Disneyland may be threatened by potential failure of a local dam

According to federal engineers, Disneyland may be in danger as a local dam could fail if an intense rainfall occurs.

The 78-year-old Prado Dam, an earth-fill dam across the Santa Ana River, California, was recently evaluated by state engineers and government officials. The evaluation resulted in U.S. Army Corps of Engineers raising its hazard category from "moderate" to "high urgency". Consequently, a huge storm could cause the failure the dam's spillway, flooding the areas between Disneyland Resort in Anaheim to Newport Beach.

"Our concern right now is about the concrete slab of the spillway and how well it will perform if water were to spill over the top of the dam. We will determine whether or not it is as reliable as it should be," Lillian Doherty, the Army Corps' division chief, stated.

Throughout the longest period of the year, the dam is not at risk as it holds little or no water. However, when a sudden storm occurs, the dam should protect the communities downstream. A potential failure could affect 29 communities and more than 1.4 million people.

Plans to repair and modify the aging construction have been raised as part of an attempt to improve infrastructure in the Santa Ana River that initiated in 2002. The modification of the spillway will cost about $880 million but it will not begin until 2021. The U.S. Corps of Engineers mentioned that the dam does not comply with the safety regulations but this does not mean that it will collapse. "The Corps' assessment of the dam doesn't mean that failure is taking place. It means the agency has identified performance concerns that require attention to meet the Corps' rigorous dam safety standards," a press release from the Corps, stated.

The dam's evaluation follows a series of major issues that were identified in California dams. In particular, back in 2017, a spillway at the Oroville Dam crumbled during a storm resulting in the evacuation of more than 180,000 people. Moreover, at the same period, the Corps of Engineers found that the Whittier Narrows Dam, located about 65 kilometers west of Prado Dam, was vulnerable and posed a threat to more than 1 million people.