The Nature Conservancy

The Riester Foundation supports efforts of The Nature Conservancy to protect Arizona’s disappearing riparian areas.

For more than 50 years, TNC’s Arizona Program has been working throughout the state for land and water conservation. The Riester Foundation is supporting TNC’s 2030 Goal of protecting and restoring 43 miles of the San Pedro River in Southern Arizona.

Water is life and water security is of special concern in our arid state. The combination of increasing water demands and changing precipitation patterns depletes surface water supplies and puts rising pressure on limited groundwater supplies.

The San Pedro River’s cottonwood-shaded corridor provides critical habitat for millions of migrating birds each year and is one of the last free-flowing rivers in the Southwestern United States.

Some San Pedro River Facts:

• Is a desert oasis supporting more than 300 bird species;
• Supports over 80 species of mammals;
• Supports more than 750 plant species;
• Also supports 12 amphibians, 55 reptiles, 100 butterfly species, and 250 bee species;
• Historically supported 13 native fish species.

Through yearly grants the Riester Foundation is supporting the mapping monitoring effort of the 170-mile binational San Pedro River. For more than 20 years TNC has collected data annually in June to document how much water is present in the river without the influence of recent precipitation providing important information about the health of the watershed.

Two decades of mapping shows that the conservation actions on the upper San Pedro are having a positive impact. The information from this effort has helped TNC and partners design an innovative regional recharge effort to collect stormwater and other water sources and put it back in the underground aquifer to replenish river flows.