The National Water Quality Network (NWQN) for Rivers and Streams includes 105 surface-water river and stream sites monitored by the U.S. Geological Survey (USGS) National Water Quality Program. This data release provides streamflow, nutrient, and sediment data collected and analyzed by USGS for sites on the one Mississippi River site and one Atchafalaya River site used to represent contributions to the Gulf of America for water years 1968 through 2024. This dataset includes daily, monthly, and annual summaries of streamflow conditions, discrete water-quality concentrations, annual water-quality loads, and information on water-quality trends. Water quality data was collected at USGS sites 07373420 Mississippi River near St. Francisville, Louisiana and 07381495 (COE) Atchafalaya River at Melville, Louisiana. Streamflow data was collected at U.S. Army Corps of Engineers (USACE) sites 01100Q Mississippi River at Tarbert Landing, Louisiana and 03045Q Atchafalaya River at Simmesport, Louisiana.
There are 6 comma-separated variable (CSV) files included in this data release:
aflow.csv contains annual streamflow data from the USACE sites.
mflow.csv contains monthly streamflow data from the USACE sites.
dflow.csv contains daily streamflow data from the USACE sites.
discqw.csv contains discrete water-quality sample data from the USGS sites.
WRTDS_loads.csv contains estimated loads and concentrations in the Mississippi and Atchafalaya Rivers, and the combined estimated loads to the Gulf of America for 1968-2024.
WRTDS_trends.csv contains estimated percentage changes in flow-normalized loads and concentrations in the Mississippi and Atchafalaya Rivers, and the percentage changes in the combined flow-normalized loads to the Gulf of America over various periods.
