Skip to main content
U.S. flag

An official website of the United States government


Detailed Description

The regions delineated for collection of streamflow and constituent load data for use in Spatially Referenced Regressions on Watershed Attributes (SPARROW) models in the conterminous United States


Public Domain.

USGS Scientific Investigations Report 2019-5069
Figure 1, Estimates of Long-Term Mean Daily Streamflow and Annual Nutrient and Suspended-Sediment Loads Considered for Use in Regional SPARROW Models of the Conterminous United States, 2012 Base Year