Arizona Public Media

 51 Tucson Mountain Park view toward Santa Ritas - Brian P   
I-11 Corridor Initiative

In a recent PBS piece, our Sun Corridor Program Director talks about Sonoran's involvement in the project's development. He goes on to discuss the Environmental Impact Statement process and the critical concept of integrated infrastructure. As always, it is vitally important that stakeholders work together from start to finish.

Watch the Feature


EPA Clean Power Plan

The Sonoran Institute prepares a statement on today's release of the U.S. EPA's Clean Power Rules in order to discuss the platform for our study to be released next month. We will reveal how large-scale solar can do far more in meeting the EPA's emissions targets than originally envisioned in the rule.

Read the News Release

Contacts - Santa Cruz River

Claire Zugmeyer

520.290.0828 x 1143

Ian Dowdy
Sun Corridor Program Director

602.393.4310 x 308

Santa Cruz River Watershed


Santa Cruz River Initiative Overview


View a complete list of publications.

Santa Cruz River Featured Video

Reclaiming an Oasis in the Desert
Tony Paniagua, Arizona Public Media 

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Home Where We Work Arizona Santa Cruz River More on Santa Cruz River Watershed

More About the Santa Cruz River Watershed


The Santa Cruz River watershed is the land that water runs over, under, or through, on its way to the Santa Cruz River. The river begins in Arizona, flows south into Sonora, Mexico, makes a u-turn, and flows north back into Arizona and through Santa Cruz County, Pima County and the City of Tucson. The Santa Cruz River is the only river to cross the U.S./Mexico border twice (see map below, or Download a PDF copy).

The Santa Cruz River and major tributaries sustain one of the country’s largest cottonwood-willow riparian forests and provide habitat to numerous species, including the endangered Southwestern Willow Flycatcher and Gila Topminnow.

The Santa Cruz River:

* feeds agricultural and ecological processes that contribute to local economies;
* increases municipal water supplies;
* sustains invaluable riparian ecosystems in rural and urban areas;
* provides many imporant ecosystem services or benefits to local communities; and
* is central to the culture of the region.

As the primary water resource in Santa Cruz County, the Upper Santa Cruz River (USCR) provides water to communities, farmers, and ranchers. The USCR aquifer (groundwater storage system) is generally shallow with limited capacity and extreme sensitivity to 20110913_SCR_UpdatedWatershed_smlBdrought.

Along the USCR, people and river ecosystems depend upon the same sources of water - notably surface flow in the river and shallow groundwater. Climate predictions forecast longer and more intense droughts for the region which could diminish supplies of water.  Meanwhile, growing populations increase demand for clean water. The EPA has a taskforce that focuses on water quality challenges in the U.S./Mexico border region. One of these challenges centers on the Nogales International Wastewater Treatment Plant, which discharges 15 million gallons of treated effluent (wastewater that has been cleaned to an accepted level) a day into the river in Santa Cruz County. While this discharge creates water quality concerns, the effluent also nourishes the riparian vegetation and recharges the aquifer.


Many local planning and research efforts have focused on assessing the values, threats, and needs of the USCR and associated riparian habitat.

  • In 2004, Santa Cruz County approved a comprehensive land-use plan that identified the USCR as an important regional resource and specifically stated on page 11 that “the Santa Cruz River and its watershed should be conserved and managed as a ‘Living Ecosystem.’ ” Download the plan (pdf).
  • The National Park Service has completed several ecological inventories along the river and is implementing a long-term inventory and monitoring program. Read the inventory reports.
  • In addition to agencies, individual landowners and local organizations have initiated and completed restoration and monitoring programs on private land.
  • In 2006, Santa Cruz County’s Community Development Department, the University of Arizona’s Office of Arid Lands Studies, and the Sonoran Institute mapped the riparian vegetation along the Upper Santa Cruz River. Read About Santa Cruz Riparian Vegetation Map