Surface water flows and the riparian communities they support in the San Pedro River basin are closely linked to groundwater conditions. Groundwater pumping has been increasing steadily for the past century, and now greatly exceeds the natural recharge provided by rainfall for portions of the basin, especially in the Cananea and Sierra Vista areas. That pumping has already affected the length of surface flow, especially in areas with high well densities or large-volume wells close to the river. Maintaining surface flow in the river will require thoughtful choices about where and how much groundwater is pumped in the future.
Aerial view of the Parks West restoration site overseen by TNC. Taken March 16, 2020.
Conservancy staffers, Dale Turner and Amanda Rebore, helping to map the Sabn Pedro River in Arizona. They use a GPS unit to denote the end of the water flow on the LowerSan Pedro River. They hiked through the Conservancy’s San Pedro Preserve.
Our Approach to Science
The Nature Conservancy’s conservation science program in Arizona engages stakeholders and expertise in applied science and policy to develop new information, ideas, and tools that can help solve some of our most pressing challenges affecting people and nature
Explore Our Science
We are working with partners and stakeholders to accelerate the pace and scale of forest restoration for a healthy Arizona
Mapping the Status of River Streams
Wet/dry mapping provides a low-cost, river-wide snapshot of hydrologic conditions for rivers with interrupted perennial surface flows.
Lisa A. McCauley, John. B. Bradford, Marcos D. Robles, Robert K. Shriver, Travis J. Woolley, Caitlin A. Andrews
Landscape-scale forest restoration decreases vulnerability to drought mortality under climate change in southwest USA ponderosa forest
Drought is projected to increase tree mortality in many western US forests due to climate change and could result in large-scale tree die-offs, altering forest composition and ecosystem services. Tree mortality has also been found to be higher in forests with greater tree density. Southwestern US fo[…]
The Nature Conservancy, in collaboration with the Western Water Assessment and the USDA-Agricultural Research Service, has produced a snowtography handbook to support resource managers, researchers, and practitioners seeking to understand how the arrangement and density of trees, or the size and sev[…]
Climate Change, Forest Restoration Benefits
John. B. Bradford, Robert K. Shriver, Marcos D. Robles, Lisa A. McCauley, Travis J. Woolley, Caitlin A. Andrews, Michael Crimmins, David M. Bell
Tree mortality response to drought-density interactions suggests opportunities to enhance drought resistance
A future of hotter temperatures and less precipitation under climate change could increase tree mortality under drought conditions in dry forests across the western U.S., causing large-scale tree die offs. Restoration projects that reduce densities of overgrown forests can result in lower competit[…]