Sonoita Creek Watershed: A Roadmap to Water Quality
Preserving the Lifeblood of the Watershed
Santa Cruz County, and the Sonoita Creek Watershed, have witnessed unbroken human history for 12,000 years.
The origin of Sonoita comes from the Tohono O'odham name Son 'Oidag, meaning spring field. From the headwaters in Sonoita, Arizona to the confluence with the Santa Cruz River near Rio Rico, Sonoita Creek runs 31 miles and its watershed covers 260 square miles, making it one of the largest in Santa Cruz County.
Historic 1910 map of Santa Cruz County showing Sonoita Creek.
Sonoita Creek Watershed lies in the middle of Santa Cruz County, with the Town of Patagonia at its heart. The Creek flows to the south of Mt. Wrightson, winding its way between the Santa Rita Mountains and the Patagonia Mountains.
The Sonoita Creek Watershed acts as a wildlife corridor for many species, including the endangered jaguar. The cool waters and tall trees offer reprieve from the desert sun for many four-, and two-, legged travelers.
Bobcats are not an uncommon sight at Patagonia Lake State Park and the Sonoita Creek Watershed. ( Arizona State Parks, 2019 )
A curious coatimundi encountered at Patagonia State Park. (Beyond the Tent, 2019)
Hummingbirds offer a colorful treat to birders and outdoor enthusiasts. (Richard Pick, 2013).
Red Mountain, in the Patagonia Mountain Range, acts as a scenic backdrop for the surrounding area, with hiking trails and wildlife corridors. (Kathleen Pasierb, 2018)
Patagonians enjoying a picnic by Sonoita Creek. (Patagonia Museum collection)
The shores of the Creek have been a draw for locals as well, with many picnics taken under towering Fremont cottonwood trees. A past-time still enjoyed along the Patagonia Lake today!
People living in the Sonoita Creek Watershed had deep ties to the land. The Tohono O'odham settled the area and established farming communities.
A rancher working at the Circle Z Ranch outside of Patagonia, Arizona in 1936. (Pomona Public Library)
By the mid-1800s, mining interests and cattle ranching moved in to work the area, relying on plentiful surface and ground water to survive in the rugged landscape.
Ranches popped up in the watershed, raising livestock and horses. The Circle Z Ranch began as a sheep-herding operation in the 1880's that grew into a dude ranch and, in modern days, a vacation destination and conservation area.
Men and women flocked to Sonoita Creek to homestead and start a new life, making or breaking their fortunes in the process. Mining operations dotted the landscape, with closures common in times of national hardship.
A history of hasty mine closures and poor land management have been sources of stress to the Sonoita Creek Watershed.
Waters run orange after iron-rich precipitate leaches out of the Lead Queen Mine after a monsoon storm. (Tucson News Now, 2018)
A baseline of measurements to map the health of the watershed is vital. Monitoring of water conditions provide a historic record of water quality for future comparisons and the background water quality.
Santa Cruz County has been home to extensive mining operations, particularly in the Santa Rita and Patagonia Mountains.
Many of these historic mines are no longer in operation and pose a threat to the local environment due to poor monitoring and insufficient remediation efforts.
Gaps in the collected data are roadblocks to mapping water quality.
Data has been collected intermittently in the southern half of the watershed since the 1940's.
These data gaps are both spatial (in location) and temporal (in time).
Despite this, there are still some impaired areas in the Sonoita Creek Watershed that have been observed.
The Sonoita Creek and associated tributaries have been sampled in the past for water quality, but sampling sites are few and concentrated in the southern part of the Watershed. Despite this, some streams are already classified as impared or non-attaining by the Arizona Department of Environmental Quality (ADEQ) as of February 2019.
Raw copper, one of the 5 C's of Arizona. (Provident Metals, 2019)
Copper concentrations higher than 1.3 mg/L exceed the maximum contaminant level for drinking water. Copper exceedances have occurred in the southern part of the Sonoita Creek Watershed.
Copper toxicity can negatively effect humans and aquatic life.
Copper in the Aquatic Environment:
Fish are more sensitive to copper concentrations in the water (Woody and O'Neal, 2012).
Zinc, in raw and processed forms. (Heinrich Pniok, 2010)
Zinc concentrations higher than 5.0 mg/L exceed the maximum contaminant level for drinking water. Zinc exceedances have occurred in the southern part of the Sonoita Creek Watershed.
Zinc toxicity occurs at high doses, but is usually rare.
Zinc in the Aquatic Environment:
Fish are more sensitive to zinc concentrations in the water (Hogstrand, 2012).
While heavy metal toxicity is a concern, the pH and hardness of surface streams is important in determining watershed health.
Surface water pH that is too low (acidic) or too high (basic) negatively impacts plants and fish that rely on the waters.
Surface water pH in the Sonoita Creek Watershed.
Surface water pH in portions of the southern watershed are acidic, with sampled pH as low as 2.56 in Alum Gulch. This is too acidic for fish species to survive.
Groundwater hardness in the Sonoita Creek Watershed.
Groundwater hardness can affect plumbing infrastructure and plant health. Sample sites have water hardness as high as 560 mg/L calcium bicarbonate (CaCO3), which is very hard and will clog plumbing.
Status of the copper levels in two municipal wells, from the Consumer Confidence Report for the Town of Patagonia.
Town of Patagonia municipal well (55-605595 and 55-605596) sampled copper content is below the Maximum Contaminant Level (MCL) of 1.3 ppm for drinking water.
The Town of Patagonia municipal well samples have been tested for 89 different contaminants, with zero samples exceeding health standards.
Despite exceedances in some nearby streams, the Town of Patagonia well water poses NO measurable risks to human health.
The continued health of the Sonoita Creek Watershed is vital to environmental, economic, and social interests.
Ocotillo overlooking the Sonoita Creek State Park. ( Arizona State Parks, 2019 )
How you can help:
- Come to the Roadmap for Water Quality future meetings!
- Contribute data to the cause! We need any water quality data you may have, including well water reports and stream sampling by September 30, 2019.
- Attend Town of Patagonia Flood and Flow Committee meetings on the 2nd Thursday, 10 am, at the Town Hall!
- Consider volunteer action with stakeholder groups and participate in watershed discussions and committees!
Ensuring Sonoita Creek's legacy as the lifeblood of Santa Cruz County requires a cohesive approach across multiple private and public interest groups.
Red Mountain, shrouded in clouds. (Kathleen Pasierb, 2019)
Here are some of the current stakeholders of the Sonoita Creek Watershed:
Contact Us:
NextGen Engineering, Inc.
- 2424 E. Broadway Blvd., Suite 200, Tucson, AZ 85719
- (520) 561-6467
- admin@ngeneng.com
- www.NGenEng.com
