Notes: As of June 2020 this dataset has been static for several years. Recent versions of NHD High Res may be more detailed than this dataset for some areas, while this dataset may still be more detailed than NHD High Res in other areas.

National Hydrography Dataset (NHD) high resolution NHDFlowline features for California were originally dissolved on common GNIS_ID or StreamLevel* attributes and routed from mouth to headwater in meters. The results are measured polyline features representing entire streams. Routes on these streams are measured upstream, i.e., the measure at the mouth of a stream is zero and at the upstream end the measure matches the total length of the stream feature. Using GIS tools, a user of this dataset can retrieve the distance in meters upstream from the mouth at any point along a stream feature.** CA_Streams_v3 Update Notes: This version includes over 200 stream modifications and additions resulting from requests for updating from CDFW staff and others***. New locator fields from the USGS Watershed Boundary Dataset (WBD) have been added for v3 to enhance user's ability to search for or extract subsets of California Streams by hydrologic area. *See the Source Citation section of this metadata for further information on NHD, WBD, NHDFlowline, GNIS_ID and StreamLevel. **See the Data Quality section of this metadata for further explanation of stream feature development. ***Some current NHD data has not yet been included in CA_Streams. The effort to synchronize CA_Streams with NHD is ongoing.