Recent monsoon rains helped boost flows in the San Pedro River, but the benefits are only temporary in the midst of a historically dry year. The river, which flows about 140 miles through southeastern Arizona, has been threatened by myriad factors including climate change and nearby groundwater pumping.
In late June, an important registering station along the river registered zero flow. The Charleston gage, near Sierra Vista, showed the river as completely dry.
Joanne Roberts, board president of the nonprofit Friends of the San Pedro River, said that it went dry due to a combination of factors — prolonged drought, climate change, mining and other human uses. She said the river had only gone dry one or two times in recorded history.
After those other dry times, Roberts said, the river came back because the groundwater aquifer underneath was able to recharge. Now, that will be more challenging because the aquifer is significantly depleted.
“It is a concern when we're losing the type of system that sustained this area for so many hundreds of years,” Roberts said.
The San Pedro provides critical habitat for a wide range of species, including more than 350 different kinds of birds. A portion of the river is protected under the San Pedro Riparian National Conservation Area, which covers nearly 57,000 acres in Cochise County.
Efforts are underway to recharge the aquifer underneath the San Pedro. A network of eight different sites is helping boost the underground pools that are critical for the river’s flow.
“The work that has been done over these last 30 years is pretty darn impressive,” Roberts said. “The project sites that are completed, they are making a difference.”
