdrawals using 2010 county-level ...Watershed Locator. USGS The National Map: National Boundaries Dataset, 3DEP Elevation Program, Geographic Names Information System, National Hydrography Dataset, National Land Cover Database, National Structures Dataset, and National Transportation Dataset; USGS Global Ecosystems; U.S. Census Bureau TIGER/Line data; USFS Road Data; …Mississinewa. Basin. Upper. Wabash Basin. Midle Ohio-. Laughery Basin. Little. Miami Basin. Ohio Brush-. Whiteoak Basin. Little. S cioto-. Tygarts.Locate Your Watershed (Legacy 8-digit HUC) Locate Your Watershed by 12-digit HUC. Links By Watershed Information Discovery. Active Projects. Databases. Publications. Reports. Data Integration: Watersheds.This dataset shows the extent of the combined study area for the Kansas LiDAR-based playa mapping and assessment projects examined for EPA Award Number CD97743401 and EPA Award Number CD97763601, administered …For each area, we aggregated the recharge estimates and took the spatial average (in mm/yr), for each of the Hydrologic Unit Code 8 (HUC8) watersheds; we then multiplied by the area of the watershed to determine the maximum sustained yield (m3/yr) for each area. We now have groundwater availability estimates for 240 HUC8 watersheds in Alberta.

Watershed Boundaries (HUC8, HUC10, and HUC12) A watershed is the area of land draining to a stream, river, lake, or other waterbody. Watersheds are divided by high points on the land, such as ridges, mountains, and hills, and may be made up of many smaller drainage areas, or subwatersheds. Data Basin is a science-based mapping and analysis platform that supports learning, research, and sustainable environmental stewardship.Summertime Clarity Percentiles by Region. Average summertime (June–September) clarity values calculated from 2018 through 2020 clarity are compared against the values for other lakes throughout the state, as well as county, ecoregion, and watershed (HUC4 and HUC8).2.1 R packages (NonCompart and ncar) Two R packages (NonCompart and ncar) for NCA were developed in the open-source R programming language in order to allow free public use. R packages can be installed and loaded using the following scripts. Detailed documentation and examples for each package can be found on the online user manual …Watershed Boundary Dataset 01 -- New England Region 0101 -- St. John 010100 -- St. John 01010001 -- Upper St. John 6650 01010002 -- Allagash 1235 01010003 -- FishHydrologic Units (HUs) represent the area of the landscape that drains to a portion of the stream network. Each drainage has a unique Hydrologic Unit Code (HUC). The most current national HU dataset is the Watershed Boundary Dataset (WBD). HUCs from other sources might be out of date or differ from the WBD standards. The WBD includes six required levels of nested HU polygons (2- to 12-digit ...Each hydrologic unit is identified by a unique hydrologic unit code (HUC) consisting of two to eight digits based on the four levels of classification in the hydrologic unit system. [Figure 1. Map of Water Resources Regions] Click for a larger (13K) image.

We find that 87 and 64% of gauged HUC8 have biases within ±15 and ±10%, respectively, demonstrating that our hybrid workflow can well reproduce the climatology of observed WAFR pot in the historical period. However, the performance over ungauged HUC8 is hard to assess directly due to lack of streamflow observations. Alternatively, we examine the …Watershed Boundary Dataset 01 -- New England Region 0101 -- St. John 010100 -- St. John 01010001 -- Upper St. John 6650 01010002 -- Allagash 1235 01010003 -- FishThe Watershed Boundary Dataset (WBD) is a comprehensive aggregated collection of hydrologic unit (HU) data consistent with the national criteria for delineation and resolution. It defines the areal extent of surface water drainage to a point except in coastal or lake front areas where there could be multiple outlets as …Nutrient Yields Highlight Potentially Problematic Inputs from Small Tributaries. Like nutrient concentrations and loads, nutrient yields exhibited wide variation across Lake Michigan’s tributaries. TN yields ranged from …NHDPlusV1 HUC8 Dataset. You may need additional software to view some of the links on this page. See EPA’s Free Viewers and Readers page. The links will vary in file size. The following links exit the site Exit.20 Oca 2023 ... The Watershed and Subwatershed hydrologic unit boundaries provide a uniquely identified and uniform method of subdividing large drainage ...

