The Xentity team has been providing services to the United States Forest Service (USFS) since 2018 under the National Geospatial Services Indefinite Delivery/Indefinite Quantity (IDIQ) contract. Among our many tasks orders has been maintenance of the USGS National Hydrography Dataset (NHD). The NHD is among the many digital geospatial datasets that map and model the surface water of the United States. The NHD’s “layer” is an authoritative water layer used in many United States Forest Service (USFS) applications such as: Aquatic Surveys, Best Management Practices (BMP) monitoring, Fire Retardant Avoidance Maps, Water Improvement Tracking (WIT), Watershed Condition Framework (WCF), Watershed Classification and Assessment Tracking Tool (WCATT), and Water Rights and Uses (WRU) on which all spatial planning and reporting of accomplishments are documented.
The NHD program supports many USFS projects, subprograms, and program activities. Hence, it is essential to the success of these projects and programs to have a valid dataset of surface waters based on NHD. Xentity, along with partner Critigen / Locana, supported NHD-based editing tasks for the USFS. In doing so, they provided updates that fixed previously criticized features.
A Constant Need
Xentity often works to maintain and update databases of various sorts. The need to maintain, update and improve NHD and Watershed Boundary Dataset (WBD) is a pervasive challenge across the USFS. Periodic edits identified by local Forest data stewards are required to update these data using custom NHD editing tools designed by the USGS, the federal agency responsible for coordinating NHD updates across all ownerships across the United States. Lately, many attributes and nomenclature in the NHD layer for National Forests are not accurate, as determined by the feedback received from Forest resource specialists and partners in state agencies. Inaccuracies include misaligned and/or improper designation of water features, incorrect feature names, improper topology, and network errors (picture shows geometry errors with flow lines).
The solutions provided for this issue dated back to 2016. In February and March of 2016, Forests and/or regions had the opportunity to modify the default NHD water representation (300ft buffer from all water features) for their areas of interest. They wished to accurately represent aerial fire retardant avoidance areas. This allowed fire retardant action plans to follow the 300-foot buffers guidance. This minimized the impact fire season retardant application has on life (human, aquatic) and water quality of riparian ecosystems. The resulting AFRAM maps identified areas to exempt retardant drops. This avoided harming threatened, endangered, proposed, candidate, or sensitive (TEPCS) species or waterways, except in cases where humans are threatened and retardant within avoidance areas could be reasonably expected to alleviate that threat.
The Xentity team worked together to digitize NHD features (springs, streams, rivers, waterways, including Point, Point Event, Line – Large Scale, Flow Direction, Flowline, Area, and bodies of water and integration with coastal bathymetry) on assigned watersheds (HUC-8) in the NHD database. They ranked HUC-12 sub-watersheds by priority for completion. They also digitized new NHD features. Furthermore, they aligned existing features for the specified area of interest according to the USGS NHD collection standards; they performed the collection and alignment of features on all features in the NHD database hosted by the USGS. We aligned/digitized NHD features at a scale of 1:2000. Furthermore, they verified missing names from the Geographic Names Information System (GNIS) and added those to the attribute data. The NHD GDB only added missing GNIS names. In doing so, they helped update, maintain and integrate enterprise data across an important forest program for the USFS.
Keeping Up to Date
Through the digitization of NHD features, we provide the latest updates. Consequently, these updates fixed the features criticized as misaligned or improperly designated. As a result, forest resource specialists and partners can use the data on the NHD’s various features. And hopefully they can do so with the confidence that they are accurate and up to date.
In 2021, Xentity continued to support NHD-based editing tasks for the USFS. This included checks out / checks in the Hydrologic Unit Code level (HUC8) watershed. Also, editing the HUC12 sub-watersheds from the NHD database. We collaborated with State NHD stewards to coordinate data update efforts prior to check-out. Our staff digitized new NHD features and aligned existing features for the specified area of interest according to the USGS NHD collection standards. NHD features were aligned/digitized at a scale of 1:2,000. Our team collaborated with local forest units after successful check-in of the data to initiate quality control by the local Forest unit.