National Hydrography Data - NHD and 3DHP

This zipped file geodatabase contains two feature classes for use in a GIS. California Data Exchange Center (CDEC) is managed by the Department of Water Resources. CDEC provides users access to hydrologic and climate information used to support real-time flood management and water supply needs in California. CDEC flow gaging station locations (points) were added to the NHDPoint feature class of the National Hydrography Dataset by the California NHD stewardship team. One of the feature classes in this file geodatabase is a derivative of the NHDPoint feature class, containing only the CDEC flow gaging station points with attributes from CDEC included. The other feature class represents the station points snapped to NHDFlowlines to aid in flow analysis.

Major Rivers and Creeks in California selected from the NHD in a zipped shapefile format. Resource last updated 1/30/2024. Services for this layer can be found at: https://gis.water.ca.gov/arcgis/rest/services/InlandWaters/NHD_Major_Rivers_and_Creeks/FeatureServer/ https://gis.water.ca.gov/arcgis/rest/services/InlandWaters/NHD_Major_Rivers_and_Creeks/MapServer Shapefile includes a .csv file with the Ftype descriptors, these can be added via a join on the Ftype code. Selecting Only Major Rivers and Creeks in the NHD using ArcMap - from the USGS National Hydrography Dataset Newsletter, Vol. 13, No. 8, June 2014, by Jeff Simley, USGS **Please note that this data is only as complete as the NHD, and there are connectivity issues associated with this method of selection.** The NHD contains a lot of information, but for some applications, particularly those at small scales, it needs to be generalized. One approach is to show only “major rivers” in the NHD. A quick technique to show only the named rivers can easily be done by selecting NHDFlowline GNIS_NAME > ‘0’. See: ftp://nhdftp.usgs.gov/Hydro_Images/BlueRiver_Named_Rivers.jpgTo be even more restrictive, major rivers can be defined as only “double-line” or polygonal rivers, which appear in NHDArea. This is more complicated, and takes a few minutes, but works well. This approach finds the Artificial Path of those polygonal rivers: 1. Find the polygonal rivers: Select by Attributes NHDArea where FType = 460 - Stream/River. 2. Now it is necessary to find the NHDFlowline Artificial Paths of those rivers. Artificial Paths are linked to the polygon they are inside of using the field WBArea_Permanent_Identier. Create the link by doing a relate between NHDFlowline (key WBArea_Permanent_Identifier) and NHDArea (key Permanent_Identifier) 3. Invoke the relationship and select the corresponding NHDFlowlines. 4. For clarity, turn off the NHDArea selected features (the polygonal rivers). 5. Now the candidate artificial paths are selected, but there are two problems: One is that the rivers running through lakes are not selected (which they should be), and two, the “stubs” of the tributary artificial paths have been selected (which are not wanted). 6. Next order of business is to eliminate the minor stubs with no name. Select from selection by Attributes NHDFlowline GNIS_Name > ‘0’. Now only stubs that are named remain. 7. Some of the remaining candidate artificial paths are wanted (the major rivers) and some are not (the named stubs). The named stubs can be eliminated by virtue of the fact that there are very few of them (normally one record per name) and those with low counts can be eliminated. 8. Open the NHDFlowline attribute table. Some records are selected (the remaining candidate list) and some are not (all other flowlines making up “minor rivers”). Summarize the number of records under the field GNIS_Name and write this out as Sum_Output.dbf which you then add to ArcMap. 9. Now the goal is to find the names of the major rivers. These will be rivers with a record count greater than 1. The extraneous non-named stubs have already been eliminated, which helps reduce the load. The next steps will select only records with significant counts, that is, the major rivers. This will allow deselecting the remaining NHDFlowlines and in the process eliminate the named stubs. 10. It is necessary to relate Sum_Output (key GNIS_Name) with NHDFlowline (key GNIS_Name) to make it possible to use the GNIS_NAME’s to select the major rivers in NHDFlowline. 11. Open the Sum_Output table. Note the field Count_GNIS_Name which will be used to count records. This will eliminate named stubs, leaving just the major rivers selected. Create a New Selection, Cnt_GNIS_N > 1. Leave the table open. Note major rivers are selected.Invoke the relationship to select the major rivers. In ArcMap all “major rivers” have been selected, even rivers through lakes. Note: This workflow excludes the American River, so it has been manually added into the dataset.