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Title: NHD - Watershed Boundaries HUC 8. Online Linkage: https://services.wygisc.org/HostGIS/rest/services/GeoHub/NHDWatersheds8Digit/MapServer. …County-scale data were converted to HUC8-scale data by rasterizing county-scale data to 30 arcsecond resolution (∼1 km × ∼ 1 km at the equator) and summarizing by HUC8 using the Zonal Statistics tool in ArcMap 10.0. We estimated the spatial distributions of wastewater and inorganic N deposition to the US using the following methods.As shown on Figure X, this service area includes the Lower Cumberland (05130205 HUC8) and Red (05130206 HUC8) watersheds and portions of the Upper Cumberland-Lake Cumberland (05130103 HUC8), Obey (05130105 HUC8), and Rockcastle (05130102 HUC8) watersheds within the state of Kentucky.The spherical coordinate system is commonly used in physics.It assigns three numbers (known as coordinates) to every point in Euclidean space: radial distance r, polar angle θ (), and azimuthal angle φ ().The symbol ρ is often used instead of r.. In geometry, a coordinate system is a system that uses one or more numbers, or coordinates, to uniquely …

County-scale data were converted to HUC8-scale data by rasterizing county-scale data to 30 arcsecond resolution (∼1 km × ∼ 1 km at the equator) and summarizing by HUC8 using the Zonal Statistics tool in ArcMap 10.0. We estimated the spatial distributions of wastewater and inorganic N deposition to the US using the following methods.Nonpoint Source. What is a Watershed. Hydrologic Unit Codes: What Are They. The hydrologic unit code (HUC) is a numbering system for watersheds. It was developed by the U.S. Geological Survey (USGS) in cooperation with the U.S. Water Resource Council and the U.S. Department of Agriculture Natural Resources Conservation Service (NRCS) to provide ...HUC 8 maps the subbasin level, analogous to medium-sized river basins (about 2200 nationwide, pictured in red in the image); and HUC 12 is a more local sub ...4 Eyl 2020 ... Sargent, B.P., Houston, N.A., Heal, E.N., 2020, Estimated Use of Water by Subbasin (HUC8) in the Red River Basin, 2010 and 2015: U.S. Geological ...Self-supplied domestic populations, by HUC8 and county, and by water source. Studies of actual metered domestic withdrawals, monthly by source. Improve estimates of self-supplied populations by utilizing property data and/or public water supply service areas, or other methods. Irrigation - Golf CoursesIn contrast, hydrologic units are drainage areas that are delineated so as to nest into a multi-level hierarchical drainage system. Aside from the surface waters that are collected within the boundary of a hydrologic unit, it may also accept water from one or more points outside of the unit’s boundary. The tidal portion of the James River is ...Feb 16, 2019 · The Watershed Boundary Dataset is public information and may be interpreted by all organizations, agencies, units of government, or others based on needs; however, they are responsible for the appropriate application of the data. Federal, State, or local regulatory bodies are not to reassign to the Natural Resources Conservation Service any ... Apr 22, 2017 · The Watershed Boundary Dataset (WBD) is a comprehensive aggregated collection of hydrologic unit (HU) data consistent with the national criteria for delineation and resolution. It defines the areal extent of surface water drainage to a point except in coastal or lake front areas where there could be multiple outlets as … This USGS data release consists of three datasets representing three derived outlets or "pour points" for each 12-digit hydrologic unit (HU12) in the Watershed Boundary Dataset (WBD) snapshot delivered with NHDPlus V2.1.Postal_Code: 30334. Country: USA. Contact_Voice_Telephone: 404-651-8482. Contact_Facsimile_Telephone: 404-651-9590. Contact_Electronic_Mail_Address: [email protected] List of Acronyms: DNR – Georgia Department of Natural Resources DNR EPD - Georgia Department of Natural Resources, Environmental Protection Division DNR EPD GSB - Georgia ...Description. HUC 8, 10 and 12 hydrologic units in Ohio. Zooming into the map will show surface water monitoring stations (EA3), aquatic life use designations for streams and rivers, and NPDES individual permits.West Virginia has 32 watersheds divided according to hydrologic unit codes (HUC) that contribute to the Chesapeake Bay and the Gulf of Mexico. The waters west of the eastern continental divide flow into the Ohio River. The Ohio joins the Mississippi River at Cairo, IL. The Mississippi flows into the Gulf of Mexico at New Orleans, LA.

