Known Issues with NHDPlus HR Datasets

 Unresolved known issues in the NHDPlus HR Datasets

 Below are unresolved issues identified in the NHDPlus HR datasets which do not need further reporting.

• Spatial Index Issues - NHDPlus HR staged products distributed in March 2021 or later may exhibit problems with features disappearing at different display scales in ArcGIS versions prior to 10.7.1. The spatial index may appear to be corrupted or missing. To work around this issue, see the Esri documentation: Rebuild a spatial index—ArcGIS Help | ArcGIS Desktop (added 4/21/2021).
• EROM flow estimate missing - No EROM flow estimates are present for hydrologic units in Regions 20, 21, and 22 due to a lack of precursory data to perform these calculations. Missing data from the following tables: NHDPlusEROMMA, NHDPlusEROMQAMA, NHDPlusEROMQARPT, NHDPlusIncrLat, NHDPlusIncrPrecipMM01-12, and NHDPlusIncrTempMM01-12.  These data will be included in subsequent NHDPlus HR dataset versions when appropriate input information is available. (added 4/19/2021)
• Maximum values not a main outflow - Maximum values found in the fac.tif raster don’t represent a main outflow. This is due to coastline artificial path flow routing. This error will be corrected and addressed in subsequent NHDPlus HR dataset versions. Affected vector processing units: 0407, 0408, 0409, 0420, 0421, 0422, 0423, 0424i, 0425, 0410, 0411, 0412, 0413, 0414, 0426i, 0427, 0428i. (added 4/19/2021)
• Catchment errors – NHDPlusCatchments extend or fall short of HUC4 WBD boundaries in Region 04. Catchments may have holes, overlap, or be improperly assigned. Holes are present in the NHDPlusCatchment layer for vector processing units 0420 where NODATA exists. This error will be corrected and addressed in subsequent NHDPlus HR dataset versions. (added 2/22/2021)
• Value Added Attributes (VAA) Errors - Not all VAA’s between inflowing and outflowing features carry over properly for vector processing units in Region 04. This error will be corrected in the National NHDPlus HR release. Affected vector processing units: 0407, 0408, 0409, 0416, 0417, 0418i, 0419i, 0420, 0421, 0422, 0423, 0424, 0424i, 0411, 0412, 0413, 0414, 0426, 0426i, 0427, 0428, 0429, 0428i. (added 4/19/2021)
• Misalignment between elevation raster data and Elev_clip feature class -  Due to a lack of source data over oceans, the elev_clip feature class does not align with raster data for vector processing units 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2101, 2102, 2201, and 2203. This is due to missing source data and will not be addressed in subsequent releases. (added 4/19/2021)
• 7-Zip Issue with NHD National Products - An issue exists with unzipping NHD National products using 7-zip software. NHD National products unzipped using 7-zip software will return a ‘header error’ message shortly after starting the unzipping process. This is a known issue with the 7-zip software and remains unresolved at this time. Please utilize Windows Extract, or any other software of your choosing, to unzip this product. (added 6/16/2020)
• Errors in raster data - An error during the NHDPlus HR build process resulted in incorrect catchment raster data (cat.tif) for HU 19020302, creating a seam between this raster and adjacent hydrologic units. All rasters in this hydrologic unit have incorrect projection information (CONUS Albers) and should be re-projected into Alaska Albers. These errors will be corrected and addressed in subsequent NHDPlus HR dataset versions. (Added 4/29/2020)
• Lack of network connectivity - Poor network connectivity found throughout NHDPlus HR HU4 0713 and 0404 as the result of many disconnected flowlines and micrograps. These issues will be addressed in subsequent NHDPlus HR dataset versions. (added 4/20/2020)
• Missing elev_meta polygon (raster data affected) - This error is present in hydrological unit 2101 and affects all raster data. A missing polygon has been identified within the elev_meta feature class . The issue is due to a lack of source data in this area and thus cannot be resolved. This error will be corrected and addressed in subsequent NHDPlus HR dataset versions. (added 4/10/2020)

• Unpopulated flow accumulation raster - The flow accumulation raster, fac.tif was previously not included for HU4 1027. A software issue caused the NHDPlus HR Build tool to fail for these processing units. This dataset also has an empty NHDPlusMegaDiv table. These issues will be corrected in subsequent NHDPlus HR dataset versions. (added 2/20/2020)

