EDITOR'S NOTE: This is the first article in an occasional series on Newport Harbor and its future.
NEWPORT BEACH — Keeping this city above water is going to get harder in the coming years, some officials and experts believe.
For years Newport Beach has used bulkheads, beach sand replenishment, and dredging to keep land and water in their proper places.
But the price of dry land here may turn out to be eternal vigilance. Sea levels are expected to continue to rise, and the city's harbor commission is recommending the bulkheads, or sea walls, around the city be raised to match.
The recommendation came after the commission heard a report — called "Global Warming and Sea Level Rise Effects on Newport Harbor" — from harbor resources manager Tom Rossmiller. While it admits that predictions vary, the report concludes, "There is certainly a very strong case for significant sea level rise."
"This is not an issue that's a pending disaster this week, but we do say that it's a long-term project that the city should start thinking about," harbor commission Chairman Ralph Rodheim said.
The sea walls are mostly at 9 feet above "mean lower low water," a decades-old measurement based on a 19-year average of each day's lowest tide. That's the standard measurement, and the city uses experience to decide how far above it the sea wall should rise, said city engineer Lloyd Dalton.
But not all sea walls meet the city's 9-foot standard, and already they occasionally prove inadequate to handle a big storm surge or an El Niño event. That means flooded streets on the Balboa Peninsula, like the city saw in January 2005.
And there's the future to consider.
The city's sea walls were mostly built in the 1930s and typically last between 50 and 100 years, Dalton said, so they may need to be rebuilt in the next two decades.
Most climate change scientists say the earth will continue to warm, which melts ice and causes sea level to rise. One prediction shows it's 90% likely that sea level will rise by 4.5 inches by 2050, and by more than 8 inches by 2100, Rossmiller told the commission in the report.
Because of all that, the harbor commission is suggesting the city change its policy to raise the sea walls by a foot within 20 years.
That's where things get complicated.
