The Environmental Attribution effort is a geospatial framework to identify potential environmental concerns related to hydropower development. Environmental issues are defined as any ecological, geopolitical, socio-economic, or landscape development concerns arising with regard to hydropower construction or operation. As part of the larger coordinated HydroSource effort, a consortium of geospatial environmental data layers were obtained from HydroSource's Baseline Data. Geospatial data layers are prepared and updated for HydroSource project initiatives and for public use. Datasets are either provided "as-is" or summarized into new derived forms to fully assess potential environmental concerns. Primary geospatial themes within this framework include: 1) Habitats of Endangered Critical Species Act (ESA) listed species, 2) endangered fish species and fish species of concern, 3) fish traits, 4) protected conservation lands, 5) water quality concerns, 6) water use estimates, 7) recreation and aesthetics, and 8) land disturbance and development. ORNL and the HydroSource team prepares and distributes various geospatial datasets and maps for public use on a provisional basis. Please read below for more information.

U.S. Watershed Environmental Attribution Layers

The following geospatial data layers and maps include summarized environmental characteristics per 8-digit hydrologic unit code (HUC-08) watershed (Watershed Boundary Dataset) across the U.S. Watershed-based attribution provides a reconnaissance-level assessment for basin-scale planning and prioritization. Summary maps can be obtained by clicking the map image and geospatial data is available for download in the sidebar to the right. Environmental Attribution data were also derived as part of the New Stream-Reach Development (NSD) Resource Assessment to spatially identify and characterize a broad range of environmental variables overlapping locations containing NSD potential. Please visit the NSD web page for full details and downloadable reports, data, resources. Ongoing efforts by the HydroSource team are underway to update and expand publicly available datasets. Please check back for future data updates and availability.

Fish-Trait Distribution

Traits are characteristics of species’ life history (e.g., maximum size, fecundity), reproductive ecology, or habitat preferences (Frimpong and Angermeier, 2009). Traits can be an efficient way to evaluate landscape-level patterns in fish communities since groups of fish with common traits, rather than individual species, can be considered collectively. Fish distribution data were accessed through NatureServe Animal Downloads and trait information through Fish Traits Database. Traits used in the analysis include: 1) potadromy and anadromy, 2) temporally-restricted spawning seasons, 3) habitat specialists, 4) lotic specialists, and 5) geographically limited ranges. 

Distribution of Federally Listed Fish Species

Fish species recognized under the Endangered Species Act (1973) and fish species falling under the International Union for the Conservation of Nature (IUCN) are helpful in identifying areas of sensitivity to development. IUCN developed a nine tiered ranking status based on evidence of extinction, population changes, geographical range, occupancy, population size, and the availability of data. Fish distribution data were accessed through NatureServe Animal Downloads, whereas species' federal listing and IUCN ranking status were provided by NatureServe Explorer. 

Water Use Distribution

Water rights for water consumption, appropriation, and availability have become a contentious issue within and across legislative boundaries and basins in the United States. Impoundments can modify the timing and amount (e.g., evaporative losses) of water delivered downstream. In addition, upstream regulatory constraints on water timing and availability might govern hydropower operations. Thus, understanding the potential political context associated with development is critical. County-level water use estimates for 2005 were obtained from the US Geological Survey Water-Use Information Program and were re-summarized by HUC08 watersheds. 

Hydrologic Classification

Distribution of hydrologic classes provides a stratified approach to assess potential hydrologic alterations across the landscape. Hydrologic classes were created using statistics calculated from discharge information from 2,618 (unregulated) USGS streamflow gages with reference, semi-disturbance, or pre-dam regulation data. Hydrologic classes are groups of streams that share similar hydrologic properties, (i.e., similarity in streamflow characteristics), and that could respond similarly to impoundment. Hydrologic classes also provide a template to describe ecological patterns, generalize hydrologic responses to disturbance, and stratify research and management needs.