• Missing, overlapping, or noncontiguous elev_meta polygons (raster data not affected) - An issue has been identified affecting some polygons in the elev_meta feature class. All related raster files are unaffected. This error is present in, but may not limited to, the following vector processing units: Region 04, 0508, 0713, 1107, and 1711. This error will potentially affect subsequent NHDPlus HR dataset versions, depending on the source elevation data. (updated 4/19/2019, originally posted 1/22/2020)
• 0808 Dendritic Network – This unit would not process through the NHDPlus HR build software due to its highly complicated network. The only workable solution found to date is to set all flowlines having Divergence=2 (except for one at a VPU connection) to InNetwork=0 when processing the unit. In effect, this made the network dendritic, and much simpler than the original NHD data. We will attempt to correct this issue in subsequent NHDPlus HR dataset versions. (added 10/22/19)
• NHDPlusBurnLineEvent BurnLenKM - An issue has been identified affecting the BurnLenKM attribute in the NHDPlusBurnLineEvent feature class for 1705. The BurnLenKM attribute is incorrectly displaying the Length in Kilometers, this is due to an issue with the LengthKM from the NHDFlowline feature class. This error will be corrected and addressed in subsequent NHDPlus HR dataset versions. (added 8/13/2018)
• NHDPlusLandSea domain - An issue has been identified affecting all NHDPlusLandSea domains. Negative 2 values are not shown as Sea features. This error will be corrected and addressed in subsequent NHDPlus HR dataset versions. (added 7/17/2018)
• Metadata - Some inaccuracies have been identified in the NHDPlus HR metadata. These errors will be updated in subsequent NHDPlus HR dataset versions with a future model change. (added 4/3/2018)
• The 3DEP and WBD snapshot dates for vector processing units are not accurate. These were included as place holders when the metadata template was being developed and have not been updated for the beta metadata.
• The processing software version may not be up to date for the beta version of the dataset.
• For the HU4 level, a statement is included that network connectivity was verified by tracing upstream from all outlets. This statement is being evaluated and will be modified.
• The NHD source criteria scale will be modified from 1:24,000 to 1:24,000 or better.
• An issue has been identified affecting all NHDPlus HR XML Metadata products created after August 13, 2018. Links within the metadata describing where NHDPlus HR Beta raster products are located in order for download are incorrect. This is making the raster data not downloadable in ScienceBase and The National Map Viewer. (added 9/7/2018)
• NHDPlusLandSea domain - An issue has been identified affecting all NHDPlusLandSea domains. Negative 2 values are not shown as Sea features. This error will be corrected and addressed in subsequent NHDPlus HR dataset versions. (added 7/17/2018)
• Incorrectly named coordinate systems - Some CONUS NHDPlus HR raster file projections are incorrectly named NAD_1983_Albers, although the projection projection parameters within the file are correctly defined as USA Contiguous Albers Equal Area Conic USGS Version. To resolve the naming issue, use the Esri ArcToolbox Define Projection tool and select USA_Contiguous_Albers_Equal_Area_Conic_USGS_version for the coordinate system. This issue will be corrected in subsequent NHDPlus HR dataset versions. (added 3/29/2018)
• Incorrect PathLength - An issue has been identified affecting PathLength in the NHDPlusFlowlineVAA table. This source of this issue is incorrect LengthKM values on some NHDFlowline features. This issue affects the following NHDPlus HR datasets: Regions 07, 10, 14, and 15. The source of the error has been corrected for the affected NHDFlowlines and will be addressed for the previously mentioned Regions in subsequent NHDPlus HR dataset versions. (added 3/19/2018)
• Missing NHDWaterbody catchments - A processing error has been identified which caused some NHDWaterbody features to not be burned and thus have no associated catchments. This issue will only affect a catchment boundary with no wall. This issue could also affect neighboring catchment boundaries. This issue potentially affects Regions 01, 02, 06, 10, 12, 14, 15 and 16. This error has been corrected and will be addressed for the previously mentioned Regions in subsequent NHDPlus HR dataset versions. (added 11/28/2017)
• Incorrect values in NHDPlusIncr Table for specific geographic areas only - In the NHDPlusIncr* table, the MissDataA field has positive values rather than the correct value of “0”. This does not affect EROM, other NHDPlus feature classes, or tables. This issue affects the following NHDPlus HR datasets: 0903, portions of Region 12, Region 14, Region 15, Region 16, Region 02, 0108 and 0110. This issue will be corrected in subsequent NHDPlus HR dataset versions. *monthly mean tables. (added 7/19/2017)
• Excessive sinks in off-network water bodies - A process was inadvertently introduced during the processing of NHDPlus HR datasets for Hydro Regions 02, 07, 10, 12, 14, 15, and 16 that caused sinks to be created in all off-network water bodies. This will be corrected in subsequent NHDPlus HR dataset versions. (added 6/2/2017)
• HU2, HU14, and HU16 Feature classes in WBD Feature Dataset are not populated - HU14 and HU16 features only exist for a few areas. These feature classes will be empty in most datasets. The HU2 feature class was not populated during the creation of initial NHDPlus HR data. These datasets may not include HU2 features. More recent production now includes HU2 features. (added 5/12/2017)

