There are two sets of leases which threaten Davidson Canyon: AZ Cal Portland (aka CalPortland) and the Charles Seel leases. Spanning Davidson Canyon, these potential quarry sites pose a dire threat to this biologically-sensitive riparian area, as well as the Las Cienegas Preserve immediately downstream.
CalPortland (Arizona California Portland Cement) has submitted a mining plan of operations and a reclamation plan. These are available for download below.
CalPortland Mining Plan of Operations
The Importance of Davidson Canyon
Davidson Canyon provides one the most important wildlife migration corridors in Southern Arizona, linking the Santa Rita Mountains to the Empire Mountains in the south to the Rincon Mountains in the north. The area provides important riparian habitat for a diverse flora and fauna, including priority vulnerable species listed under the Sonoran Desert Conservation Plan and threatened and endangered species or species of concern identified by the U.S. Fish & Wildlife Services, including the lowland leopard frog and the long fin dace.
Davidson Canyon contains perennial and intermittent reaches and springs, is in a free-flowing condition, and the water quality data provided by PAG indicates that the water quality is good. Davidson Canyon possesses attributes that make it of exceptional ecological significance. Davidson Canyon is one of the largest drainage into the Cienega Corridor. It is widely recognized as a major contributor to the continued health of the water aquifer in the Tucson Basin. One of the main tributaries to Cienega Creek, it recharges nearly 20% of Tucson’s water supply.
Surrounding lands (Bar V Ranch) have been acquired by Pima County as part of the Sonoran Desert Conservation Plan.
The Davidson Canyon has been added to the Outstanding Arizona Waters and affords up-front protections for these unique resources and prevent degradation of their water quality.