Major Rivers in California selected from the NHD in a zipped shapefile format. Resource last updated 1/30/2024. Services for this layer can be found at: https://gis.water.ca.gov/arcgis/rest/services/InlandWaters/NHD_Major_Rivers/FeatureServer https://gis.water.ca.gov/arcgis/rest/services/InlandWaters/NHD_Major_Rivers/MapServer Shapefiles include a .csv with the Ftype code descriptors. These descriptors can be joined to the shapefile via a join on the code field. Selecting Only Major Rivers in the NHD using ArcMap - from the USGS National Hydrography Dataset Newsletter, Vol. 13, No. 8, June 2014, by Jeff Simley, USGS **Please note that this data is only as complete as the NHD, and there are connectivity issues associated with this method of selection. We will continue to update this data as USGS releases new versions of the NHD.** The NHD contains a lot of information, but for some applications, particularly those at small scales, it needs to be generalized. One approach is to show only “major rivers” in the NHD. A quick technique to show only the named rivers can easily be done by selecting NHDFlowline GNIS_NAME > ‘0’. To be even more restrictive, major rivers can be defined as only “double-line” or polygonal rivers, which appear in NHDArea. This is more complicated, and takes a few minutes, but works well. This approach finds the Artificial Path of those polygonal rivers: 1. Find the polygonal rivers: Select by Attributes NHDArea where FType = 460 - Stream/River. 2. Now it is necessary to find the NHDFlowline Artificial Paths of those rivers. Artificial Paths are linked to the polygon they are inside of using the field WBArea_Permanent_Identier. Create the link by doing a relate between NHDFlowline (key WBArea_Permanent_Identifier) and NHDArea (key Permanent_Identifier) 3. Invoke the relationship and select the corresponding NHDFlowlines. 4. For clarity, turn off the NHDArea selected features (the polygonal rivers). 5. Now the candidate artificial paths are selected, but there are two problems: One is that the rivers running through lakes are not selected (which they should be), and two, the “stubs”of the tributary artificial paths have been selected (which are not wanted). 6. Next order of business is to eliminate the minor stubs with no name. Select from selection by Attributes NHDFlowline GNIS_Name > ‘0’. Now only stubs that are named remain. 7. Some of the remaining candidate artificial paths are wanted (the major rivers) and some are not (the named stubs). The named stubs can be eliminated by virtue of the fact that there are very few of them (normally one record per name) and those with low counts can be eliminated. 8. Open the NHDFlowline attribute table. Some records are selected (the remaining candidate list) and some are not (all other flowlines making up “minor rivers”). Summarize the number of records under the field GNIS_Name and write this out as Sum_Output.dbf which you then add to ArcMap. 9. Now the goal is to find the names of the major rivers. These will be rivers with a record count greater than 1. The extraneous non-named stubs have already been eliminated, which helps reduce the load. The next steps will select only records with significant counts, that is, the major rivers. This will allow deselecting the remaining NHDFlowlines and in the process eliminate the named stubs. 10. It is necessary to relate Sum_Output (key GNIS_Name) with NHDFlowline (key GNIS_Name) to make it possible to use the GNIS_NAME’s to select the major rivers in NHDFlowline. 1. Open the Sum_Output table. Note the field Count_GNIS_Name which will be used to count records. This will eliminate named stubs, leaving just the major rivers selected. Create a New Selection, Cnt_GNIS_N > 1. Leave the table open. Note major rivers are selected.Invoke the relationship to select the major rivers. In ArcMap all “major rivers” have been selected, even rivers through lakes. 12. Select only those features with "River" in the GNIS Name. Note: This workout omits the American River. It has been manually added to this dataset.

