The Latest in Water Quality: Nutrients and Sediment
- Quantifying groundwater influence on nitrogen in streams and Chesapeake Bay ...readmore
- Science Summary—Sources, Fate, and Transport of Nitrogen and Phosphorus in the Chesapeake Bay Watershed—Interpretations and Applications of Spatially Referenced Regression on Watershed Attributes (SPARROW) Nutrient Model Results ...read more (9/2014)
- USGS results on phosphorus trends reveal little progress over the past decade. USGS results show phosphorus trends over the past decade do not show improving conditions at a majority of the sites. Water-quality managers call for more actions to increase progress ...read more
- Simulation of Groundwater Flow in the Shallow Aquifer System of the Delmarva Peninsula, Maryland and Delaware—OF 2012-1140
- Flux of Nitrogen, Phosphorus, and Suspended Sediment from the Susquehanna River Basin to the Chesapeake Bay during Tropical Storm Lee, September 2011, as an Indicator of the Effects of Reservoir Sedimentation on Water Quality (August 2012)
- Monitoring the Chesapeake Bay Watershed (July 2012)
- The distribution of nutrient sources and their delivery to the Bay to better target management actions (USGS Circular 1316).
- The transport time of nitrogen in groundwater to help understand the "lag time" between implementing management actions and seeing a water-quality response (USGS Circular 1316).
- Conowingo Dam Above 90 Percent Capacity For Sediment Storage ...read more
- USGS works with CBP to provide "public friendly" overview of sediment sources in the Bay watershed ...view the video
- USGS co-leads special issue of the Journal of Soils and Sediments focused on suspended sediment sourcing to understand surface processes, as well as address management concerns as they relate to stream turbidity and surface water quality. This special issue contains contributions from 29 researchers from studies in Africa, Asia, Europe, and North America that reflect the current state-of-the science on sediment sourcing. (12/2013)
- Science Summary—Water-Quality Improvements Resulting from Suburban Stormwater Management Practices in the Chesapeake Bay Watershed (2/2013)
- Science Summary—Determining Nutrient and Sediment Loads and Trends in the Chesapeake Bay Watershed by Using an Enhanced Statistical Technique (1/2013)
- Science Summary—Sediment Sources and Transport in the Chesapeake Bay Watershed (3/2013)
- Sources and transport of sediment and the impact on stream quality in the watershed (USGS Circular 1316).
- Sediment sources to the Bay includes watershed inputs, erosion of shorelines and wetlands, and ocean inputs (USGS Circular 1316).
USGS Role in Water Quality: Nutrients and Sediment
Chesapeake Bay Program (CBP) partners are working to reduce nutrients and sediment to improve dissolved oxygen, water clarity, chlorophyll conditions in the Bay, and the health of streams. The President's Chesapeake Bay Executive Order (EO) has specific outcomes to improve water quality in the Bay, which is being addressed through the Bay Total Maximum Daily Load (TMDL), and to restore stream conditions in the watershed.
The U.S. Geological Survey (USGS) is providing science, using an adaptive-management framework, to help the CBP partnership more effectively prioritize, monitor, and evaluate the effects of practices designed to reduce nutrients and sediment. The USGS will help meet these needs in three ways:
- Enhance models to improve the understanding of water-quality conditions.
- Expand regional monitoring and explanation of water-quality changes.
- Monitor and assess changes in small watersheds and provide implications about the effectiveness of management practices.
The USGS is enhancing water-quality models so partners can better understand water-quality conditions and target practices where they will provide the most benefit. The primary USGS models include:
- SPARROW (SPAtially-Referenced Regression On Watershed attributes) models, which provide detailed information on the distribution of nitrogen, phosphorus, and sediment loads throughout the Bay watershed. SPARROW model results compliment the CBP watershed model by providing detailed local results to help States and counties further prioritize the locations for management practices to carry out the Bay TMDL and improve stream quality. The U.S. Department of Agriculture is using the SPARROW results to help identify priority areas to meet its EO outcome to implement new conservation practices on four million acres of working lands in high-priority watersheds by 2025.
- A groundwater model of the Eastern Shore to simulate groundwater flow paths and nitrate transport. The model results will be used to
- estimate the amount of nitrogen that is discharged to the Chesapeake Bay and its tributaries, and
- help quantify the transport of nitrogen in groundwater and its influence on the "lag time" between implementation of management practices and improvements in water quality.
The USGS is expanding regional monitoring and the explanation of water-quality changes so that partners can better assess progress toward nutrient and sediment reduction goals. The USGS efforts will include:
- Working with the U.S. Environmental Protection Agency and State partners to enhance the CBP nontidal water-quality network. The network of sites is where streamflow is measured and water-quality samples are collected to document the amount of and changes to nutrients and sediment in the watershed. The CBP partners are adding sites in suburban and agricultural areas to better document the water-quality conditions in these important land areas and provide data to improve models.
- Computing the loads and trends of nutrients and sediment for the sites in the CBP network. New techniques and tools are being developed to better assess change and progress toward TMDL goals.
- Explaining the factors affecting water-quality change in major basins in the Bay watershed. The assessments are planned for the Potomac, Susquehanna, and James River Basins and the Eastern Shore and will help partners better implement practices to meet the TMDL and improve stream quality.
The USGS is working to monitor and assess changes in small watersheds and provide implications about the effectiveness of management practices. The USGS efforts include:
- Implementing monitoring and research in small watersheds to better evaluate the factors affecting water-quality response to management practices. Enhanced monitoring and assessment is being conducted in several small watersheds. The watersheds include Difficult Run, VA (an urban watershed) where the USGS is working with Fairfax County. In Chester River, MD, and Smith Creek, VA, which are agricultural watersheds, the USGS is working with the Natural Resources Conservation Service (NRCS).
- Working with partners to summarize results from previous and ongoing watershed studies to help partners better understand the response in water quality to management practices.