Resolved issues in the NHDPlus HR Datasets

Below are issues identified in the NHDPlus HR datasets which have been resolved.

• RESOLVED - Missing flow accumulation data - No flow accumulation data is present for hydrologic units in Regions 20 and 21 due to a lack of precursory data to perform these calculations. Missing data from the following tables: NHDPlusEROMMA, NHDPlusEROMQAMA, NHDPlusEROMQARPT, NHDPlusIncrLat, NHDPlusIncrPrecipMM01-12, and NHDPlusIncrTempMM01-12. This error will be corrected and addressed in subsequent NHDPlus HR dataset versions. (resolved 4/19/2021, originally posted 4/15/2020)
• RESOLVED -  Incorrect catchments due to zero elevation values - An error during the NHDPlus HR Build process resulting in an incorrect hydrodem caused incorrectly built catchments for HU4s 0714 and 0415. In the hydrodem, the streams were burned correctly, the walls created correctly, and the catchments derived from this hydrodem conformed correctly to the WBD boundaries. However, the topography in between was replaced with a flat surface of zero elevation resulting in incorrect catchment derivation . This issue has been corrected. (resolved 11/07/19, originally posted 10/4/2017)
• RESOLVED - Missing relationship classes - Some NHD relationship classes normally found in the NHD data model are missing in NHDPlus HR Datasets. This issue will be corrected in the future, but existing datasets will not be recreated. (resolved 11/07/19, originally posted 5/12/2017).
• RESOLVED -  Invalid and or missing NHDPlusFlowlineVAA and EROM Tables for  NHDPlus HR datasets: portions of Region 09, Region 10, Region 16 and Sub-region 0108. Within the NHDFlowline feature class, the InNetwork field was improperly set to "NULL". This field is now set to "YES" or "NO" based on the FlowDir field. This issue also caused some VAAs to not be present in the NHDPlusFlowlineVAA table. This issue has been corrected. (resolved 10/29/19, originally posted 10/4/2017)
• RESOLVED - Region 08 preliminary data release - Region 08 was distributed in September 2019 as preliminary data. Region 08 final processing has been completed and the updated data  distributed on October 22, 2019. Any data downloaded prior to October 22, 2019 will have the following conditions (resolved 10/22/19, originally posted 10/15/2019): 
• 0808: three of the 40 total value-added attributes were not fully populated in 0808 (RTNDIV, TOTDA, DivDA), the incremental allocations for Precipitation, Temperature, Runoff, and Latitude were not present, and the EROM flow estimates were not populated.
• 0801-0807: EROM flow estimates were not populated.
• RESOLVED - 0318 reprocessing and redistribution – 0318 has been redistributed due to connection to 0809. This VPU was reprocessed in its entirety.  All identifiers, including NHDPlusID, LevelPathID, TerminalPathID, FromNode, ToNode, and HydrologicSequence have been updated. (resolved 10/22/19, originally posted 10/15/2019)
• RESOLVED - Unpopulated flow accumulation raster - The flow accumulation raster, fac.tif was previously not included for HU4s 0208, 0901, 0903, 1018, 1019, 1025, 1604, and 1606. A software problem caused the NHDPlus HR Build Step P tool to fail for these processing units. Flow accumulation rasters are now available for these HU4s. To confirm access to the updated data packages, reference the <pubdate> provided in the xml files. (updated 5/8/2018)
• RESOLVED - Incorrect files in raster download files - The raster download .7z files sometimes contain the wrong raster files. (resolved 05/25/2017, originally posted 5/25/2017)