TO: Users of the National Hydrography Dataset (NHD) in California
USGS has informed us that they are experiencing some technical problems with their staged NHD products that are available for public download from their website: https://www.usgs.gov/core-science-systems/ngp/national-hydrography/access-national-hydrography-products – scroll down the page to the “Download by Link” section. The products affected are the state extracts and the 8-digit Hydrologic Units (HU8) datasets.
Normally the state extracts are refreshed four times per year, but since June of 2020 this has not been happening. The June 2020 version is still available for download, but it does not reflect the improvements we have made since that time. These improvements are reflected in the HU8 downloads, but unfortunately there is a separate problem with the HU8 datasets. These Hydrography Dataset feature classes contain duplicate features. These can be removed using the Delete Identical tool in ArcGIS which requires an Advanced license. The Watershed Boundary Dataset feature classes are unaffected by this problem.
The problem with the state extracts will persist while USGS develops a new process; there is no expected resolution date at this time. Your state steward is developing a workaround for those who need a whole-state copy of the NHD, but it won’t be ready until sometime in April. The problem with the duplicated features in the HU8 products is expected to be resolved in time for the April refresh cycle, check back on the website around the middle of the month. USGS apologizes for this inconvenience.
If you have any questions about this, or about the NHD in general, please contact the California NHD steward Jane.Schafer-Kramer@water.ca.gov.