Major lakes and reservoirs in California selected from the NHD in a zipped shapefile format. Developed for use as a cartographic aid at smaller scales. The features for this dataset were selected from the National Hydrography Dataset (NHD) based on size, not on importance to any particular agency. Resource last updated 1/30/2024. Shapefiles include a .csv with the Ftype code descriptors. These descriptors can be joined to the shapefile via a join on the code field. Services for this layer may be found at: https://gis.water.ca.gov/arcgis/rest/services/InlandWaters/NHD_Major_Lakes_and_Reservoirs/FeatureServer https://gis.water.ca.gov/arcgis/rest/services/InlandWaters/NHD_Major_Lakes_and_Reservoirs/MapServer Data were originally developed and supplied by USGS, and last updated on February 20, 2020. Data was downloaded from USGS National Map Staged Products Directory (http://prd-tnm.s3-website-us-west-2.amazonaws.com/?prefix=StagedProducts/Hydrography/NHD/State/HighResolution/GDB/http://prd-tnm.s3-website-us-west-2.amazonaws.com/?prefix=StagedProducts/Hydrography/NHD/State/HighResolution/GDB/) on March 3rd, 2022. In order to display only major lakes and reservoirs, the following definition query was applied to the NHDWaterbody feature class. (FType = 390 And AreaSqKm > 5) Or (FType = 436 And AreaSqKm > 5 And Permanent_Identifier <> 'fa567cba-b37b-48b7-99d8-bd72a110fdbe' And Permanent_Identifier <> 'c5cae0f8-7d44-4149-b7ef-1b5197adc5a0' And Permanent_Identifier <> '120012522') Or GNIS_Name = 'Elderberry Forebay' Or GNIS_Name = 'Castaic Lagoon' Or Permanent_Identifier = '27088117' Or Permanent_Identifier = '27822760' Or GNIS_Name = 'Thermalito Diversion Pool' Or GNIS_Name = 'Los Banos Reservoir' Or GNIS_Name = 'Thermalito Forebay' Or GNIS_Name = 'Lake Piru' Or GNIS_Name = 'Pyramid Lake' Or GNIS_Name = 'Lake Natoma'

Major Rivers and Creeks in California selected from the NHD in a zipped geodatabase format. Resource last updated 1/30/2024. This is the final version, as the NHD is no longer being updated. Services for this layer can be found at: https://gis.water.ca.gov/arcgis/rest/services/InlandWaters/NHD_Major_Rivers_and_Creeks/FeatureServer\ https://gis.water.ca.gov/arcgis/rest/services/InlandWaters/NHD_Major_Rivers_and_Creeks/MapServer Selecting Only Major Rivers and Creeks in the NHD using ArcMap - from the USGS National Hydrography Dataset Newsletter, Vol. 13, No. 8, June 2014, by Jeff Simley, USGS **Please note that this data is only as complete as the NHD, and there are connectivity issues associated with this method of selection.** The NHD contains a lot of information, but for some applications, particularly those at small scales, it needs to be generalized. One approach is to show only “major rivers” in the NHD. A quick technique to show only the named rivers can easily be done by selecting NHDFlowline GNIS_NAME > ‘0’. See: ftp://nhdftp.usgs.gov/Hydro_Images/BlueRiver_Named_Rivers.jpgTo be even more restrictive, major rivers can be defined as only “double-line” or polygonal rivers, which appear in NHDArea. This is more complicated, and takes a few minutes, but works well. This approach finds the Artifical Path of those polygonal rivers: 1. Find the polygonal rivers: Select by Attributes NHDArea where FType = 460 - Stream/River. 2. Now it is necessary to find the NHDFlowline Artificial Paths of those rivers. Artificial Paths are linked to the polygon they are inside of using the field WBArea_Permanent_Identier. Create the link by doing a relate between NHDFlowline (key WBArea_Permanent_Identifier) and NHDArea (key Permanent_Identifier) 3. Invoke the relationship and select the corresponding NHDFlowlines. 4. For clarity, turn off the NHDArea selected features (the polygonal rivers). 5. Now the candidate artificial paths are selected, but there are two problems: One is that the rivers running through lakes are not selected (which they should be), and two, the “stubs”of the tributary artificial paths have been selected (which are not wanted). 6. Next order of business is to eliminate the minor stubs with no name. Select from selection by Attributes NHDFlowline GNIS_Name > ‘0’. Now only stubs that are named remain. 7. Some of the remaining candidate artificial paths are wanted (the major rivers) and some are not (the named stubs). The named stubs can be eliminated by virtue of the fact that there are very few of them (normally one record per name) and those with low counts can be eliminated. 8. Open the NHDFlowline attribute table. Some records are selected (the remaining candidate list) and some are not (all other flowlines making up “minor rivers”). Summarize the number of records under the field GNIS_Name and write this out as Sum_Output.dbf which you then add to ArcMap. 