El Niño is threatening California’s fragile coast again – the 1982-83 El Niño opened eyes to the serious erosion risks
Storm waves eroded the dunes from beneath homes in Pajaro Dunes, Calif., on Monterey Bay, during the powerful 1982-83 El Nino. Gary Griggs California’s coastal bluffs and beaches look rugged, but they can be surprisingly fragile in the face of a powerful El Niño.
El Niño is a climate pattern that occurs every few years, swinging between warm and cold phases. During an El Niño, trade winds weaken, causing warm water to shift eastward from the western Pacific toward South America. This warm water moves north along California’s coast as a Kelvin wave, raising sea levels by about 1 to 2 feet (0.3 to 0.6 meters) due to thermal expansion. The phenomenon disrupts weather patterns globally, often bringing heavy rainfall to normally dry areas and droughts to wet regions. In California, El Niño typically intensifies atmospheric river storms—long, narrow bands of moisture that dump torrential rain and cause flooding. The 1982-83 El Niño was one of the strongest on record, with sea levels elevated by nearly 2 feet in San Francisco and about 1 foot in San Diego above predicted high tides.
California’s coastline is highly vulnerable to El Niño because much of its development—homes, piers, roads—was built during a period of mild storms and lower sea levels. During the 1982-83 El Niño, powerful waves and torrential rain stripped millions of cubic yards of sand from beaches, eroded bluffs by over 65 feet in some areas, and destroyed infrastructure like piers, seawalls, and homes. The total damage amounted to $328 million (adjusted to 2025 dollars) to oceanfront property, $87 million to recreational facilities, and $66 million to protective structures. High astronomical tides and elevated sea levels allowed waves to break closer to shore, accelerating erosion. For example, one-third of the Santa Monica Pier was destroyed, and multiple piers along the coast suffered severe damage.
The 1982-83 El Niño caused catastrophic damage in California, including the destruction of one-third of the Santa Monica Pier, severe damage to the Huntington Beach, Paradise Cove, Seal Beach, San Clemente, and Malibu piers, and the collapse of 33 oceanfront homes. In Pacifica, a sandy cliff eroded so rapidly that it forced the relocation of a two-story building and the removal of an entire row of mobile homes. Seawalls and decks were torn apart, and sections of the Pacific Coast Highway suffered flooding, mudslides, and washouts. The economic losses from high seas alone in the 2022-23 winter reached $4.7 billion, mirroring the conditions of the 1982-83 El Niño. These events highlighted the fragility of coastal development built on beaches, dunes, and cliffs.
California’s coastal development boomed from the late 1940s to the late 1970s, a period when storm activity was mild and sea-level rise was not a major concern. The 1978 El Niño served as an early warning, but the 1982-83 event forced a shift in public perception about the safety of oceanfront homes. Building restrictions were tightened, insurance rates rose, and requests for seawall permits increased. However, over time, new residents continued to build and buy oceanfront properties, often outbidding others for homes damaged in previous El Niños. This cycle of rebuilding and exposure to risk persists despite growing awareness of coastal hazards and the increasing frequency of strong El Niños.
The upcoming 2026-27 El Niño is forecast to be one of the strongest on record, with Southern California already experiencing wave damage from an unusually active Pacific hurricane season fueled by El Niño. Coastal communities are preparing by stockpiling sandbags, clearing drainage systems, and creating evacuation plans, but these measures have limits. Seawalls and rock revetments can provide temporary protection but may worsen erosion in the long term by reducing natural sand replenishment. Adding sand to beaches is costly and short-lived. The state’s 2026 climate assessment warns of more intense storms and increased erosion as temperatures and sea levels rise. Some communities may eventually need to retreat from the coast, either through planned relocation or after repeated damage.
California has relied on *coastal armoring* like seawalls and rock revetments to limit erosion during strong El Niños, such as in 1997-98 and 2015-16. While these structures can protect property in the short term, they often lead to the loss of beaches over time by preventing natural sand movement. Beach nourishment—adding sand to eroded beaches—is another common but temporary solution, as waves quickly wash away the imported sand. The article notes that there are few effective long-term solutions to minimize El Niño impacts once it begins. Instead, communities must focus on risk management and adapting to a changing coastline, acknowledging that some areas may eventually need to retreat from the shore.
