Water Rights Transfer for Copper Flat Mine Reopening Denied by State Engineer
August 25, 2025 Santa Fe, NM— The State Engineer issued her decision last week denying Tulla Resources’ application to transfer water rights needed to reopen the Copper Flat Mine near Hillsboro in southern New Mexico.
The State Engineer also noted the effects of climate change on New Mexico’s water resources. Quoting a 2006 Office of the State Engineer report, she stated, “New Mexico’s water future will be determined by water demand and availability of our water resources, [and] climate change will likely have a significant impact on both.”
The State Engineer’s decision to deny the water rights application was based upon the hearing examiner’s findings of fact and conclusions of law that the application will impair existing surface and groundwater rights; that the applicant did not meet its burden of proof that it would be able to put the water rights to beneficial use within the 10-year permit term; and that the application is detrimental to the public welfare of the state as it adversely affects New Mexico’s Compact obligations with Texas.
The Copper Flat Mine operated briefly for about three months in 1982, before shutting down and leaving behind a legacy of contaminated groundwater and a toxic pit lake. The mine has not operated since.
The Australian company Tulla Resources Group applied to transfer 2,400 acre-feet per year of groundwater rights on behalf of New Mexico Copper Corporation in order for it to build, operate, and reclaim the open-pit copper mine. Tulla Resources Group is the primary lender to New Mexico Copper Corporation, a wholly owned subsidiary of the Canadian corporation Themac Resources Group, which is itself owned by Tulla Resources Group.
Protestants Percha-Animas Watershed Association, Hillsboro Pitchfork Ranch LLC, Gila Resources Information Project, Ladder Ranch of the Turner Ranch Properties, and the Rio Grande Chapter of the Sierra Club argued that transferring these water rights would harm the water supplies that local communities depend on for household use, crop irrigation, businesses, livestock, and hunting operations.
The protestants also provided testimony that the water rights transfer would damage local waterways, such as the Rio Grande, Las Animas Creek, Percha Creek, and Caballo Reservoir, essential to people, wildlife, and native vegetation, harming riparian habitats that sustain unique Arizona sycamores and the endangered Southwestern Willow Flycatcher.
Charles de Saillan, attorney representing the Hillsboro Pitchfork Ranch, LLC, the Percha-Animas Watershed Association, the Gila Resources Information Project, and the Rio Grande Chapter of the Sierra Club: “This proposed mining operation would have used a tremendous amount of water – 6,100 acre-feet (almost two billion gallons) of water per year for approximately 12 to 14 years. Yet Hillsboro is an arid region. And close by we have a residential community and local businesses; two working ranches; and a truly unique, biologically rich ecosystem along Las Animas Creek. They all depend on water. And a few miles downstream we have the Lower Rio Grande, which is subject to a water compact with Texas. The State Engineer absolutely made the right decision in finding that this proposed water transfer would be detrimental to the public welfare of New Mexico.”
“We particularly appreciate that the Hearing Examiner and the State Engineer recognized the significance of climate change in the decision. Climate change will mean higher temperatures, greater evaporation, less precipitation, and less snowpack to feed our streams and recharge our aquifers. It will mean less water available to New Mexicans.”
Max Yeh, President of the Percha-Animas Watershed Association (PAWA): “This is the second, and more important, of PAWA’s litigation attempts to protect the waters of our area. The members are jubilant over this win. I started getting calls and emails immediately after I sent out the news. In the first litigation, we successfully reduced the mining company’s claimed water rights from over 7,000 AFY to a little over 1,000 AFY. Now, with this denial of the transfer of water rights, the State has agreed that mining low-grade copper at Copper Flat Mine is a misuse of water that threatens the water supply that sustains our lives, our economic well-being, the flora and fauna of the unique natural world in which we live. However, PAWA has been working to protect water long enough to know that the task is not over with this win. The Hearing Officer’s Report is fabulously detailed and considered, but it is also very narrow and fails to address many problems of water use in the interests of public and private welfare which this case gave opportunities to resolve.”
Allyson Siwik, Executive Director, Gila Resources Information Project: “We applaud the State Engineer’s decision to deny the Tulla Resources water rights transfer application since it will impair existing surface and groundwater rights,” said Allyson Siwik, Executive Director of Gila Resources Information Project. “This decision is a tremendous win for water rights owners downstream of the Copper Flat Mine and the riparian ecosystems of Las Animas Creek, Percha Creek and the Rio Grande that would be irreparably harmed by water depletions caused by mine operations and reclamation.”
Dan Lorimer, Rio Grande Chapter Sierra Club: “Water is key to the future in New Mexico. The denial by the Office of the State Engineer of this huge water rights transfer helps New Mexicans prepare for more certain water availability in the time ahead. The Rio Grande Chapter of the Sierra Club has worked to protect New Mexicans from water insecurity and celebrates this ruling as a strong victory for New Mexicans and for the physical environment we live in and love.”
Contacts:
-Charles de Saillan, Attorney at Law, desaillan.ccae@gmail.com, (505) 819-9058
-Max Yeh, President, Percha-Animas Watershed Association, maxwyeh@gmail.com, (575) 895-3300
-Allyson Siwik, Executive Director, Gila Resources Information Project, allysonsiwik@gmail.com, (575) 590-7619
-Bob Cunningham, Co-Owner, Co-Manager, Hillsboro Pitchfork Ranch, LLC, Bcunni4668@aol.com
-Kathy McKinney, Co-Owner, Co-Manager of the Hillsboro Pitchfork Ranch, LLC kathymckinney@sbcglobal.net
