Nutrients And Sediment In The Western Lake Erie Basin

Science Center Objects

Sediment and nutrient runoff (nitrogen and phosphorus) from agricultural and urban land-use practices are of great concern in the Western Lake Erie Basin watersheds. Excessive nutrient inputs can lead to algal blooms that deplete the oxygen available to aquatic plants and animals. The blooms may result in cyanotoxins or cause taste and odor problems to public water supplies.

Building off its existing stream gages in the Western Lake Erie Basin, since 2013 the USGS measures streamflow and collects sediment and nutrient water-quality samples at a growing network of sites in the Maumee River Watershed. Streamflow is measured at all sites and each site is equipped with an autosampler to collect water samples weekly and during storm events.   

The benchmark of the project’s water-quality monitoring includes cross-sectional samples collected across the entire stream width and depth near the streamgage. Cross-section and autosample concentrations are compared to determine how well concentrations from the autosamples match those of a companion cross-section sample. Daily concentrations and loads are calculated and include the following six water-quality parameters.

  • Orthophosphate, also known as dissolved reactive phosphate (DRP)
  • Total phosphorus (TP)
  • Nitrate plus nitrite
  • Ammonia
  • Ammonia plus organic nitrogen, also known as total Kjeldahl nitrogen (TKN)
  • Suspended sediment concentration

The streamgage network also includes some “supergages” that continuously monitor parameters like dissolved oxygen, temperature, specific conductance, turbidity, pH, and nitrate. These “supergages” can alert scientists to unanticipated changes in the stream water quality.

USGS streamflow and water-quality data including nutrient and sediment concentrations and daily, monthly, and annual loads are available on NWIS-Web. The sites, watersheds, and data for the Western Lake Erie Basin (WLEB) projects can also be accessed through the interactive map.

 

Western Lake Erie Basin (WLEB) watersheds of Ohio and Indiana showing the USGS monitoring stations

 

Auto samplers and stage graph for selected Ohio sites

Cross section sampling - wading a stream and bridge deployment