9. Now the goal is to find the names of the major rivers. These will be rivers with a record count greater than 1. The extraneous non-named stubs have already been eliminated, which helps reduce the load. The next steps will select only records with significant counts, that is, the major rivers. This will allow deselecting the remaining NHDFlowlines and in the process eliminate the named stubs. 10. It is necessary to relate Sum_Output (key GNIS_Name) with NHDFlowline (key GNIS_Name) to make it possible to use the GNIS_NAME’s to select the major rivers in NHDFlowline. 11. Open the Sum_Output table. Note the field Count_GNIS_Name which will be used to count records. This will eliminate named stubs, leaving just the major rivers selected. Create a New Selection, Cnt_GNIS_N > 1. Leave the table open. Note major rivers are selected.Invoke the relationship to select the major rivers. In ArcMap all “major rivers” have been selected, even rivers through lakes. Note: This workflow excludes the American River, so it has been manually added into the dataset.

Major Rivers in California selected from the NHD in a zipped shapefile format. Resource last updated 1/30/2024. Services for this layer can be found at: https://gis.water.ca.gov/arcgis/rest/services/InlandWaters/NHD_Major_Rivers/FeatureServer https://gis.water.ca.gov/arcgis/rest/services/InlandWaters/NHD_Major_Rivers/MapServer Selecting Only Major Rivers in the NHD using ArcMap - from the USGS National Hydrography Dataset Newsletter, Vol. 13, No. 8, June 2014, by Jeff Simley, USGS **Please note that this data is only as complete as the NHD, and there are connectivity issues associated with this method of selection. We will continue to update this data as USGS releases new versions of the NHD.** The NHD contains a lot of information, but for some applications, particularly those at small scales, it needs to be generalized. One approach is to show only “major rivers” in the NHD. A quick technique to show only the named rivers can easily be done by selecting NHDFlowline GNIS_NAME > ‘0’. To be even more restrictive, major rivers can be defined as only “double-line” or polygonal rivers, which appear in NHDArea. This is more complicated, and takes a few minutes, but works well. This approach finds the Artificial Path of those polygonal rivers: 1. Find the polygonal rivers: Select by Attributes NHDArea where FType = 460 - Stream/River. 2. Now it is necessary to find the NHDFlowline Artificial Paths of those rivers. Artificial Paths are linked to the polygon they are inside of using the field WBArea_Permanent_Identier. Create the link by doing a relate between NHDFlowline (key WBArea_Permanent_Identifier) and NHDArea (key Permanent_Identifier) 3. Invoke the relationship and select the corresponding NHDFlowlines. 4. For clarity, turn off the NHDArea selected features (the polygonal rivers). 5. Now the candidate artificial paths are selected, but there are two problems: One is that the rivers running through lakes are not selected (which they should be), and two, the “stubs”of the tributary artificial paths have been selected (which are not wanted). 6. Next order of business is to eliminate the minor stubs with no name. Select from selection by Attributes NHDFlowline GNIS_Name > ‘0’. Now only stubs that are named remain. 7. Some of the remaining candidate artificial paths are wanted (the major rivers) and some are not (the named stubs). The named stubs can be eliminated by virtue of the fact that there are very few of them (normally one record per name) and those with low counts can be eliminated. 8. Open the NHDFlowline attribute table. Some records are selected (the remaining candidate list) and some are not (all other flowlines making up “minor rivers”). Summarize the number of records under the field GNIS_Name and write this out as Sum_Output.dbf which you then add to ArcMap. 9. Now the goal is to find the names of the major rivers. These will be rivers with a record count greater than 1. The extraneous non-named stubs have already been eliminated, which helps reduce the load. The next steps will select only records with significant counts, that is, the major rivers. This will allow deselecting the remaining NHDFlowlines and in the process eliminate the named stubs. 10. It is necessary to relate Sum_Output (key GNIS_Name) with NHDFlowline (key GNIS_Name) to make it possible to use the GNIS_NAME’s to select the major rivers in NHDFlowline. 1. Open the Sum_Output table. Note the field Count_GNIS_Name which will be used to count records. This will eliminate named stubs, leaving just the major rivers selected. Create a New Selection, Cnt_GNIS_N > 1. Leave the table open. Note major rivers are selected.Invoke the relationship to select the major rivers. In ArcMap all “major rivers” have been selected, even rivers through lakes. 12. Select only those features with "River" in the GNIS Name. Note: This workout omits the American River. It has been manually added to this dataset.

