Flowing water is a rare and beautiful sight in Southern Arizona. People are drawn to it. So are wildlife, birds, and livestock who gather in riparian areas to drink, feed and live. But what if this flow is not natural, but is man made, or in the case of Harshaw Creek outside of the town of Patagonia, mine-made?
South32’s Hermosa Project, located in the Patagonia Mountains, has been pumping water from below ground to enable the miners to reach deposits of manganese and zinc. It is then treating and releasing that water into the creek, which crosses Harshaw Rd. four times, the Patagonia San Rafael Rd. three times and Harshaw Creek Rd. twice. The increased flow in recent months has done some damage to the crossings that do not have a hardened base.
“The crossings are getting deeper,” said Bob Proctor, President of the Friends of Sonoita Creek (FOSC), a member of the Town of Patagonia’s Flood and Flow committee, and a longtime resident of the area. “I remember that the creek used to flow all the time, but not so much.”
Taja Vivens, South32’s Communications Lead for the Hermosa Project, told the PRT that the mine is currently discharging up to 2.8 million gallons/day of treated water. According to Vivens, the mine will be discharging 5 million gallons/day during early operations. It will decrease to about 3.74 million gallons/day during sustained operations, and eventually drop to 720,000 gallons/day after mining the zinc deposit is complete. South32’s discharge permit, issued by the Arizona Dept. of Environmental Quality, allows for a maximum discharge of 6.4 million gallons/day.
Residents, the post office, cattle trucks and tourists—both in vehicles and on bicycles—are the primary users of the roads the creek crosses. Acting Patagonia Volunteer Fire and Rescue (PVFR) Chief Zay Hartigan said that so far there have not been any serious accidents at any of the crossings.
“There have been no calls to PVFR yet for swift water incidents,” Hartigan said. “It’s a nuisance and a little increase in danger but it could be a lot more [going forward]. We could have more high-water incidents. It’s real important that it’s factored in when considering the road maintenance and safety.”
Because Harshaw Creek is located within the Coronado National Forest, the Forest Service has final jurisdiction over what improvements to the crossings can be made. Santa Cruz County, however, is responsible for maintaining the roads.
“We will address some of the issues with equipment, material and monitoring [the crossings] more frequently,” Santa Cruz County Manager Jesus Valdez said. “Any substantive improvements need to go through the Forest Service.”
Potential improvements to the crossings range from simply pouring concrete to prevent further erosion, to building a vented low water crossing, to erecting bridges. When asked if the County would fund potential improvements, Valdez responded, “Not us, we don’t have the funds.”
The County is in talks with South32 to have the company assume some responsibility for maintaining the crossings. “South32 is requesting that the County provide a blanket permit to do routine maintenance on the crossings currently impacted,” Valdez said.
“South32 is actively working with stakeholders to identify and execute specific improvements to roads and water crossings,” South32 spokesperson Vivens wrote. “As an urgent matter and as a part of our existing road maintenance agreement with Santa Cruz County, we are working to address improvements to the crossings and conduct more frequent maintenance.”
But drivers, hikers and bicyclists should not expect any major improvements too soon. Coronado National Forest Service Engineering and Minerals Staff Officer Edwin Monin said the project would need to be submitted to the Forest Service if it is determined to be beyond the scope of “routine” maintenance. Any improvements could not be implemented until the Forest service completed a National Environmental Policy Act (NEPA) evaluation, a process that takes an average of three years to complete and can take much longer. (For example, it has taken the Forest Service five years to build the new road to Bog Meadow in the San Rafael Valley.)
FOSC member Proctor has two major concerns about the Hermosa’s discharge into Harshaw Creek: pollution and flooding.
Proctor says that although South32 has a water treatment plant that treats the water before discharging it into the creek, other contaminants—many of them legacies of historic mining in the area—can be picked up by the increased flow and carried downstream, potentially entering the Town’s aquifer. “The water is in pretty good shape [as it leaves the mine], but as it flows down it can pick up contaminants,” Proctor said. For example, he said that when the water leaves the mine, it is testing at 7pH. By the time it reaches the ‘end of flow,’ it is reading 6pH, having become more acidic as it travels down the creek.
Proctor said that during heavy rainfalls, ephemeral tributaries that feed into Harshaw Creek run through abandoned mine sites where they can pick up metals and tailings, potentially increasing contamination levels in the Town’s aquifer. He would like to see an assurance that South32 would provide a water treatment plant for the Town included in the Community Protections and Benefits Agreement currently being negotiated by South32, the County, the Town of Patagonia and Nogales.
As Hermosa has discharged more and more water, Proctor says the creek has been flowing further downstream toward Patagonia. “When they start releasing more [in the future], the water may come into town,” Proctor said, which could increase the danger of flooding.
Proctor said that the creek’s end of flow last summer was located at the intersection of Harshaw Rd and San Rafael Rd. The end of flow now has reached the parking lot of the Arizona Trailhead on Harshaw Rd, just 2.8 miles from the Patagonia Post Office.
“It would help to have check dams and retention ponds downstream from the mine to let some of that water soak back in, and it would also help reduce flooding downstream,” Proctor said. “You want to slow down the streams.”
Trina De La Ossa Wheeldon, who lives on Harshaw Rd. and runs cattle near the Arizona Trailhead, sees benefits to the increased flow of water.
“I grew up here,” she said. “The creek used to run all the time. This has been such a dry, dry year. The fact that the mine is [discharging] water, and it is flowing for miles and miles, it’s helping our wildlife for miles and miles around. We see coatimundis, bobcats, mountain lions, javalina, and deer all showing up. It helps birds, ranchers, hunters and the economy.”
Zander Ault, who conducts gravel bike tours through the San Rafael Valley, and promotes the area as a destination for bicyclists, said cyclists now need to be more aware of the condition of the creek crossings than in the past.
“Are there significant holes being created by the water flow, which is deteriorating the road bed?” he asked. “There have been two accidents because of new holes in the roadway.
“There’s going to be changes to how we maintain our bikes because of the consistent water flow, as the water deteriorates our bikes’ drive trains. It will be bringing a lot of business to Patagonia Bikes, because they are going to require a lot of maintenance.
“We all are going to have to adapt to the changes we are seeing in the landscape,” he added.
Got an opinion? Send a Letter to the Editor for publication in the print edition of the PRT. Email your submission to editor@prtnews.org. We reserve the right to edit submissions for language, length and clarity.