Lake Patagonia

About Lake Patagonia

The primary purpose of Lake Patagonia is recreation. The dam creates a reservoir used for recreational activities such as fishing, boating, and swimming. The dam is owned by Arizona State Parks (state). It impounds the Sonoita Creek near Rio Rico, I-40 & Railroad.

The dam stands 157 feet tall and stretches 970 feet across, creates a reservoir covering 260 acres, has a storage capacity of 7,540 acre-feet, and collects water from a drainage area of 235 square miles. Completed in 1968, the structure is well into its service life at over 50 years old.

This dam carries a high hazard potential classification, which means that a failure or uncontrolled release of water would likely cause loss of human life. This classification reflects the consequences of failure, not the likelihood — it indicates that people live or work in the area downstream. Its condition is rated satisfactory, indicating no existing or potential dam safety deficiencies are recognized. An emergency action plan is in place for this dam. The most recent inspection on record was 03/13/2024.

At 157 feet, this dam is taller than 99% of all dams in the United States.

Living Downstream

If you live or work downstream of this dam, consider taking these steps: learn your local evacuation routes, check whether your county emergency management office has a dam failure inundation map, and sign up for local emergency alerts. The Arizona dam safety program can provide more specific information about emergency planning for this structure.

Search for dams near your address to see all dams in your area with hazard classifications and safety data.