{ "culture": "en-US", "name": "", "guid": "", "catalogPath": "", "snippet": "This dataset includes polygons associated with each Groundwater Flow System in Nevada created by merging the Hydrographic Areas (HA) associated with each flow system. The two associated datasets with these polygon data include boundary line data for each flow system describing its delineation source and status and the HA polygons associated with each system.", "description": "

Hydrographic areas (HA) or hydrographic basins in Nevada were delineated by the U.S. Geological Survey (USGS) and Nevada Division of Water Resources in the late 1960s (Cardinalli and others, 1968; Rush, 1968) for scientific and administrative purposes. In 1988, the USGS published Hydrologic Atlas 694-C where the hydrographic areas of Nevada delineated in the 1960's (and hydrographic areas from surrounding states) were used to define the groundwater flow systems of the Great Basin (Harrill and others, 1988). These data were digitized and released in GIS format by the USGS in 2009 (Buto and Reichelt, 2009). <\/SPAN><\/P>

As part of the Nevada Water Initiative project, NDWR has updated the 2009 USGS dataset to include flow systems occurring within the State of Nevada that were previously excluded because they were outside of the Great Basin region. Additionally, NDWR has updated existing HAs overlapping the state boundary with adjacent states HUC boundaries to form more hydrologically based units. Within the State of Nevada, the 1:1,000,000-scale HAs digitized by the USGS were spatially joined to the 1:750,000-scale hydrographic areas used by NDWR for administering water rights in the State and the groundwater flow system attributes were transferred from the USGS dataset to the NDWR HAs. Outside of the State, the 1,000,000-scale HAs were spatially joined to the corresponding USGS 10-Digit Hydrologic Units (HUC10) which overlapped with each HA. Along the State boundary, the 1:750,000-scale NDWR HAs were merged with the rest of the hydrologically continuous basin (as a HUC10 boundary) that exist adjacent to the State. In the NDWR HAs where there was no corresponding groundwater flow system delineated by the USGS, each HA was assigned a flow system based on the following: <\/SPAN><\/P>

  • Within the Truckee, Carson, Walker, and Colorado River systems, several NDWR HAs adjacent to the Nevada State boundary were excluded from the original dataset. Based on the known watersheds of these surface water systems, previously delineated NDWR HAs were assigned to the groundwater flow system based on the watershed boundary.<\/SPAN><\/P><\/LI>

  • Along the northern border of Nevada with Idaho and Oregon, NDWR HAs belonging to tributary watersheds of the Snake River basin were assigned groundwater flow systems based on watershed area. These systems include those belonging to the Owyhee River, Bruneau River, Salmon Falls Creek, and Goose Creek. <\/SPAN><\/P><\/LI>

  • Along the northwestern border of Nevada with Oregon and California, small portions of several endorheic basins within the adjacent states extend into Nevada. Due to the potentially complex nature of these groundwater flow systems, the NDWR HAs associated with these endorheic basins were assigned an 'Undetermined' groundwater flow system and may be revisited as part of the Nevada Water Initiative in the future.<\/SPAN><\/P><\/LI><\/UL>

    To document the delineation source and status of each groundwater flow system boundary, a line dataset was produced categorizing each boundary into one of five types: 1. Delineated by NDWR, 2. Delineated by NDWR, Extends Beyond Area Shown, 3. Delineated by USGS, 4. Delineated by USGS, Modified by NDWR, and 5. Undetermined. The Nevada State boundary was also included with these data to better show where the HA data source was merged from the NDWR HAs to the USGS HUC10 boundaries. A polygon dataset of all groundwater flow systems was also created by merging all the HAs and HUC10 boundaries associated with each flow system into a single polygon. Each dataset includes the following attributes:<\/SPAN><\/P>

    • Hydrographic Basin-scale polygons: NDWR Basin Number (ID), NDWR Basin Name, NDWR Basin Sub-Area Name, Groundwater Flow System ID, Groundwater Flow System Name, Groundwater Flow System Source, and Polygon Data Source (NDWR HA or USGS HUC10) <\/SPAN><\/P><\/LI>

    • Boundary lines: boundary type<\/SPAN><\/P><\/LI>

    • Flow system scale polygons: Groundwater Flow System Number (ID), Groundwater Flow System Name, and Groundwater Flow System Source <\/SPAN><\/P><\/LI><\/UL>

      Known issues associated with these data include the following:<\/SPAN><\/P>

      • The boundaries of the NDWR HA and the USGS HUC10 datasets do not necessarily align where they were merged along the Nevada State border. This results in apparent jogs in the boundaries along the State border where the data source switches.<\/SPAN><\/P><\/LI>

      • Along the border with Oregon, the three NDWR HAs of Macy Flat, Guano Valley, and Sage Hen Valley (HAs 010, 006, and 005 respectively) align with two HUC10 boundaries in Oregon and could not be merged with the associated HUC10s without removing one of the NDWR HAs.<\/SPAN><\/P><\/LI>

      • The extents of the bordering endorheic basin flow systems have not been determined.<\/SPAN><\/P><\/LI>

      • The southern extent of the Owens River system is known to extend beyond the delineated boundary.<\/SPAN><\/P><\/LI><\/UL>

        References Cited:<\/SPAN><\/P>

        1. Buto, S.G. and Reichelt, J.C., 2009, 1:1,000,000-scale Hydrographic Areas of the Great Basin: U.S. Geological Survey data release, https://doi.org/10.5066/P9VCBUAU<\/SPAN><\/P><\/LI>

        2. Cardinalli, J.L., Roach, L.M., Rush, F.E., and Vasey, B.J., 1968, State of Nevada hydrographic areas, scale 1:500,000, in Rush, F.E., ed., Index of hydrographic areas: Nevada Division of Water Resources Information Report 6, 38 p, http://images.water.nv.gov/images/publications/Information%20series/6.pdf<\/SPAN><\/P><\/LI>

        3. Harrill, J.R., Gates, J.S., and Thomas, J.M., 1988, Major ground-water flow systems in the Great Basin region of Nevada, Utah, and adjacent states: U.S. Geological Survey Hydrologic Investigations Atlas HA-694-C, scale 1:1,000,000, 2 sheets, https://doi.org/10.3133/ha694C<\/SPAN><\/P><\/LI><\/OL><\/DIV><\/DIV><\/DIV>", "summary": "This dataset includes polygons associated with each Groundwater Flow System in Nevada created by merging the Hydrographic Areas (HA) associated with each flow system. The two associated datasets with these polygon data include boundary line data for each flow system describing its delineation source and status and the HA polygons associated with each system.", "title": "Nevada Groundwater Flow Systems", "tags": [ "groundwater", "basin", "nevada", "ndwr", "hydrographic", "flow", "interbasin", "system", "ndwr", "valley", "region", "boundary", "huc10", "huc8", "hydrologic", "unit", "code", "great basin" ], "type": "", "typeKeywords": [], "thumbnail": "", "url": "", "minScale": 500000, "maxScale": 5000, "spatialReference": "", "accessInformation": "Nevada Water Initiative, Office of the State Engineer, Nevada Division of Water Resources, Department of Conservation and Natural Resources. Authors: Vergin, T.N., and Allander, K.K.\n\nInitial Release: November x, 2024\n\nCarson City Office (Main Office)\n901 S. Stewart St., Suite 2002\nCarson City, NV 89701\nOffice Phone: (775) 684-2800\nOffice Fax: (775) 684-2811\nOffice Hours: Mon - Fri 8:00 am - 5:00 pm", "licenseInfo": "

          None<\/SPAN><\/P><\/DIV><\/DIV><\/DIV>", "portalUrl": "" }