Painted Rock Reservoir, Arizona

There's no fishing, swimming or boating on Arizona's second largest lake, second in size in the area only to Roosevelt Lake. The Painted Rock Reservoir is closed to the public because it is one of the most toxic sinkholes of pesticide contamination in the country. Its water will disappear in a few short months under the scorching summer sun, leaving behind a poisonous legacy. Painted Rock Dam is located northwest of Gila Bend and was constructed in 1959 to control flood waters that periodically damage downstream areas.

The Painted Rock Reservoir has a gross capacity of 2.5 million acre feet (3.1 km³) of storage, but is designed to remain empty most of the time. The reservoir reached full capacity during the 1993 flood events and extensive damage occurred downstream as a result of the high volume of spillwater. During less severe flooding, the dam retains water and releases it relatively slowly until the reservoir is empty. The water is released at a slow rate to minimize downstream damage and still empty the reservoir as quickly as possible (U.S. Army Corps of Engineers, 1977). There is no flow below Painted Rock Dam except during flood events.