Major lakes and reservoirs in California selected from the NHD in a zipped shapefile format. Developed for use as a cartographic aid at smaller scales. The features for this dataset were selected from the National Hydrography Dataset (NHD) based primarily on size. Resource last updated 1/30/2024. Services for this layer may be found at: https://gis.water.ca.gov/arcgis/rest/services/InlandWaters/NHD_Major_Lakes_and_Reservoirs/FeatureServer https://gis.water.ca.gov/arcgis/rest/services/InlandWaters/NHD_Major_Lakes_and_Reservoirs/MapServer Data were originally developed and supplied by USGS, and last updated on February 20, 2020. Data was downloaded from USGS National Map Staged Products Directory (http://prd-tnm.s3-website-us-west-2.amazonaws.com/?prefix=StagedProducts/Hydrography/NHD/State/HighResolution/GDB/http://prd-tnm.s3-website-us-west-2.amazonaws.com/?prefix=StagedProducts/Hydrography/NHD/State/HighResolution/GDB/) on March 3rd, 2022. In order to display only major lakes and reservoirs, the following definition query was applied to the NHDWaterbody feature class. (FType = 390 And AreaSqKm > 5) Or (FType = 436 And AreaSqKm > 5 And Permanent_Identifier <> 'fa567cba-b37b-48b7-99d8-bd72a110fdbe' And Permanent_Identifier <> 'c5cae0f8-7d44-4149-b7ef-1b5197adc5a0' And Permanent_Identifier <> '120012522') Or GNIS_Name = 'Elderberry Forebay' Or GNIS_Name = 'Castaic Lagoon' Or Permanent_Identifier = '27088117' Or Permanent_Identifier = '27822760' Or GNIS_Name = 'Thermalito Diversion Pool' Or GNIS_Name = 'Los Banos Reservoir' Or GNIS_Name = 'Thermalito Forebay' Or GNIS_Name = 'Lake Piru' Or GNIS_Name = 'Pyramid Lake' Or GNIS_Name = 'Lake Natoma'

Major Rivers and Creeks in California selected from the NHD in a geopackage format. Resource last updated 1/30/2024. Services for this layer can be found at: https://gis.water.ca.gov/arcgis/rest/services/InlandWaters/NHD_Major_Rivers_and_Creeks/FeatureServer/ https://gis.water.ca.gov/arcgis/rest/services/InlandWaters/NHD_Major_Rivers_and_Creeks/MapServer Selecting Only Major Rivers and Creeks in the NHD using ArcMap - from the USGS National Hydrography Dataset Newsletter, Vol. 13, No. 8, June 2014, by Jeff Simley, USGS **Please note that this data is only as complete as the NHD, and there are connectivity issues associated with this method of selection. We will continue to update this data as USGS releases new versions of the NHD.** The NHD contains a lot of information, but for some applications, particularly those at small scales, it needs to be generalized. One approach is to show only “major rivers” in the NHD. A quick technique to show only the named rivers can easily be done by selecting NHDFlowline GNIS_NAME > ‘0’. See: ftp://nhdftp.usgs.gov/Hydro_Images/BlueRiver_Named_Rivers.jpgTo be even more restrictive, major rivers can be defined as only “double-line” or polygonal rivers, which appear in NHDArea. This is more complicated, and takes a few minutes, but works well. This approach finds the Artifical Path of those polygonal rivers: 1. Find the polygonal rivers: Select by Attributes NHDArea where FType = 460 - Stream/River. 2. Now it is necessary to find the NHDFlowline Artificial Paths of those rivers. Artificial Paths are linked to the polygon they are inside of using the field WBArea_Permanent_Identier. Create the link by doing a relate between NHDFlowline (key WBArea_Permanent_Identifier) and NHDArea (key Permanent_Identifier) 3. Invoke the relationship and select the corresponding NHDFlowlines. 4. For clarity, turn off the NHDArea selected features (the polygonal rivers). 5. Now the candidate artificial paths are selected, but there are two problems: One is that the rivers running through lakes are not selected (which they should be), and two, the “stubs”of the tributary artificial paths have been selected (which are not wanted). 