Tucked away off County Road 456 in Clanton, a new monitoring system for Walnut Creek has been implemented in a partnership with the Alabama Department of Environmental Management and the United States Geological Survey.

The system, or water gauging station, serves to monitor the height of Walnut Creek over several years, according to Athena Clark with USGS.

“The information we’re providing is just gauge height,” she said. “It’s provided on a real-time (basis).”

The station’s core purpose is to measure the “stage” of the creek, or the height of the water at any given point, and helps the USGS maintain records of several creeks across the state—as well as the country.

The station records the stage every 15 minutes, and every hour sends data to the online database.

“It’s all done by satellite,” Clark said. “It’s rolled into a database used by the USGS. There’s some gauges we’ve collected data from for over 30 years. There’s some that are over 100 years old.”

Water enters the gauge through an intake located in the stream, which serves to monitor the height of the water. Once it is recorded, it is sent to a database run by the USGS, where it can be accessed by anyone online.

Knowing the stage of the water helps determine the discharge, or the velocity of the water at a given point, Clark said.

Discharge, or “flow” of the water, helps to determine several factors, such as flood prediction or the amount of rainfall over a given period of time.

Rick Treece, Supervisory Hydrologist with the USGS, said the plan for the station was to eventually be able to measure flow.

“Right now, it just monitors stage,” he said. “We’re working on a rating curve, and probably in another month, the website will show flow, not just stage.”

The stage and discharge rates help the USGS chart the condition of the creek for environmental research, among other needs, Clark said.

“When you collect samples, you need to know the flow,” she said. “Basically, the equipment you see in the stream is recording the stage. Every 6-8 weeks, (we’re) checking all instruments and getting the discharge in cubic feet per second.”

Knowing the stage and flow also helps determine ADEM standards for the amount of waste water limits allowed to be released into the creek, said David Thompson with ADEM.

“It drives the limit for what we can discharge,” he said. “If you’ve got a a (small) stream, you’ve got to treat wastewater very thoroughly to get it (clean) for the aquatic life.”

Knowing the flow of the water can help determine the quality of the water, such as how many nutrients are found in the creek.

Anthony Robinson with the Clanton Wastewater Treatment Plant said the plant’s allowance of wastewater into the stream was directly tied to ADEM standards set by the flow and stage of the creek.

“They base our permit off the flow and size of the stream, and the nutrients in the stream,” he said.
Robinson said the amount of waste water permitted in a body of water could change if the size of the body of water changed.

“It would raise the amount we can discharge if the flow in the creek increased,” he said. “For example, if I was to discharge into a river, the limits would be higher.”

Clark said while the station was relatively new—it was installed in November of 2014—it would be used over a long time to determine patterns for Walnut Creek.

“They’re maintaining a rating curve,” she said. “It takes several points. We need to collect several stages in several conditions. You need a range in stage and range in discharge to get that curve.”

In addition to helping measure water quality, Treece said it could help those who use the creek for other endeavors.

“Recreational groups (such as) canoers, the stage can tell them if the creek is too dry and rocky, or too high and dangerous,” he said.