Planning commission approves four 60-meter MET towers near Aubrey cliffs over wildlife objections

The Coconino County Planning and Zoning Commission on Jan. 29 approved CUP 24-048, allowing four 60-meter meteorological (MET) towers on a portion of the Big Boquias Ranch owned by the Navajo Nation. The towers, proposed by the Navajo Tribal Utility Authority and Pacific Wind Development (Avangrid affiliate), will be unlit and operate up to five years to collect data for potential future wind development. The motion passed with eight votes in favor and one opposed.

The issue drew extended discussion over wildlife and visual impacts. Senior planner Zach Schwartz told commissioners the towers would be approximately 197 feet tall (199 feet if lightning rods are installed) and therefore below the 200-foot threshold that would require FAA obstruction lighting. Schwartz said the applicant’s view-shed modeling shows limited visibility from populated areas but flagged possible visibility to several Hualapai home sites and raised the proximity of the project area to wildlife-designated areas including an Audubon Important Bird Area, an Arizona Game and Fish conservation opportunity area and a locally mapped wildlife corridor near the Aubrey Cliffs and Aubrey Valley.

Commissioners and staff noted that two originally proposed towers located inside sensitive-designation areas were removed from the application before the hearing. Arizona Game and Fish provided written recommendations included in the staff report: minimize MET tower operating time, deploy bird-flight diverters on guy wires (recommended at 10-meter intervals), conduct carcass checks and coordinate with state and federal wildlife agencies. Staff added a condition to avoid siting towers within 500 meters of known prairie dog colonies after consultations with Game and Fish.

Applicants and technical consultants said the towers’ slim profiles and topography limit visual impacts; Avangrid’s representative, Tyler Hoffper, explained the GIS “zone of visual influence” analysis treats observer height uniformly and that apparent gaps on the large-scale map reflect terrain shielding rather than a literal inability to see the tower at close range. NTUA representative Arash Moalemi said NTUA met with the Hualapai Tribe and conducted a site visit to the tower location most likely to be visible from tribal home sites.

Wildlife planner Jessica Simmons told the commission the greatest documented concerns with MET towers involve bird collisions and that formal carcass-survey protocols (used to estimate mortality rates) are more intensive than the monthly, informal site checks staff will perform; she said the monthly checks are intended as an early warning that would trigger more detailed study and coordination with Game and Fish and US Fish and Wildlife Service if problems appear. Commissioners discussed limits of those informal checks and whether a threshold of observed mortality would require removal or further mitigation; staff said the process calls for ongoing reporting and follow-up rather than an automatic removal threshold.

Commissioner discussion split along wildlife-sensitivity lines. Commissioner Best said the project conflicted with comprehensive-plan language to avoid critical wildlife habitat and movement corridors and voted against approval. Other commissioners, including Vice Chair Rob Wilson and Commissioner Ruggles, said the applicant had reduced the scope of the project, proposed standard wildlife-mitigation measures, and had avoided siting towers inside the highest-protection areas; they voted to approve with the recommended conditions.

The commission approved CUP 24-048 with conditions requiring bird-flight diverters on guide wires, carcass reporting by staff visiting the towers (informal monthly checks), cooperation with Arizona Game and Fish and US Fish and Wildlife Service, and a prohibition on siting towers within 500 meters of prairie dog colonies. The permit is limited to four towers and a five-year operating period.

The commission’s approval applies only to this MET-tower application and does not authorize any future wind turbines or larger energy projects; staff and applicants emphasized that future projects would require separate permits and additional environmental review.