Carmel >> Just as big waves wash away carefully constructed sand castles, El Niño threatens to transform Monterey County beaches and coastlines.
Every winter rainy season brings storms and heavy surf that erode shores and wash away sand, which waves return to the coast in summer. But El Niño generates extra rain and higher sea levels, which increases the erosion during intense and windy storms, affecting coastal bluffs and beaches around Carmel, Pacific Grove, Pebble Beach and Monterey.
“Southern Monterey Bay has the most highly erosive beaches in all of California,” said Paul Michel, superintendent of the Monterey Bay National Marine Sanctuary.
Continual rainstorms swelled the waters of Carmel River last week. After 10 p.m. Sunday, a sand barrier built to keep the river from breaching at the Carmel Lagoon was washed away, according to Melanie Beretti, program manager at the Monterey County Resource Management Agency. After considering bulldozing sand back in place, officials expressed concern about it just getting flushed out to sea, so they decided to hold back.
“We need to balance when and how to utilize the sand,” Beretti said.
The beach has been reopened to visitors, and the Resource Management Agency and National Oceanic and Atmospheric Administration continue to monitor the situation to protect the steelhead trout habitat in the lagoon.
This incident could be a small taste of much bigger things to come. Abnormally large storms and big tides could damage roads, bike paths, hiking trails, water lines, sewage systems or even homes close to the coast.
Part of a multi-year cycle, El Niño weather patterns result from variations in ocean temperatures in the Pacific Ocean near the equator. El Niño conditions produce warmer, expanded ocean waters, which means rising sea levels along the California coastline. NOAA scientists predict this El Niño to be among the strongest on record.
Over the past week, the sea level rose inches to even a foot higher than predicted for a season without El Niño, according to UC Santa Cruz geologist Gary Griggs, based on NOAA measurements. The agency’s scientists predict more El Niño-amplified rain storms in the coming weeks.
The erosion of beaches exposes places that aren’t usually affected. Then, the unstable bluffs and cliffs — usually protected by the beach — are subjected to high tides and additional rainfall, eroding them further, said Griggs.
King tides, the highest of high tides that sometimes reach many feet higher than normal sea level, bring an additional element to the mix. The next set of king tides are predicted to hit next week, according to the California King Tides Project. If combined with heavy rain and strong wind, the tides could cause more damage to low-lying coastal areas.
Residents and city officials are not taking any chances. For example, in Pacific Grove, residents are considering whether to buttress the shoreline by building seawalls to protect property or retreat to higher ground further inland and protect the natural shoreline.
“I believe this is a very important question,” said Anthony Ciani, an architect and member of Sustainable Pacific Grove. A small survey conducted by the organization found that people currently seem to favor retreating, he said.
The city of Pacific Grove published a climate change vulnerability assessment last year. They expect sea levels to rise further over the next few decades, and they want to be prepared.
If intense rains, wind-driven waves, high tides and rising sea levels happen at the same time, they can cause substantial flooding and erosion, Michel said. For now, beaches remain open as public works departments monitor the shoreline to determine if more access areas should be closed.
