New Science from USGS to Help Water Managers Target Areas to Improve Water Quality

New USGS findings released in the Journal of the American Water Resources Association are accessible at:

New Science to Help Water Managers Target Areas to Improve Water Quality (press release)—New SPAtially Referenced Regression On Watershed attributes (SPARROW) models were developed for seven major regions of the conterminous U.S. Regional total phosphorus and total nitrogen models were developed for six regions: New England and Mid-Atlantic; South Atlantic-Gulf and Tennessee; Great Lakes, Ohio, Upper Mississippi, and Souris-Red-Rainy; Missouri; Lower Mississippi, Arkansas-White-Red and Texas Gulf; and Pacific Northwest. A dissolved solids model was developed for the arid southwest.

These models confirm the importance of urban and agricultural sources as major contributors of nutrients to streams, but provide new information about local and regional differences in nutrient contributions from contrasting types of agricultural (farm fertilizers vs. animal manure) and urban (wastewater vs diffuse runoff from developed land) sources. In some locations, diffuse background sources are a dominant source of nutrients to streams. Information on background sources is often difficult to quantify in local water-quality assessments, yet is needed to develop comprehensive and realistic management goals.

An online, interactive decision support system provides easy access to these newly-developed regional models describing how rivers receive and transport nutrients from natural and human sources to sensitive waters, such as the Gulf of Mexico. In the arid southwest, the system can be used to delineate sources and transport of dissolved solids.

For additional information on these regional models and the decision support system, contact:
Steve Preston,