The Sonoita Creek starts at the Santa Cruz County Fairgrounds in Sonoita, AZ.  It heads southwest and is joined by tributaries from the Santa Rita and Patagonia Mountains. Sonoita Creek is part of the larger Santa Cruz Watershed. The Santa Cruz River flows north, joins the Gila River, and eventually flows into the Colorado River. The major canyons that flow into the watershed are…                      

Figure 8.0-5 USGS HUCs in the AMA Planning Area

Most of Sonoita Creek flows below the surface.  One place to access surface water is the the Nature Conservancy’s Patagonia-Sonoita Preserve on Blue Haven Road.  A few miles downstream, the creek was dammed in 1969 to form Patagonia Lake.  Dam releases and spillway overflow combine with tributaries to form the lower extent of the creek in the Sonoita Creek State Natural Area.

The Sonoita Creek is approximately 30-31 miles long from its source at the Fair Grounds in Sonoita until it joins the Santa Cruz River at Rio Rico

Historically, Sonoita Creek flowed on the surface most of its length and supported indigenous people and a wealth of wildlife.

Underground the water is moving through the rocks, gravels, soil, and sand in the valley.  Tributary washes or arroyos, canyons, and slopes in the watershed drain toward the creek bed.  (In general, water moving through alluvium and soil is called “subflow”.  Water moving through rock in fractures and pore spaces is often called “groundwater”.)

The watershed needs protection because it faces threats from humans and climate change. A healthy watershed with water above and below the surface can support many species. Some of the immediate threats to the Sonoita Creek watershed are mining, degradation of surface plant and soil cover leading to erosion, and contamination from industry, human waste and livestock waste.