River Input Monitoring Active

Problem

Elevated nutrient and suspended solid levels in the Chesapeake Bay adversely affect water clarity and dissolved oxygen levels, stressing living resources in the Bay and its tributaries. In 1987, the Chesapeake Bay Agreement called for 40% reduction in controllable nutrients entering the Bay by the year 2000. In 2000, a renewed Chesapeake Bay agreement was created to reinforce and redefine efforts toward these nutrient reductions. In an effort to reduce nutrients and sediments entering the Bay, management strategies have been implemented in the tributary basins. Quantification of loads and trends is useful for assessing the success of these management practices in improving water quality and living resource response.

Objective

Provide concentrations and estimates of loads and trends of suspended solids, nitrogen, phosphorus, and other selected constituents at the James, Rappahannock, Appomattox, Pamunkey, and Mattaponi Rivers.

Relevance and Benefits

The purpose of this project is to collect and analyze water quality data and to calculate and explain load and trend estimates of selected nutrients and suspended solids for five major river basins in the Virginia portion of the Chesapeake Bay watershed. The stations monitored in this study are (1) the James River at Cartersville, the third largest source of freshwater to the Chesapeake Bay at a basin area of 10,206 mi2; (2) the Rappahannock River near Fredericksburg, the second largest contributor of flow to the Bay in Virginia, at 2,848 mi2; (3) the Appomattox River at Matoaca, entering the James River below the Fall Line and constituting approximately 16% of the James River basin, at 1,600 mi2; (4) the Pamunkey River near Hanover, approximately 55% of the York River basin at 1,474 mi2; and (5) the Mattaponi River near Beulahville, approximately 35% of the York River basin at 911 mi2. Water-quality sample collection began in July 1988 for the James and Rappahannock Rivers and in July 1989 for the Appomattox, Pamunkey and Mattaponi Rivers. Base-flow samples are collected every two weeks by both USGS and Virginia Department of Environmental Quality personnel. Approximately 20-25 high-flow samples are scheduled to be collected at each site annually by USGS personnel. Monthly and annual loads are currently estimated using a seven-parameter log-linear-regression model. Trends in load, flow-adjusted concentrations, and flow-weighted concentrations are also estimated annually.

Project Time Period: 1988 to present