Description: SOURCE: nhd.usgs.govACQUIRED: 2014Nov10 - IFWIS ccoulterThis data set is a complete digital hydrologic unit boundary layer to the Subwatershed (12-digit) 6th level for the coterminous United States. This data set consists of geo-referenced digital data and associated attributes created in accordance with the "FGDC Proposal, Version 1.0 - Federal Standards For Delineation of Hydrologic Unit Boundaries 3/01/02"(http://www.ftw.nrcs.usda.gov/huc_data.html). Polygons are attributed with hydrologic unit codes for 4th level sub-basins, 5th level watersheds, 6th level subwatersheds, name, size, downstream hydrologic unit, type of watershed, non-contributing areas and flow modification. Arcs are attributed with the highest hydrologic unit code for each watershed, linesource and a metadata reference file.
Copyright Text: Natural Resources Conservation Service
Description: This drainage file represents 41 separate drainages in and immediately adjacent to Idaho, contrasting with the Catalog drainage file, which correlates to 16 separate drainages.
Description: These are streams at the 1:100,000 scale, which intersect Idaho.There are additional streams with fish data from the 1;24,000 scale, and also some canals and ditches included. This is the stream/river/creek/flowing water layer used by IDFG staff for GIS mapping and as the base layer for database and web app reference; it is regularly modified and updated by IFWIS as a Versioned layer (ccoulter 2015 Jan15).
Description: Hydro Stream is a measured linear GIS feature class derived from the NHD (National Hydrography Dataset) and extensively edited to include specific data from IDFG (Idaho Fish and Game) hydro (hydrography) data. The project was initiated in 2008 with the objective of updating the 1:100k resolution IDFG measured stream hydro to more closely align with the 1:24k NHD hydro. Because the merging process is complex and the IDFG hydro is actively edited, continuing efforts toward the orginal merger for common use was deemed impractical (2016ccoulter) for the following partial list of reasons:Just as the IDFG stream hydro is actively edited internally, the NHD flowline is actively edited by internal and external users, so both datasets are in continual transition. Further complicating the merge process, the (now archived) IDFG Hydro_Stream_Measured is a whole-stream dataset based on LLID (a concatenation of Longitude and Latitude at the mouth of a stream at the time of feature creation), where NHD is a multi-segmented dataset based on GNIS (Geographic Names Information System) names and other unique numbers used presumably by hydrologists and the data managers who developed it. The technical nature and number of fields inherent to the parent dataset are extraneous to needs of IDFG end users, which would have necessitated additional processing to eliminate those fields. Because IDFG streams for in-house mapping and online reference must render quickly, the number of records in NHD required to display a unique stream impair the speed requirement. Finally, although they were eventually added, the initial lack of date, edit, and note fields in the interim IDFG stream hydro dataset to track what has been edited, when, or by whom complicated management. The emerging measured stream dataset here is based on NHD comparisons and IDFG adjustments.BACKGROUND: Bart Butterfield (et al) developed the original stream geometry and dataset in the 1990s; Tim Williams implemented methods for transferring data from the old to the new system beginning in 2008 with the assistance of Cyndi Coulter. These efforts have been laborious and time-consuming and have taken place over the past decade-plus (ccoulter2019Aug14). Mr. Williams departed suddenly in May 2015 when the new system was nearing roll-out, although many fixes remained to be addressed. Ms. Coulter assumed management of the stream and lake hydro data following Mr. Williams' departure. A concerted effort to resolve lingering inconsistencies took place throughout 2018 and the resulting stream hydro was rolled out in early 2019. Although many issues persist, significant efforts have resolved disparities between IDFG and NHD stream hydro data, as well as a high number of adjustments to the IDFG hydro that will not align with NHD line work. These include both corrections and internal requests for management purposes.
Copyright Text: Idaho Department of Water Resources, United States Geological Survey, StreamNet, Idaho Department of Fish and Game, Idaho Fish and Wildlife Information System, National Hydrography Dataset