The Determination of Total Nutrient Loads from the Nanticoke Watershed above the USGS Nanticoke at Bridgeville Gauging Site (USGS 01487000) from Data Provided by an Automated Nutrient Analyzer (Greenspan, Aqualab)
USGS 01487000 NANTICOKE RIVER NEAR BRIDGEVILLE, DE
The Nanticoke Watershed Water-Quality Database (NWWWQDB) is used to
store, manage, and retrieve water-quality data generated by the “Nanticoke River
Watershed” project. The database contains information on sampling stations, samples,
and field and laboratory analyses, queries to extract and analyze data, forms to input and
edit data, a main menu to navigate to forms and specific queries, and a few formatted
report templates. The database is in Microsoft Access 2003 format. Table, field, and table
relationship metadata are stored in the database as properties of those objects. The
software's metadata reporting options can be used to view the information.
This report supplements the map "Geology of the Seaford Area, Delaware" (Andres and Ramsey, 1995). The map portrays surficial and shallow subsurface stratigraphy and geology in and around the Seaford East and Delaware portion of the Seaford West quadrangles. The Quaternary Nanticoke deposits and Pliocene Beaverdam Formation are the primary lithostratigraphic units covering upland surfaces in the map area. Recent swamp, alluvial, and marsh deposits cover most of the floodplains of modern streams and creeks. The Miocene Choptank, St. Marys, and Manokin formations occur in the shallow subsurface within 300 ft of land surface. The Choptank, St. Marys, and Manokin formations were deposited in progressively shallower water marine environments. The Beaverdam Formation records incision of underlying units and progradation of a fluvial-deltaic system into the map area. The geologic history of the Quaternary is marked by weathering and erosion of the surface of the Beaverdam and deposition of the Nanticoke deposits by the ancestral Nanticoke River. Depositional environments in the Nanticoke deposits include fresh water streams and ponds, estuarine streams and lagoons, and subaerial dunes.
OFR46 Storm-Water and Base-Flow Sampling and Analysis in the Nanticoke River Watershed: Preliminary Report of Findings 2002-2004
This report provides initial research results of a storm-water and baseflow sampling and analysis project conducted by the University of Delaware, College of Marine and Earth Studies and the Delaware Geological Survey. Baseflow samples were collected from four tributary watersheds of the Nanticoke River and one station on the Nanticoke River on 18 occasions from March 2003 to June 2004. Water samples were filtered in the field to separate dissolved nutrients for subsequent analysis, and separate samples were collected and returned to the laboratory for particulate nutrient determinations. On each sampling
date, temperature, conductivity, pH, and dissolved oxygen concentrations were determined at each sampling station. The U.S. Geological Survey made stream discharge measurements at each of these sites under a joint-funded agreement with the Delaware Department of Natural Resources and Environmental Control and the Delaware Geological Survey. Together, the
nutrient and discharge data were used to determine the total nutrient loads at five stations and unit loads (normalized to watershed area) at two of those stations on a quarterly and annual basis. Problems with watershed delineation and low quality discharge data limit these calculations for some watersheds. At the same five stations, storm water was collected during six storms from March 2003 to June 2004. Storm-water loadings of nutrients in each watershed were calculated from the concentrations of nutrients in water samples collected at fixed time intervals from the beginning of the storm-water discharge period until recession to baseflow. Measured storm loads were used as the basis for estimating loads from unsampled storms.
These data provide the Delaware Department of Natural Resources and Environmental Control with a more complete picture of the seasonal dependence of nutrient loading to streams in the Nanticoke River watershed and to Chesapeake Bay receiving waters. These may also be used to establish total maximum daily load goals.
The Seaford area geologic mapping project (Andres and Ramsey, 1995) was conducted by Delaware Geological Survey (DGS) staff and focused on the Seaford East (SEE) and Delaware portion of the Seaford West (SEW) quadrangles (Fig. 1). Data evaluated in support of mapping from these quadrangles and surrounding areas are documented in this report.
Data from three streamflow water-quality stations were statistically analyzed to determine the relationships of the major inorganic chemical constituents to specific conductance and to stream discharge. The results show that ion concentrations varied directly with the flow and with specific conductance. A set of regression equations defining these relationships were derived for each of the three stations: Brandywine Creek at Wilmington, St. Jones River at Dover, and Nanticoke River near Bridgeville.
Beaverdam Branch, the Nanticoke River, Sowbridge Branch, and Stockley Branch drain small basins in the Delaware Coastal Plain that are characterized by similar climate, topography, geology, and land use. Withdrawals of ground water and surface water are very small, there is little urbanization, and other man-made effects, which include minor regulation on Sowbridge Branch and construction of drainage ditches in the Nanticoke basin, probably have had minimal effect on the natural hydrologic regimen. These are virtually natural-flow streams, which, because of similar basin characteristics, have nearly identical rates of evapotranspiration and runoff. During the 10-year period, 1959-68, precipitation averaged 40-42 inches annually, runoff averaged 16-17 inches annually, and evapotranspiration averaged 23-25 inches annually.