6. Next order of business is to eliminate the minor stubs with no name. Select from selection by Attributes NHDFlowline GNIS_Name > ‘0’. Now only stubs that are named remain. 7. Some of the remaining candidate artificial paths are wanted (the major rivers) and some are not (the named stubs). The named stubs can be eliminated by virtue of the fact that there are very few of them (normally one record per name) and those with low counts can be eliminated. 8. Open the NHDFlowline attribute table. Some records are selected (the remaining candidate list) and some are not (all other flowlines making up “minor rivers”). Summarize the number of records under the field GNIS_Name and write this out as Sum_Output.dbf which you then add to ArcMap. 9. Now the goal is to find the names of the major rivers. These will be rivers with a record count greater than 1. The extraneous non-named stubs have already been eliminated, which helps reduce the load. The next steps will select only records with significant counts, that is, the major rivers. This will allow deselecting the remaining NHDFlowlines and in the process eliminate the named stubs. 10. It is necessary to relate Sum_Output (key GNIS_Name) with NHDFlowline (key GNIS_Name) to make it possible to use the GNIS_NAME’s to select the major rivers in NHDFlowline. 11. Open the Sum_Output table. Note the field Count_GNIS_Name which will be used to count records. This will eliminate named stubs, leaving just the major rivers selected. Create a New Selection, Cnt_GNIS_N > 1. Leave the table open. Note major rivers are selected.Invoke the relationship to select the major rivers. In ArcMap all “major rivers” have been selected, even rivers through lakes. Note: This workflow excludes the American River, so it has been manually added into the dataset.

Major Rivers in California selected from the NHD in a geopackage format. Resource last updated 1/30/2024.This is the final version. The NHD is now a static dataset Services for this layer can be found at: https://gis.water.ca.gov/arcgis/rest/services/InlandWaters/NHD_Major_Rivers/FeatureServer https://gis.water.ca.gov/arcgis/rest/services/InlandWaters/NHD_Major_Rivers/MapServer Selecting Only Major Rivers in the NHD using ArcMap - from the USGS National Hydrography Dataset Newsletter, Vol. 13, No. 8, June 2014, by Jeff Simley, USGS **Please note that this data is only as complete as the NHD, and there are connectivity issues associated with this method of selection. We will continue to update this data as USGS releases new versions of the NHD.** The NHD contains a lot of information, but for some applications, particularly those at small scales, it needs to be generalized. One approach is to show only “major rivers” in the NHD. A quick technique to show only the named rivers can easily be done by selecting NHDFlowline GNIS_NAME > ‘0’. To be even more restrictive, major rivers can be defined as only “double-line” or polygonal rivers, which appear in NHDArea. This is more complicated, and takes a few minutes, but works well. This approach finds the Artificial Path of those polygonal rivers: 1. Find the polygonal rivers: Select by Attributes NHDArea where FType = 460 - Stream/River. 2. Now it is necessary to find the NHDFlowline Artificial Paths of those rivers. Artificial Paths are linked to the polygon they are inside of using the field WBArea_Permanent_Identier. Create the link by doing a relate between NHDFlowline (key WBArea_Permanent_Identifier) and NHDArea (key Permanent_Identifier) 3. Invoke the relationship and select the corresponding NHDFlowlines. 4. For clarity, turn off the NHDArea selected features (the polygonal rivers). 5. Now the candidate artificial paths are selected, but there are two problems: One is that the rivers running through lakes are not selected (which they should be), and two, the “stubs”of the tributary artificial paths have been selected (which are not wanted). 