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Areal Reduction Factors (ARFs): An adjustment factor used to generate spatially averaged precipitation totals based on areal extent and point precipitation frequency data. In general, the areal reduction factor adjustment for larger watershed areas results in …WBD contains eight levels of progressive hydrologic units identified by unique 2- to 16-digit codes. The dataset is complete for the United States to the 12-digit hydrologic unit. The 8-digit level unit is often referred to as HUC8 and is a commonly used reference framework for planning and environmental assessment. Locate Your Watershed. Click on the Map Above to View a Particular Region. • Try the new Watershed Finder Menu Interface. USGS Water. Science in Your Watershed. Surf Your Watershed. Know Your Watershed. HELP! Locate Your Watershed Mapping Interface for Science in Your Watershed of the U.S. Geological Survey. Cross Creek (Cape Fear River tributary) / 35.13111°N 78.94250°W / 35.13111; -78.94250. / 35.05111°N 78.85694°W / 35.05111; -78.85694. Cross Creek is a 9.70 mi (15.61 km) long 4th order tributary to the Cape Fear River in …by Hydrologic Unit Code 8 (HUC8) Watershed Watershed Name HUC8 Code Stream Name Lehigh River Middle West Branch Susquehanna. Pennsylvania. 02050203 Bald Eagle Creek Barney Run County Line Branch Cross Fork Dyer Branch Fish Dam Run Gravel Lick Hall Run Hyner Run Hyner Run Kettle Creek Laurelly Fork Laurely Fork Left Branch Young Womans Creek ... A pdf file which lists the 2-digit, 4-digit, 6-digit and 8-digit hucs for the WBD and their naming convention is available at wbd_huc8.pdf. ( This pdf file is no longer accurate ) The Watershed Boundary Dataset (WBD) - is a nationally consistent watershed dataset that is subdivided into 6 levels (12-digit hucs) and is available from the USGS ...Hydrologic Units (HUs) represent the area of the landscape that drains to a portion of the stream network. Each drainage has a unique Hydrologic Unit Code (HUC). The most current national …

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wbd (MapServer) View In: ArcGIS JavaScript ArcGIS Online Map Viewer ArcGIS Earth ArcMap ArcGIS Pro. View Footprint In: ArcGIS Online Map Viewer. Service Description: Abstract: This file contains Hydrologic Unit (HU) polygon boundaries for the United States, Puerto Rico, and the U.S. Virgin Islands. The data is a seamless National representation ... get_huc8() Find WBD HUC 08 unit subsets (DEPRECATED) get_nhdarea() Find NHD Areas. get_waterbodies() Find NHD Water Bodies. get_nwis() Discover USGS NWIS Stream Gages. …Leaflet. HUC8 Watershed - Georgia State Protected. Darker shading = more elements per unit polygon.Kim Hazırladı : testleri - 6 Mart 2013 at 10:33. Etiketler: 8. sınıf fen ve teknoloji hücre bölünmeleri ve kalıtım test, 8. sınıf fen ve teknoloji hücre bölünmeleri ve kalıtım testi çöz, 8. …Instead of calculating the entire boundary, APPEND will merge the boundary of the new raster datasets with the existing boundary. OVERWRITE — Recompute the boundary in its entirety. APPEND — Append the perimeter of footprints to the existing boundary. This can save time when adding additional raster data to the mosaic dataset, as the entire ...Apr 22, 2017 · The Watershed Boundary Dataset (WBD) is a comprehensive aggregated collection of hydrologic unit (HU) data consistent with the national criteria for delineation and resolution. It defines the areal extent of surface water drainage to a point except in coastal or lake front areas where there could be multiple outlets as … HUC8 Scale Indicator Data by EPA Region - Updated May 2020. WSIO HUC8 Indicator Data for EPA Region 1 (includes CT, ME, MA, NH, RI, VT) (xlsx) WSIO HUC8 Indicator Data for EPA Region 2 (includes NJ, NY) (xlsx) WSIO HUC8 Indicator Data for EPA Region 3 (includes PA, WV, VA, MD, DE, DC) (xlsx)The goal of the Iowa BMP (Best Management Practices) Mapping Project is to provide a complete baseline set of BMPs dating from the 2007-2010 timeframe for use in watershed modeling, historic occurrence, and future practice tracking. The BMPs mapped are: Terraces, Water and Sediment Control Basins (WASCOB), Grassed Waterways, Pond …Leaflet. HUC8 Watershed - Georgia