Application Story

Located just 15 miles northwest of Waco, Texas is the Lake Waco Wetlands, an environmental project constructed in 2001 to protect the loss of habitat from the rising waters of Lake Waco. This 180-acre site is one of the largest ecological projects of its kind and home to a wide range of aquatic plants, mammals, reptiles, and amphibians, along with countless migratory birds.

The Lake Waco Wetlands also offers an innovative educational experience to local universities. In particular, the wetlands act as an outdoor "classroom" for students and researchers of Baylor University's biology department.

Funded by the U.S. Environmental Protection Agency, one project, in particular, involves researching the effects of different concentrations of phosphorus, a limiting nutrient that is known to stimulate excessive algal and bacterial growth. This causes the depletion of dissolved oxygen, critical for supporting animal life in streams.

"We are currently using the experimental facility to test the hypothesis that a very small amount of additional phosphorus above background concentrations will cause an ecological threshold response." explains Ryan King, Ph.D., an assistant professor at the Center for Reservoir & Aquatic Systems Research at Baylor University. "We are looking to see if there is a sharp change to the ecological structure and function of streams. Ultimately, this information will be used to support the development of numerical nutrient criteria for streams in our region."

Using water supplied from the adjacent Lake Waco Wetlands, water is pumped approximately 400 meters from the wetland to 12 experimental streams at a rate of 600 gallons per minute. The water is split among the streams to sustain realistic flows that support aquatic organisms commonly found in natural streams in the area.

To assist with their research, King and his team are using a HOBO® U30/GSM Remote Monitoring System manufactured by Massachusetts-based Onset (

The system is a state-of-the-art weather station that combines research-grade hardware with built-in GSM cellular communications and HOBOlink™, a web-enabled software platform.

King and his team access the data from the HOBOlink website. "HOBOlink's web interface takes environmental monitoring to a whole new level." says King. "The ability to upload data and change settings without having to visit the field site is extremely useful."

HOBOlink allows the research team to set alarm notifications, relay activations, and manage and control the HOBO Remote Monitoring System from any remote location via the Internet.

The 15-channel remote monitoring system can be configured using a broad range of Onset’s research-grade smart sensors or third-party sensors that can be used with the company's analog sensor port.

"We are using the HOBO U30 to gather real-time data on water level in the wetland, water and air temperature, solar radiation, PAR, rainfall, and electrical current being pulled by the water pump used to run the experimental streams," explains King. To monitor water level, King is utilizing a third-party sensor, a Submersible Depth Transmitter (SDX) manufactured by Stevens.

According to King, the U30 is a critical tool for monitoring the water level in the wetland as well as the electrical current flowing to the pump. If the wetland water level drops below the intake line or the pump shuts off due to electrical or other problems, the experiment would be ruined in a matter of a couple of hours.

"The ability to check the system online at any time is tremendous." says King. "Particularly useful is the alarm function that calls my cell phone and sends emails to numerous users whenever there is a problem or if a sensor falls out of range."

The system is set to log data every five minutes, primarily to ensure an immediate notification if a pump shutdown occurs.

So far, the collected data indicate that the phosphorus dosing experiment has confirmed the team’s hypothesis. "We have seen explosive growth of filamentous algae in streams receiving both low and high phosphorus concentrations, but very little in the control streams where nutrient concentrations are similar to high-quality reference streams in our region." says King.

The HOBO U30 System, according to King, has been instrumental in his research. "We chose this system because of its affordability and function. It does everything we need and more at a very reasonable price. The integration of third-party water level sensors and a current transducer into the existing U30 design worked marvelously," concludes King.