Skip to main content

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Beta

Catalog datasets represent a fraction of data in use by active WMA projects. The team is working on including more datasets to provide a complete view of data-in-use. Let us know how your experience is!

Datasets

Water Watch HUC Runoff

Domain: Hydrology

Variables: Runoff

Spatial Resolution: 1:100,000

Temporal Frequency: monthly; quarterly; annual

Temporal Coverage: 1901 - Present

Spatial Extent: CONUS

Source: USGS

Access:

Description:

The estimates of HUC runoff were generated by combining historical flow data collected at streamgages, the drainage basins of the streamgages, and the boundaries of the HUCs. The required steps (listed below) were applied to each individual water-year (WY) from 1901 to the most recent wateryear and to each of the HUC levels (HUC2, HUC4, HUC6, and HUC8). A water-year is defined as the period from October 1 to September 30, and the water-year designation (e.g., 1971) corresponds to the year of the ending date (e.g., September 30, 1971).
1. Streamgages were selected for each water-year based on two criteria: a complete daily flow dataset for the water-year and a reasonably accurate basin boundary. The criterion for an acceptable basin boundary was an estimated drainage basin area within 25% of the basin area recorded in the USGS National Water Information System (NWIS). The streamgage basin boundaries were delineated using the WATERSHED command in ArcGIS and the flow direction grid provided with NHDPlus.
2. Runoff (flow per unit area) was estimated for each basin by dividing the average daily flow for the water-year by the drainage basin area. The runoff was assumed to be uniform over the entire basin area.
3. Each basin was overlain on a geospatial dataset of HUCs to determine the area of intersection between the basin the HUCs. For each basin/HUC combination, the percentage of the basin in the HUC and the percentage of the HUC in the basin were calculated. These percentages were multiplied by each other to compute a weighting factor assigned to the basin runoff value in estimating the runoff for the HUC.
4. The runoff values and associated weighting factors for all basins with any overlapping area with a HUC were combined, and a single weighted-average runoff value was computed for the HUC.

Citation:

Jian, X., Wolock, D., Lins, H., 2008, WaterWatch - Maps, graphs, and tables of current, recent, and past streamflow conditions, U.S. Geological Survey Fact sheet, https://doi.org/10.3133/fs20083031