By Blake Hollingsworth | Staff Writer

The Brazos River basin contains more impaired stream segments than any other in Texas, but the river’s ability to tolerate pollution depends largely on the consistency and volume of its flow.

Much of the Brazos’ pollution challenges stem from how the surrounding land is used, said Dr. Peter Allen, emeritus professor of hydrology and engineering geology. Runoff from agriculture near the riverbanks, the presence of levees and quarries and the growth of wastewater treatment infrastructure all contribute to increased pollutant exposure.

Dams and shallow wells have also changed how water moves through the system. Instead of flowing naturally, the river is now delivered “disjointedly downstream,” often getting extracted before it can return as baseflow, Allen said.

Levees further complicate the issue by preventing the river from naturally flooding its banks and releasing energy, which leads to more erosion.

“As we slow the river down with dams, add more sewer treatment plants and then squeeze the river with levees … we will face more costly problems,” Allen said. “All rivers, as any biological system, have limits to what they can tolerate before reaching a threshold beyond which recovery is extremely difficult and costly, if possible at all.”

The situation is being made worse by the effects of climate change, according to Dr. Thad Scott, director of Center for Reservoir and Aquatic Systems Research and professor of biology.

“The severity of these droughts and floods is likely to get even worse,” Scott said. “We’re probably heading into a period in the history of Earth that’s getting pretty uncertain with what’s going to happen [with the river’s water flow].”

To help manage this uncertainty, the City of Waco is planning to develop a new wastewater treatment plant on the north side of town that will discharge treated water upstream, making it available for reuse in case of drought, according to Scott.

Scott said this kind of indirect reuse could help extend the city’s water supply.

“It won’t be perfect, but it will help sustain us,” Scott said. “We’ve got to find a way to use [surface water] more conservatively … then do projects like this where we’re recycling the resource itself as much as possible.”

Groundwater should be treated as an emergency resource, not a primary supply, since it’s non-renewable in many regions, Scott said. Surface water, though more sustainable, is becoming harder to predict due to changing rainfall patterns.

Scott also pointed to technology as a tool for improving river management; sensors across the Brazos basin now track water temperature, flow rate and nutrient levels in real time. As these systems grow, water authorities will be better equipped to respond to rapid changes.

“The more information they have, the better they can make decisions about what’s going to happen tomorrow,” Scott said.

Public engagement is another key factor, as agencies like the Brazos River Authority hold board meetings that are open to the public, giving residents the opportunity to stay informed and offer input.

“The best thing the public can do is get educated and actively engage the River Authority,” Scott said. “That’s the best way people can make a difference.”