6. Next order of business is to eliminate the minor stubs with no name. Select from selection by Attributes NHDFlowline GNIS_Name > ‘0’. Now only stubs that are named remain. 7. Some of the remaining candidate artificial paths are wanted (the major rivers) and some are not (the named stubs). The named stubs can be eliminated by virtue of the fact that there are very few of them (normally one record per name) and those with low counts can be eliminated. 8. Open the NHDFlowline attribute table. Some records are selected (the remaining candidate list) and some are not (all other flowlines making up “minor rivers”). Summarize the number of records under the field GNIS_Name and write this out as Sum_Output.dbf which you then add to ArcMap. 9. Now the goal is to find the names of the major rivers. These will be rivers with a record count greater than 1. The extraneous non-named stubs have already been eliminated, which helps reduce the load. The next steps will select only records with significant counts, that is, the major rivers. This will allow deselecting the remaining NHDFlowlines and in the process eliminate the named stubs. 10. It is necessary to relate Sum_Output (key GNIS_Name) with NHDFlowline (key GNIS_Name) to make it possible to use the GNIS_NAME’s to select the major rivers in NHDFlowline. 1. Open the Sum_Output table. Note the field Count_GNIS_Name which will be used to count records. This will eliminate named stubs, leaving just the major rivers selected. Create a New Selection, Cnt_GNIS_N > 1. Leave the table open. Note major rivers are selected.Invoke the relationship to select the major rivers. In ArcMap all “major rivers” have been selected, even rivers through lakes. 12. Select only those features with "River" in the GNIS Name. Note: This workflow omits the American River. It has been manually added to this dataset.

Major lakes and reservoirs in California selected from the NHD in a geopackage format. Developed for use as a cartographic aid at smaller scales. The features for this dataset were selected from the National Hydrography Dataset (NHD) based on size, not on importance to any particular agency. Resource last updated 1/30/2024. Services for this layer may be found at: https://gis.water.ca.gov/arcgis/rest/services/InlandWaters/NHD_Major_Lakes_and_Reservoirs/FeatureServer https://gis.water.ca.gov/arcgis/rest/services/InlandWaters/NHD_Major_Lakes_and_Reservoirs/MapServer Data were originally developed and supplied by USGS, and last updated on February 20, 2020. Data was downloaded from USGS National Map Staged Products Directory (http://prd-tnm.s3-website-us-west-2.amazonaws.com/?prefix=StagedProducts/Hydrography/NHD/State/HighResolution/GDB/http://prd-tnm.s3-website-us-west-2.amazonaws.com/?prefix=StagedProducts/Hydrography/NHD/State/HighResolution/GDB/) on March 3rd, 2022. In order to display only major lakes and reservoirs, the following definition query was applied to the NHDWaterbody feature class. (FType = 390 And AreaSqKm > 5) Or (FType = 436 And AreaSqKm > 5 And Permanent_Identifier <> 'fa567cba-b37b-48b7-99d8-bd72a110fdbe' And Permanent_Identifier <> 'c5cae0f8-7d44-4149-b7ef-1b5197adc5a0' And Permanent_Identifier <> '120012522') Or GNIS_Name = 'Elderberry Forebay' Or GNIS_Name = 'Castaic Lagoon' Or Permanent_Identifier = '27088117' Or Permanent_Identifier = '27822760' Or GNIS_Name = 'Thermalito Diversion Pool' Or GNIS_Name = 'Los Banos Reservoir' Or GNIS_Name = 'Thermalito Forebay' Or GNIS_Name = 'Lake Piru' Or GNIS_Name = 'Pyramid Lake' Or GNIS_Name = 'Lake Natoma'

This is a spreadsheet used to record the datasets used for reference in the updating of the California portion of the NHD. The NHD Stewardship Program is constantly seeking new sources of local knowledge to help improve this data. To contribute to this effort, please contact the lead steward at nhd_stewardship@water.ca.gov