Super Gage and the History of Floods in New Harmony

Managing the Water Quality of the Wabash River

At over 500 miles long and spanning the entire length of Indiana, the Wabash River is the largest river in the state. More than 65% of Hoosiers live within its watershed and the Wabash and its tributaries provide drinking water for 72% of counties in Indiana.

A super gage in New Harmony was installed in 2019 on the New Harmony Way Bridge across the Wabash River to measure water quality every 15 minutes, 365 days a year. Managed by the U.S. Geological Survey and U.S. Army Corps of Engineers, the gage monitors the temperature, pH, dissolved oxygen, and nitrate and phosphate levels of Indiana’s largest river. This data helps to improve the river’s water quality and helps us better understand how to reduce the river’s nutrient loads before it is carried downriver by the Mississippi River and contributes to the Gulf of Mexico dead zone.

The super gage also keeps track of the height of the river’s water level to monitor for flooding. Floods occur every few years, with the most extensive recent flooding happening in 2011 when the Wabash River reached a gage height of 23.73 feet.

One of the most damaging floods in New Harmony’s history occurred in March 1913 when the river crested at 27.7 feet. In a period of just two days, several states including, Indiana experienced, two to three months’ worth of rain. The Wabash River usually averages 231 feet wide, but the flood of 1913 left the river almost seven miles wide. Another devastating flood occurred in January 1930. This flood was unique in that the heavy rainfall occurred during subzero temperatures, creating ice gorges stretching several miles wide along the Wabash River. The ice turned what would normally be a mild flood into a disastrous one. Ice dams increased the flooding and caused significant damage to farms and homes throughout the county.