Many Oklahomans rely on rivers and lakes in the Arkansas River Basin for drinking water, crop irrigation and hydroelectric power. But the study predicts that up to 28% less water will be flowing through the basin by 2099.

“Climate change is going to have a very large impact on the water resources in Oklahoma,” said Jia Yang, an ecosystem modeler and OSU professor who worked on the study.

Yang and other researchers from OSU used data from the past to establish how climate change, carbon emissions and land use affect flow in the Arkansas River Basin. Once they’d established that relationship, they used trends in those data to predict how flow will look in the future.

Their models show that all rivers in the Arkansas River Basin—the Canadian, North Canadian, Cimarron, Neosho and the Arkansas itself—will see reduced flow in the coming decades. If carbon emissions stay where they are, flow through the rivers is expected to be about 12% lower than it is today. If emissions continue to rise at the current rate, the river will lose almost a third of its flow.

These are just data-based predictions, but Yang says they’re conservative estimates. He said the river could lose more water due to population growth and encroachment of thirsty trees like eastern redcedars.

The study predicts that flows in the Canadian, North Canadian and Cimarron Rivers will decrease the most thanks to rainfall patterns in the western plains. The study authors wrote that household conservation might be particularly important in the Oklahoma City metro, since it will experience these more severe effects.

“River flow reduction is related to everyone, so everybody can do something to help us to mitigate the impact of the reduction,” Yang said.

This study is part of a larger project at OSU to find socially sustainable solutions to make Oklahoma more resilient to climate change.