The Bay was listed as an "impaired water body" under the Clean Water Act because of poor water clarity. Submerged aquatic vegetation (SAV) has declined drastically over the past 30 years due to poor water clarity, which is caused by excess sediment and nutrients. While nutrient sources and transport have been studied since the 1980s, much less is known about sediment sources and their impact on both streams in the watershed and water clarity in the Bay. The CBP needs information on the sources and transport of sediment streams and water clarity so sediment-reduction measures can be improved and more effectively implemented by 2010. The USGS will help provide information through:

• Better define, map, and simulate the processes, landscape settings, and habitats, controlling sources, transport, and residence time of sediment (and phosphorus) in the watershed;
• Provide leadership for improved design and implementation of the nontidal water-quality network to monitor nutrients and sediment;
• Continue to enhance techniques for load computations and trends analysis of nutrients and sediment;
• Relate water-quality findings in the watershed with estuary conditions to better determine the relative impact of sediment and nutrients on water-clarity conditions for SAV;
• Integrate findings from the impact of human activities on land use with improved water quality and quantity models to forecast potential water-quality changes in the future; and
• Synthesize information to improve environmental indicators, assessments, and identify areas in the watershed that would provide the most immediate benefit for implementing tributary strategies