san pedro

Rancher Mike Hayhurst from the Brookline Ranch helped wet dry map the Babocomari River for many years. Mike passed away this year at age 79 and will be missed by many.

It takes a village to save a desert river, including partnerships and persistence.

Twenty-three years ago, The Nature Conservancy (TNC) first sat down with stakeholders from local, state and federal agencies and organizations to see if they could collaborate on hydrologic science along the San Pedro. At the time, there was little agreement about the status or future of the river and its precious waters, and a lot of concern about its future.

This group evolved into the Upper San Pedro Partnership (USPP), 21 entities who have now collaborated for 23 years to use the best science to manage the water resources of the Upper San Pedro. Building consensus between these diverse partners has not always been easy. However, by approaching water management challenges together, decision makers could agree on the most important information gaps and work with both the Bureau of Land Management (BLM) and scientists at the US Geological Survey, the USDA Agricultural Research Service, private engineers and scientists, and others, to build a common body of science to support decision-making. In the coming months, the USPP will launch a new, state-of-the art “Web-based Hydrologic Information Portal” (WHIP) where water data can be accessed.

As the science evolved, it began to provide insights into how to sustain water for both people and nature. Based on this, TNC began to acquire lands and establish conservation easements with private landowners on tracts near the river where precluding high volume pumping in the future would be most important, with the help of BLM and Fort Huachuca in the early 2000’s.

After 2010, several thousand additional acres were acquired by TNC for the protection and recharge of groundwater. These acquisitions were strategically placed where the river would benefit the most. The lands included three subdivisions that were in, or near, bankruptcy when the real estate market crashed. The acquisition was funded by the U.S. Army and Fort Huachuca and the acreage acquired was transferred to Cochise County for long term management.

The first recharge project, at the Sierra Vista’s Environmental Operations Park (EOP), in 2002 served as a “proof of concept” for subsequent projects using either treated effluent or stormwater. Today, the Cochise Conservation and Recharge Network, a collaborative effort between The Nature Conservancy, the cities of Sierra Vista and Bisbee, Cochise County, the Hereford Natural Resource Conservation District, and Fort Huachuca, are working to implement additional projects to increase groundwater supplies ( This includes eight sites that are either operating or in planning stages along the river from near the international border 25 miles north to, and including, the Babocomari River.

After all this work you might wonder, is it making a difference?

Although more work is needed to replenish groundwater supplies, it is significant that the length of flowing river within the SPRNCA has changed little since 1999, aside from one five-mile reach. During a time when the larger Colorado River Basin, of which the San Pedro is a part, is in crisis due to dwindling water supplies, simply maintaining the flows of the San Pedro is a great accomplishment. We’ve just lived through the driest 22-year period in centuries — a megadrought worsened by climate change and rising temperatures, and it has yet to end.

To measure the overall status of the river and its surface flows, BLM and TNC joined forces in 1999 to initiate the “wet dry mapping” citizen science project to map where the San Pedro continues to flow during the driest time of the year — the third week of June.

This June was the 23rd consecutive year of this effort that now engages more than 100 volunteers, including the Friends of the San Pedro River and many other organizations and individuals in two countries. The effort now encompasses over 250 miles of the river and its tributaries throughout the U.S. and Mexico. Details of the program and data analyses have been presented in several scientific articles, and maps are available for download at: (

Over the 23 years of this effort, there has been no statistical difference in the length of flowing river in the SPRNCA, except in the Palominas area, where the flows have actually shown a small but significant increase, and near the Mexico border where they are decreasing. It is likely that the projects that retired high volume pumping near Palominas have contributed toward the improvement. Plans are underway to replenish groundwater near the Mexico border. Yet the future of the San Pedro remains a concern as the long-term drought persists, as do our own needs to meet water demands. While much is still left to do to increase and protect groundwater, the successes we’ve already made center around our willingness to partner and reach across the table to protect and enhance this great river together.

Holly Richter is the Arizona Water Projects Director for The Nature Conservancy in Arizona. Holly’s expertise is in riparian ecology and hydrology, and her work has focused on water management in this region for over 20 years.