Last week the U.S. Army Corps of Engineers suspended it's recent decision to declare two stretches of the Santa Cruz river [right, part of the Gila river watershed] as navigable. Designation as a navigable stream means anyone altering the stream or major tributaries by developments, would need a federal permit.
This was expected to impact the proposed Rosemont copper mine and possible housing developments in the area.
The two river stretches were considered navigable because of effluent discharges from wastewater plants. The Corps is reconsidering the decision of two months ago, in light of a Supreme Court decision on the Clean Water Act.