State Protected. Darker shading = more elements per unit polygon.This algorithm is based on the fact that H.C.F. of two numbers divides their difference as well. In this algorithm, we divide the greater by smaller and take the remainder. Now, divide the smaller by this remainder. Repeat until the remainder is 0. For example, if we want to find the H.C.F. of 54 and 24, we divide 54 by 24. The remainder is 6.From Tasks Tab choose a Landscape type to Query. This query will return the Average Percent Landscape Type of your choice across all HUC8s in Pennsylvania. Enter the Attribute Criteria Values for the Average Landscape Percentage you wish to search for. In this case, we will search for HUC8's with Average Percent Forested Land between 70 - 80%. ….

From Tasks Tab choose a Landscape type to Query. This query will return the Average Percent Landscape Type of your choice across all HUC8s in Pennsylvania. Enter the Attribute Criteria Values for the Average Landscape Percentage you wish to search for. In this case, we will search for HUC8's with Average Percent Forested Land between 70 - 80%.May 10, 2021 · Each unit is identified by a unique hydrologic unit code (HUC) consisting of two to eight digits based on its classification. This site provides information and data for current and historical hydrologic units, names, and numbers. huc 8, watershed. Bookmarked by 3 Members. HUC 8 watersheds for Western US and SE US.Data Owner: Minnesota Department of Natural Resources (MN DNR) Definition: The Wildlife Action Network (WAN) was developed as part of the 2015-2025 MN Wildlife Action Plan revision. The WAN is made up of ten GIS layers representing quality aquatic and terrestrial habitats across the state of Minnesota.Science in Your Watershed. The key to finding watershed information is the unique 8-digit Hydrologic Unit Code for each watershed. You can also find your watershed from "Science in Your Watershed" by using the Locate Watersheds Map Interface. USGS Water. Science in Your Watershed.Locate Your Watershed. Click on the Map Above to View a Particular Region. • Try the new Watershed Finder Menu Interface. USGS Water. Science in Your Watershed. Surf Your Watershed. Know Your Watershed. HELP! Locate Your Watershed Mapping Interface for Science in Your Watershed of the U.S. Geological Survey.Introduction. Hydrological Simulation Program - FORTRAN (HSPF) is a comprehensive package for simulation of watershed hydrology and water quality for both conventional and toxic organic pollutants. HSPF incorporates watershed-scale ARM and NPS models into a basin-scale analysis framework that includes fate and transport in one …The spherical coordinate system is commonly used in physics.It assigns three numbers (known as coordinates) to every point in Euclidean space: radial distance r, polar angle θ (), and azimuthal angle φ ().The symbol ρ is often used instead of r.. In geometry, a coordinate system is a system that uses one or more numbers, or coordinates, to uniquely …The nhdplusTools package is intended to provide a reusable set of tools to subset, relate data to, and generate network attributes for U.S. NHDPlus data. General, globally applicable functionality has been moved to hydroloom. nhdplusTools implements a data model consistent with both the NHDPlus dataset and the HY_Features data model. Huc8, Huc 8 watershed boundaries of Iowa. Map created by Chant Eicke, EarthView Environmental Inc. Data courtesy Iowa GIS Library. , Architecture. The NHDPlus is a very large dataset. The architecture of this package as it relates to handling data and what dependencies are used will be very important. Web vs Local Data. nhdplusTools offers a mix of web service and local data functionality. Web services have generally been avoided for large processes., 03/20/00 Updated coverage polygon labels with NJPDES labels. Added HUC4, HUC6, HUC8, WREGION, WR-NAME, WMA_NAME and WMNAME items and updated them to DWM specifications. 