Chloride concentrations in this river have historically been high due to natural saltwater springs and seeps from geologic formations. We monitor the water to help assess the progress of human efforts designed to mitigate this problematic salinity.
Website for the Columbia Environmental Research Center with links to staff, publications, databases, field stations, and projects including those on the Rio Grande, burrowing owls, sea turtles, and geospatial technology.
Stream water quality is affected by amount of impermeable surface in the basin; construction; reservoirs; sanitary sewer systems; land use and population density; road salt; animal waste; lawn and agricultural fertilizers, pesticides, and herbicides.
Fact sheet (also available in PDF format) on the ongoing partnership in water resources between the USGS and non-Federal agencies primarily state, tribal, county and municipal agencies with water-resources responsibilities.