Faculty and Students at Eagle Creek Dam
July 11, 2013 was an exciting day for the undergraduate researchers and interns from IUPUI’s Center for Earth and Environmental Science and the Rivers of the Anthropocene Summer MURI students. Led by representatives from the United States Geological Survey, including Martin Risch (Research Hydrologist, USGS Indiana Water Science Center) and Scott Morlock (Deputy Director, USGS Indiana Water Science Center) in collaboration with IUPUI professors Jason M. Kelly (History), Pam Martin (Earth Science), and Phil Scarpino (History), students got a first-hand look at Indianapolis’s water infrastructure.
The purpose of the trip was to examine Indianapolis’s attempts to control flooding and water quality by traveling along Eagle Creek, from downtown Indianapolis to Zionsville.
Below is an overview map of the locations that we visited.
View Eagle Creek Field Trip in a larger map
Levees on Eagle Creek, 10th and Lynhurst
The trip began at the USGS Gauge at Lynhurst Dr. and 10th Street in Indianapolis. In order to mitigate flooding, levees have been constructed to control the flow of water. This is why the channel appears to be so straight here. Without human engineering, it is likely that the creek would have meandered more.
One of the responsibilities of the USGS is to monitor flow rates and depth. Throughout the country, they have installed measuring gauges. This gauge is solar powered and regularly sends information to a satellite so that the data can be compared to other points along the river.
USGS Flood Gauge at 10th and Lynhurst, Indianapolis
Levees and flow measurement are central to Indianapolis’s flood control plan. 100 years ago, on March 23, 1913, 5 days of storms led to 12 inches of rainfall. It created one of the most devastating floods in Indiana’s history. Levees were breached and low lying areas were inundated with the rising water. One flood gauge was washed away as the White River topped 30 feet.
In the 1920s and after, federal and city authorities began a centralized plan for flood control which included building levees and modifying channels along the White River’s tributaries.
Eagle Creek was central to the overall scheme, and in the 1960s, construction began on a dam that helped to manage water flow, provide drinking water to the city, and create a recreational lake. The Eagle Creek Dam was completed in 1968 and was the next location for the field trip.
The Eagle Creek Dam is 75 feet high and 5100 feet long. It has 6 tainter gates, which are convex and better limit the stresses on the dam’s architecture.
Eagle Creek Dam, Indianapolis, IN
Participants were able to take a trip inside the dam and get a sense of how it controls 5.6 million gallons of water per day.
Preparing to descend into the dam
Tony having a look around the dam
Tainter gate gauge
The chains opening and closing the tainter gates
Machines controlling the tainter gates
Catwalk above the dam
Determining how much water flows through the dam on a given day requires a series of measurements using devices that range from simple floats to satellite technology that sends data from gauges further upstream.
So, for example, a Tipping Barrel Rain Gauge, which is situated upstream, might collect rainfall data.
If there is a significant amount of water, the dam operators can expect higher flows and may decide to release more water into the creek below the reservoir. This will lower the level of the reservoir and allow them to control how much and when water flows into the city.
There are devices that measure flow, such as a pygmy meter, which captures the velocity of the water.
The USGS uses Bubbler Gauges to measure the depth of streams. This tool releases nitrogen bubbles into the water. The depth of the water determines the rate at which nitrogen is released (deeper water has higher pressure and lowers the release rate, which shallower water has lower pressure and increases the release rate).
Computers collect this data and send it to the USGS headquarters in Washington, D.C., which in turn distributes it to the regional USGS offices. A centralized database is important because water systems are dynamic and interconnected. A flood on the Wabash River, for example, will eventually flow into the Ohio River and then into the Mississippi River. Those who are responsible for controlling water flow in Memphis, Tennessee will be very interested to know if there is flooding on the Ohio. Likewise, agricultural and urban runoff entering the waterways can have significant effects downstream (see, for example, the hypoxic zone in the Gulf of Mexico).
USGS representatives at the Eagle Creek stream gauge in Zionsville
After leaving Eagle Creek Reservoir, the group made a final stop at a USGS monitoring station in Zionsville. There, they met more representatives from USGS who presented some of the most advanced equipment that they use to measure water flow, pollutants, and biological health.
The orange pontoon in the picture to the right is a sonar device that can measure stream flow. Other pieces of equipment are submerged under the water and can send constant reports about chemicals and temperatures.
To learn more about how USGS is monitoring the health of the nation’s rivers, visit their website at http://www.usgs.gov.
Special thanks to Martin Risch, Scott Morlock, Bret Robinson, Tim Lathrop, and Ed Dobrowolski for their informative presentations.