Streamflow and Water-Quality Monitoring in Support of Watershed Model Development, Potomac River Basin

WRD PROJECT #: MD151
PROJECT CHIEF: Majedi, Brenda F.
BEGIN DATE: 01-July-2000
END DATE: 31-December-2002

Customers currently supporting the project:

Maryland Department of the Environment
U.S. Geological Survey

Problem

The National Water-Quality Assessment (NAWQA) Program Potomac River Basin study unit (1992-95), indicated that elevated concentrations of nitrogen and phosphorus in surface and ground water in the Potomac River Basin often result from human activities such as manure and fertilizer application. The monitoring program proposed here is designed to support development of a watershed model of the basin that may be used to assess the effects of point and nonpoint nutrient and sediment sources on water quality in the Potomac River.

Objectives

The U.S. Geological Survey (USGS) has responsibility for four objectives in an overall monitoring program designed to support the development and calibration of a watershed model for the Potomac River Basin: restart and operate two currently inactive continuous stream-gaging stations; establish nine new water-quality monitoring stations; plan, coordinate, and oversee sample collection, using USGS and Maryland Department of the Environment (MDE) staff; and manage all data and plan and oversee quality assurance.

Approach

Candidate sites for monitoring were chosen based on existing information and modeling needs. Those sites without adequate historical water-quality data were then prioritized to arrive at proposed monitoring sites. Sites within the Coastal Plain were considered the highest priority. Integrator sites in subunits with none were given high priority, as were sites within any given subunit that could act as indicators of a particularly important land use. The nine highest-priority sites chosen are for the proposed monitoring effort; of these, two require restart of an inactive gage. Automatic samplers will be installed at all feasible sites to collect storm samples; regular base-flow and high-flow samples will also be collected. All samples will be collected using NAWQA protocols and analyzed for nutrients at the National Water-Quality Laboratory (NWQL) in Denver; sediment analyses will be done at the USGS Iowa District Sediment Laboratory.