03/27/00 Added a new HUC11 line to split offshore HUC11 02040302910 in order to add 02040302920. Updated HUCDIV lintypes for altered area. Update HUC14 d_swid codes for 4 polygons., Overview. This dataset is a digital hydrologic unit boundary layer that is at the Subwatershed (12-digit) level. The layer also includes delineations at the Watershed (10-digit) and Subbasin (8-digit) levels. Each basin is identified by a unique Hydrologic Unit Code (HUC), as well a name, at each level. HUCs are identifiers as assigned to basin ..., This system divides the country into 22 regions (2-digit), 245 subregions (4-digit), 405 basins (6-digit), ~2,400 subbasins (8-digit), ~19,000 watersheds (10-digit), and ~105,000 subwatersheds (12-digit). A hierarchical …, Unique identifier. The first eight digits are the WBD_HUC8. The next six digits are randomly assigned, sequential numbers that are unique within a HUC8. Text: True: 14 For event feature classes, this value is the ReachCode on which the event is located. ReachResolution: Source resolution. Long Integer: False, Leaflet. HUC8 Watershed - Georgia State Protected. Darker shading = more elements per unit polygon., ... HUC8. This has also been done across HUC 8 boundaries. The edgematching process entailed clipping the features at the HUC12 boundary and then a staff person ..., The National Hydrography Dataset is available in shapefile and file geodatabase formats. All NHD downloads contain a copy of the corresponding WBD dataset that is current only to the date the NHD dataset was created. Also, an extract containing only streamgages and dams is available. Download the NHD by 4-digit Hydrologic Unit (HU4) - dataset ..., Attribute_Label: HUC8 Attribute_Definition: Eight digit Hydrologic Unit Code Attribute_Definition_Source: NJDEP Attribute_Domain_Values: Unrepresentable_Domain: See database for assigned 8 digit value Attribute: Attribute_Label: HUC11 Attribute_Definition: Eleven Digit Hydrologic Unit Code Attribute_Definition_Source: NJDEP Attribute_Domain_Values:, the HUC8 region of each water quality monitoring location to HUC8 CAFO intensity measure s. As an example, the total phosphorus reading fr om a monitoring location of a surface waterbody in 13, Jul 1, 2021 · where denotes the runoff of the HUC8 basin, and is the stream-gauge observation. is weighted across the stream-gauge observations whose catchment intersects with the HUC8 basin. is the area fraction of the HUC8 basin in the catchment of the stream gauge, and is the area fraction of the stream gauge's catchment in the HUC8 basin. , See full list on water.usgs.gov , 1 Haz 2021 ... HUC 8's – Eau Claire River Watershed highlighted. Page 7. EC River HUC 8 highlighted. HUC 10s within. Page 8. EC River HUC 8 highlighted. HUC ..., HUC8 Scale Indicator Data by EPA Region - Updated May 2020. WSIO HUC8 Indicator Data for EPA Region 1 (includes CT, ME, MA, NH, RI, VT) (xlsx) WSIO HUC8 Indicator Data for EPA Region 2 (includes NJ, NY) (xlsx) WSIO HUC8 Indicator Data for EPA Region 3 (includes PA, WV, VA, MD, DE, DC) (xlsx), A median is computed for a hydrologic unit only if there are at least four streamgages with a k-day average streamflow percentile located within the hydrologic unit. When creating the hydrologic unit map, the cataloging unit (huc8) medians are drawn on top of the accounting unit (huc6) medians; the accounting unit (huc6) medians are drawn on ... , Watershed Locator. USGS The National Map: National Boundaries Dataset, 3DEP Elevation Program, Geographic Names Information System, National Hydrography Dataset, National Land Cover Database, National Structures Dataset, and National Transportation Dataset; USGS Global Ecosystems; U.S. Census Bureau TIGER/Line data; USFS Road Data; …, HUC 8 maps the subbasin level, analogous to medium-sized river basins (about 2200 nationwide, pictured in red in the image); and HUC 12 is a more local sub-watershed level that captures tributary systems (about 90,000 nationwide used by EnviroAtlas to display national metrics for the conterminous U.S.). Things to know before using these data: , Jul 9, 2020 · WSIO indicator data tables containing all active WSIO indicators are also available for download below. The lower 48 states' currently available HUC12 and HUC8 indicator data are split into ten data tables that correspond with EPA Regions 1 through 10. Note that HUC12s and HUC8s that straddle the borders between two regions appear in both ... , Watershed Boundary Dataset 01 -- New England Region 0101 -- St. John 010100 -- St. John 01010001 -- Upper St. John 6650 01010002 -- Allagash 1235 01010003 -- Fish, This dataset shows the extent of the combined study area for the Kansas LiDAR-based playa mapping and assessment projects examined for EPA Award Number CD97743401 and EPA Award Number CD97763601, administered …, The WWCT also tracks credit sales by HUC8 watersheds to ensure consistency with requirements in 2019 Wisconsin Act 59 and provide transparency in mitigation decision-making. The WWCT issues a Request for Proposals (RFP) with available funding and credit needs for new projects on a quarterly schedule (December 1, March 1, June 1, October 1)., Data Basin is a science-based mapping and analysis platform that supports learning, research, and sustainable environmental stewardship., The problem here is that in the subquery you have aliased as M you are doing SELECT *, and the two tables involved in the join both have a Type column. SQL Server is rightfully complaining that it doesn't know which Type column you want to select.. You only use a single type column from your subquery, and the join condition ensures …, data within that FRD, and ultimately redeliver the FRD at the HUC8 extent. The - flood risk datasets corresponding to the revised areas should be compared against the existing data in the FRD from the surrounding unrevised areas for reasonability and agreement. Since many of the flood risk datasets are derived from the regulatory information, it could reasonably …, There are five input .csv tables required to run this code, including tables containing fish community samples linked to the NHDPlusV2.1 dataset, a list of fish species to be modeled, fish range data for USGS HUC8s, HUC8 designations for NHDPlusV2.1 COMIDs, and predictors used in model development. These files are described below., The HUC8, HUC10, and HUC12 datasets are displayed in this map. The HUC is a hierarchical, numeric code that uniquely identifies hydrologic units. Hydrologic units are subdivisions of watersheds nested from largest to smallest areas and are used to organize hydrologic data. HUCs are constructed as follows: The first two digits identify the region, …, The Watershed Boundary Dataset is public information and may be interpreted by all organizations, agencies, units of government, or others based on needs; however, they are responsible for the appropriate application of the data. Federal, State, or local regulatory bodies are not to reassign to the Natural Resources Conservation Service any ..., The National Hydrography Dataset (NHD) represents the water drainage network of the United States with features such as rivers, streams, canals, lakes, ponds, coastline, dams, and streamgages. Note – As of October 1, 2023, the NHD was retired. NHD data will continue to be available, but no longer maintained. The most current data will be …, This system divides the country into 22 regions (2-digit), 245 subregions (4-digit), 405 basins (6-digit), ~2,400 subbasins (8-digit), ~19,000 watersheds (10-digit), and ~105,000 subwatersheds (12-digit). A hierarchical hydrologic unit code (HUC) consisting of 2 additional digits for each level in the hydrologic unit system is used to identify ..., The quality of input data and the process of watershed delineation can affect the accuracy of runoff predictions in watershed modeling. The Upper Mississippi River Basin was selected to evaluate the effects of subbasin and/or hydrologic response unit (HRU) delineations and the density of climate dataset on the simulated streamflow and water …, In contrast, hydrologic units are drainage areas that are delineated so as to nest into a multi-level hierarchical drainage system. Aside from the surface waters that are collected within the boundary of a hydrologic unit, it may also accept water from one or more points outside of the unit’s boundary. The tidal portion of the James River is ..., This system divides the country into 22 regions (2-digit), 245 subregions (4-digit), 405 basins (6-digit), ~2,400 subbasins (8-digit), ~19,000 watersheds (10-digit), and ~105,000 subwatersheds (12-digit). A hierarchical hydrologic unit code (HUC) consisting of 2 additional digits for each level in the hydrologic unit system is used to identify ...