A Popular Arizona Lake Is Forced To Close After Devastating Ecological Disaster

One of Arizona's most popular fishing destinations, San Carlos Lake in Eastern Arizona, has been closed to all fishing and recreational activities as the result of a massive fish kill affecting "approximately 100% of the fish population." In an announcement on June 5, the San Carlos Recreation and Wildlife Department alerted the public to the situation: "Recent drought conditions, combined with water releases from the dam, have resulted in a major fish kill affecting approximately 100% of the fish population within the lake. Decomposing fish may pose health risks to individuals who enter the area or attempt to fish."

This devastating event is a tragedy for the fish and wildlife, but it wasn't entirely a surprise for anyone following conditions here — water levels have been shockingly low at the lake in 2026. An April 3 announcement from the San Carlos Recreation and Wildlife Department reported that the lake was at "1.93% capacity and water levels are continuing to drop as more water is being released." It also warned of the potential for a fish kill, which has now become a reality.

San Carlos Lake was once a veritable oasis in the desert with its 150+ miles of shoreline. It was a popular spot for boating and fishing: Some of the state's largest fish have been caught here, including catfish, largemouth bass, and rainbow trout. Now, there are literally no fish left alive in the lake. So how did this happen?

San Carlos Lake is a reservoir that formed when the Coolidge Dam was built around 100 years ago to help with agricultural irrigation in the area by releasing water from the reservoir. On top of triggering water releases from the dam, droughts also cause water levels at San Carlos to drop — and when water levels decrease dramatically and temperatures rise in summer, varying factors cause oxygen levels in the water to fall sharply. The result is oxygen-depleted waters that cause fish to die. San Carlos has always experienced literal ups and downs in its water levels, hitting the nearly empty point about 20 times. The last occurrence of a catastrophic fish die off was in 2018.

If your summer vacation included fishing and recreation on San Carlos Lake, you'll need to plan an alternative destination. In northern Arizona, Knoll Lake is one of the state's cleanest lakes and a fishing haven with ample trout. The 575-acre Big Lake in Arizona's White Mountains is a stunning destination for fishing and camping. East of Phoenix, Salt River Canyon has some good fishing along with sunset views and swim spots. And on the far west side of the state, Cattail Cove State Park at Lake Havasu has fishing and boating along with fewer crowds. Whichever spot you choose, be sure to obtain an Arizona fishing license.

While you're traveling through Arizona and the Southwest, always use water wisely. Much of the region is currently in a drought with all of Arizona rated as between "abnormally dry" to "extreme drought" by the U.S. Drought Monitor. Everything we do to conserve water could help — especially with conditions bad enough to trigger events that led to the devastating fish kill at San Carlos Lake.