Southern Arizona river rebounding with more fish, less smell

More fish are calling a river near Tucson home, thanks to upgrades at nearby wastewater treatment facilities.

Those water reclamation plants provide the water that flows into the Lower Santa Cruz river. Back in 2013, water quality wasn’t great. There weren’t many fish and a strong odor emanated from the facilities. Since then, Pima County has invested $600 million to upgrade those wastewater treatment facilities.

“We’ve been finding that the water clarity and quality is much improved,” said Claire Zugmeyer, an ecologist with Sonoran Institute who has been tracking the changing river. “We have new fish species that are living in the river.”

A new report released by the Sonoran Institute and Pima County reflects the changes in the river between October 2014 and September 2015. Zugmeyer said at first, they could only find mosquito fish. Now, they’re finding common carp, green sunfish and black bullhead. In addition, the rotten egg smell that once enveloped the area has now been significantly reduced.

“To see clear water and be able to see fish and turtles in the water, it’s a treat, and a lot of people don’t get to do that regularly,” Zugmeyer said.

Zugmeyer said these recent changes have made the river healthier. It’s also helped Pima County’s water supply. The water does not flow as far downstream, because more of it is seeping into Pima County aquifers, where it is stored as groundwater.