Tempe is forging ahead with upgrades to the Kyrene Water Reclamation Facility to boost reclaimed-water storage and shore up long-term drought resilience. Archaeologists and tribal preservationists warn the work could disturb Los Guanacos, a well-documented Hohokam village site that sits right next to the plant.
City project, federal oversight
City officials say the Kyrene upgrades will expand reuse and recharge capacity as part of Tempe’s broader water-resilience strategy. As reported by KJZZ, the U.S. Army Corps of Engineers has warned that ground disturbance near Los Guanacos could damage archaeological deposits and has already consulted with Arizona tribes to plan construction monitoring. City leaders maintain the work is needed so Tempe can store reclaimed water for future recovery while the region navigates Colorado River cutbacks.
Los Guanacos: a long-recorded site
Los Guanacos (AZ U:9:116) has been on archaeologists’ radar for more than a century. The site lies in the Kyrene and Elliot Road area, and the City of Tempe’s own historic-resources files trace a long history of investigation there. Archaeological data‑recovery and monitoring reports tied to the Kyrene generating station and nearby projects describe courtyard groups, midden deposits and other finds that make the site scientifically significant. Earlier mitigation work is detailed in City of Tempe documents and archived excavation reports housed with archaeological repositories.
Preservation status and tribal concern
Los Guanacos “is considered historically significant,” Tempe’s historic preservation officer told reporters. KJZZ has also reported that the site has been deemed eligible for the National Register of Historic Places and that archaeologists estimate it was occupied roughly between 1150 and 1400 A.D. Tribal representatives and preservation advocates have signaled they plan to watch excavation and grading closely, given the site’s cultural importance.
Why Tempe is pushing the work
City leaders frame the Kyrene upgrades as part of a bigger push to increase local reuse and recharge capacity so Tempe can better withstand reductions in Colorado River supplies. Federal and local officials have sought funding for recharge wells and pipeline construction, and Rep. Greg Stanton’s office lists awards that supported the Kyrene recharge well and related pipeline projects. A Rep. Greg Stanton release outlines past appropriations tied to Kyrene infrastructure.
Past mitigation shows how work can be handled
When utilities and developers disturbed portions of the Kyrene area in the past, agencies required archaeological monitoring and data recovery under federal review. Environmental assessments and data‑recovery reports from earlier Kyrene projects document how on-site monitoring and curated recoveries were used to limit the loss of information while still allowing some construction to go forward. Those archival reports remain the template for how any new mitigation could be designed and implemented. Previous approaches are summarized in tDAR archaeological reports and in EPA permitting documents.
What to watch next
With the Army Corps involved, construction monitoring and tribal consultation will be central to whether the Kyrene project proceeds without harming cultural resources. Key signals to watch include permit filings, any memoranda of agreement that spell out mitigation, and public statements from tribal historic preservation offices or the city clarifying where trenches, grading or recharge work will occur. Federal guidance requires agencies to consider effects on historic properties whenever a federal undertaking could reach archaeological deposits.
Legal implications
When federal agencies or federal permits are in play, Section 106 of the National Historic Preservation Act requires consultation with State Historic Preservation Officers, Tribal Historic Preservation Officers and other consulting parties. Where adverse effects are likely, that process must also include the development of mitigation agreements. Guidance from the Advisory Council on Historic Preservation explains that this can lead to requirements for monitoring, avoidance measures or data‑recovery work before ground-disturbing activities move forward.
