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Chesapeake Bay Program - Water Quality and Quantity

The USGS and the Chesapeake Bay Foundation is working together to study how the last 50 years of population growth has affected the overall health of the Chesapeake Bay.


To understand the factors affecting water quality and quantity in the Chesapeake Bay Watershed we propose to:

  • Improve monitoring of nutrients and sediment
  • Define the processes affecting, the sources, transport, residence time, and change of nutrients and sediment in the Chesapeake Bay watershed;
  • Understand hydrologic, water quality, and sediment processes by Physiographic Region
  • Improve simulation (modeling) of groundwater, surface water, nutrients, and sediment processes, sources, and residence time.
  • Assist our Federal, State, and local agencies in targeting nutrient and sediment sources
  • Understand how changing land-use change affects water quality and sediment - sources, transport, and delivery
  • Better define the function of key habitats (forests, wetlands, stream corridors) to adsorb, store, transform, and release nutrients and sediment;
  • Determine what our partners (Federal, State, Local, Universities, Volunteer organizations) are involved in with respect to hydrology, nutrients, and sediment data collection, monitoring, modeling, and transport and delivery processes
  • Improve our understanding of nutrient and sediment processes by Physiographic region
  • Improve existing statistical models being used (SPARROW, HSPF, others)



The Chesapeake Bay (the Bay) is the Nation¿s largest estuary. The Bay historically has supported one of the most productive fisheries in the world and also provides critical habitat for migratory birds of the Atlantic Flyway. Stream corridors throughout the Bay watershed also provide critical habitat for birds and fish (biological resources). As the human population of the Bay watershed has increased (doubled since 1950), the water quality of the Bay and its tributaries has degraded, contributing to reductions in habitat quality and availability and declines in populations of the biological resources of the Bay and its watershed. Nutrients (nitrogen and phosphorus) and sediment are the primary water-quality contaminants that have been determined to cause this degradation. Human population growth also affects the water quantity of the watershed that in turn affects the water quality, habitat, and biological resources.

The Chesapeake Bay Program (CBP), a partnership of Federal (more than 25), State (6 States and the District of Columbia), and local agencies, was formed in the early 1980s to develop and implement management strategies designed to conserve and restore the water quality, habitat, and biological resources of the Bay and its watershed. Although the CBP has been implementing these strategies for more than 20 years, the water quality, habitat, and biological resources of the Bay have not improved to the extent expected. Thus, the CBP and resource managers of the Bay community need to better understand nutrient and sediment occurrence, transport, residence time, and change to better target and implement effective conservation and restoration strategies. The need for improved assessment and coordinated restoration was emphasized in a Government Accountability Office (GAO) report that recommended that the CBP (1) complete efforts to implement an integrated assessment approach, (2) revise its reporting approach to improve the effectiveness and credibility of its reports, and (3) develop a comprehensive, coordinated implementation strategy that takes into account available resources.

Collection, synthesis, and analysis of information on the relation of water quality and quantity to the impact of human activities on land use and to the ability of habitat to support fish and bird populations of the Bay and its watershed are essential to achieving the goals of the CBP. The multidisciplinary expertise of the U.S. Geological Survey (USGS) and the ability of the USGS to evaluate systems at local to regional scales allow the USGS to apply integrated science that provides unique information that will support the Bay community in the coordinated implementation of effective conservation and restoration strategies.

This integrated science will use a combination of monitoring, modeling, research, and assessment to:

  • Provide an improved understanding of the ecosystem to better target implementation of effective conservation and restoration strategies
  • Assess ecosystem change to help evaluate the effectiveness of these management strategies,
  • Understand how land-use change affects water quality,
  • Forecast the potential impacts of increasing human population and climate variability, and
  • Synthesize the findings and provide implications to help policy makers and resource managers adapt improved approaches for ecosystem conservation, restoration, and sustainability.


USGS Project Number: LF00CUM

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