USGS Ohio Indiana Kentucky Water Science Center

Super Gage Network

Ohio River Ohio River

Ohio River at Olmsted, KY

USGS Station ID: 03612600

Available Data

Stream Data: Gage height, discharge, stream velocity
Water-Quality Data: Dissolved oxygen, pH, specific conductance at 25°C, turbidity, water temperature
Atmospheric Data: Precipitation

View data


Station Description

Latitude: 37°10'45"
Longitude: 89°03'30"
Hydrologic Unit Code (HUC): 05140206
Datum: 278.44 feet above NGVD29
Drainage Area: 203,000 square miles
County in which site is located: Pulaski
Site managed by: Murray Field Office

Station Funding

This station is operated and maintained in cooperation with the U.S. Army Corps of Engineers, Louisville District.

USACE logo

Sample Collection and Use

This site is part of the USGS National Stream Quality Accounting Network (NASQAN) program.

  • A major objective of NASQAN is to determine the concentrations and loads of selected constituents delivered by our major rivers.
  • Water-quality samples are collected 14 times per year.
  • Samples are analyzed for nutrients, organic carbon, major ions, trace elements (metals), pesticides, and suspended sediment.  

Why Continuous Monitoring is Important

Each year, a hypoxic zone (water without dissolved oxygen) forms in the northern Gulf of Mexico. This hypoxic zone is caused in part by excess nutrients delivered from the Mississippi River in combination with seasonal stratification of Gulf waters.

  • Excess nutrients promote algal and zooplankton growth.
  • Overgrowth of algae and zooplankton create an abundance of organic matter which is consumed by bacteria as it decomposes.
  • Bacteria consumes oxygen to consume decomposing organic matter which can lead to hypoxia.
  • Stratification means that the composition of the water is not consistent from top to bottom.
  • Fresh water from rivers, which is less dense than salt water can form a layer above denser salt water which prohibits dissolved oxygen from being replenished from the atmosphere.
  • Fish and other organisms that can swim will evacuate hypoxic zones but organisms that aren't capable of evacuating will become stressed or die.

Delivery of excess nutrients, primarily nitrogen and phosphorus, from the Ohio River to the Mississippi River could contribute to hypoxia in the Gulf of Mexico. The USGS Ohio Kentucky Indiana Water Science Center is monitoring each major tributary into the Ohio River for nutrients and using the data collected for models that can compute nutrient concentrations.


USGS Fact Sheet 2015-3041 provides more detailed information about super gages, how they operate, and the data they collect.

Contact Information

Tim Lathrop
(317) 600-2782

Jeff Woods
(317) 600-2762