National Hydrography Data - NHD and 3DHP

<p style='background-color:rgb(255, 255, 255); box-sizing:border-box; color:rgb(51, 51, 51); font-family:&quot;Helvetica Neue&quot;, Helvetica, Arial, sans-serif; font-size:16px; font-style:normal; font-variant-caps:normal; font-variant-ligatures:normal; font-weight:400; letter-spacing:normal; margin:0px 0px 10px; text-align:start; text-decoration-color:initial; text-decoration-style:initial; text-indent:0px; text-transform:none; word-spacing:0px;'>The USGS National Hydrography Dataset (NHD) downloadable data collection from The National Map (TNM) is a comprehensive set of digital spatial data that encodes information about naturally occurring and constructed bodies of surface water (lakes, ponds, and reservoirs), paths through which water flows (canals, ditches, streams, and rivers), and related entities such as point features (springs, wells, stream gages, and dams). The information encoded about these features includes classification and other characteristics, delineation, geographic name, position and related measures, a "reach code" through which other information can be related to the NHD, and the direction of water flow. The network of reach codes delineating water and transported material flow allows users to trace movement in upstream and downstream directions. In addition to this geographic information, the dataset contains metadata that supports the exchange of future updates and improvements to the data. The NHD supports many applications, such as making maps, geocoding observations, flow modeling, data maintenance, and stewardship. For additional information on NHD, go to <a style='background-color:transparent; box-sizing:border-box; color:rgb(22, 92, 171);' target='_blank' href='https://www.usgs.gov/core-science-systems/ngp/national-hydrography' rel='nofollow ugc noopener noreferrer'><u>https://www.usgs.gov/core-science-systems/ngp/national-hydrography</u></a>.</p><p style='background-color:rgb(255, 255, 255); box-sizing:border-box; color:rgb(51, 51, 51); font-family:&quot;Helvetica Neue&quot;, Helvetica, Arial, sans-serif; font-size:16px; font-style:normal; font-variant-caps:normal; font-variant-ligatures:normal; font-weight:400; letter-spacing:normal; margin:0px 0px 10px; text-align:start; text-decoration-color:initial; text-decoration-style:initial; text-indent:0px; text-transform:none; word-spacing:0px;'>DWR was the steward for NHD and Watershed Boundary Dataset (WBD) in California. We worked with other organizations to edit and improve NHD and WBD, using the business rules for California. California's NHD improvements were sent to USGS for incorporation into the national database. The most up-to-date products are accessible from the USGS website. Please note that the California portion of the National Hydrography Dataset is appropriate for use at the 1:24,000 scale.</p><p style='background-color:rgb(255, 255, 255); box-sizing:border-box; color:rgb(51, 51, 51); font-family:&quot;Helvetica Neue&quot;, Helvetica, Arial, sans-serif; font-size:16px; font-style:normal; font-variant-caps:normal; font-variant-ligatures:normal; font-weight:400; letter-spacing:normal; margin:0px 0px 10px; text-align:start; text-decoration-color:initial; text-decoration-style:initial; text-indent:0px; text-transform:none; word-spacing:0px;'>For additional derivative products and resources, including the major features in geopackage format, please go to this page: <a style='background-color:transparent; box-sizing:border-box; color:rgb(22, 92, 171);' target='_blank' href='https://data.cnra.ca.gov/dataset/nhd-major-features' rel='nofollow ugc noopener noreferrer'><u>https://data.cnra.ca.gov/dataset/nhd-major-features</u></a> Archives of previous statewide extracts of the NHD going back to 2018 may be found at <a style='background-color:transparent; box-sizing:border-box; color:rgb(22, 92, 171);' target='_blank' href='https://data.cnra.ca.gov/dataset/nhd-archive' rel='nofollow ugc noopener noreferrer'><u>https://data.cnra.ca.gov/dataset/nhd-archive</u></a>.</p><p style='background-color:rgb(255, 255, 255); box-sizing:border-box; color:rgb(51, 51, 51); font-family:&quot;Helvetica Neue&quot;, Helvetica, Arial, sans-serif; font-size:16px; font-style:normal; font-variant-caps:normal; font-variant-ligatures:normal; font-weight:400; letter-spacing:normal; margin:0px 0px 10px; text-align:start; text-decoration-color:initial; text-decoration-style:initial; text-indent:0px; text-transform:none; word-spacing:0px;'>In September 2022, USGS officially notified DWR that the NHD would become static as USGS resources will be devoted to the transition to the new 3D Hydrography Program (3DHP). 3DHP will consist of LiDAR-derived hydrography at a higher resolution than NHD. Upon completion, 3DHP data will be easier to maintain, based on a modern data model and architecture, and better meet the requirements of users that were documented in the Hydrography Requirements and Benefits Study (2016). The initial releases of 3DHP include NHD vector data incorporated into the 3DHP data model. As new elevation-derived hydrography is created for California, that geometry will replace the legacy NHD vectors in the 3DHP dataset. It will take several years for the 3DHP to be built out for California. Please refer to the resources on this page for more information.</p><p style='background-color:rgb(255, 255, 255); box-sizing:border-box; color:rgb(51, 51, 51); font-family:&quot;Helvetica Neue&quot;, Helvetica, Arial, sans-serif; font-size:16px; font-style:normal; font-variant-caps:normal; font-variant-ligatures:normal; font-weight:400; letter-spacing:normal; margin:0px 0px 10px; text-align:start; text-decoration-color:initial; text-decoration-style:initial; text-indent:0px; text-transform:none; word-spacing:0px;'>The FINAL, STATIC version of the National Hydrography Dataset for California was published for download by USGS on December 27, 2023. This dataset can no longer be edited by the state stewards. The current generation of national hydrography data is the USGS 3D Hydrography Program (3DHP). USGS maintains a 3DHP feature service which is updated quarterly, and provides a downloadable dataset that will updated once per year.</p><p style='background-color:rgb(255, 255, 255); box-sizing:border-box; color:rgb(51, 51, 51); font-family:&quot;Helvetica Neue&quot;, Helvetica, Arial, sans-serif; font-size:16px; font-style:normal; font-variant-caps:normal; font-variant-ligatures:normal; font-weight:400; letter-spacing:normal; margin:0px 0px 10px; text-align:start; text-decoration-color:initial; text-decoration-style:initial; text-indent:0px; text-transform:none; word-spacing:0px;'>Questions about the California stewardship of these datasets may be directed to nhd_stewardship@water.ca.gov.</p>