Oahu residents dodged a major disaster with the March 11 tsunami, city Department of Emergency Management officials said yesterday.

Daniel Walker, the department’s consultant and a retired University of Hawaii seismologist, said ocean run-up data gathered as part of a statewide tsunami observer program showed water rose as high as 17 feet in some parts of Oahu’s North Shore.

“If this tsunami had just been maybe 2 or 3 feet larger, we would have had serious damage throughout the state on all the islands,” he said. “You add … a couple of feet to this event and there would be many places on Kam Highway on the North Shore that would have been flooded.”

There were eye-raising run-up numbers recorded along the North Shore, he said. One such location was an area just northwest of Camp Erdman in Mokuleia.

“I got pretty much double-digit values all along the North Shore of Oahu. In a couple of places, the tsunami had actually crossed Farrington Highway, and even on the Laie side, there was a place where it crossed Kam Highway.”

In Waimea Bay, water rose 16 feet. At Kaiaka Bay Beach Park, water went as high as 8.5 feet.

But while there was extensive damage to sections of Kona on the Big Island and some damage on Maui, destruction on Oahu was confined largely to docking facilities in Haleiwa and the small boat harbor area in Keehi Lagoon.

Walker was one of several speakers at a Department of Emergency Management news conference to announce that April is Tsunami Awareness Month. It commemorates the April 1, 1946, Hawaii tsunami that claimed 159 lives and is considered the most destructive in Hawaii history.

Peter Hirai, deputy emergency management director, said the tsunami offered good examples of what residents should and should not do. Those in tsunami evacuation zones should evacuate as soon as possible while those outside them should stay put and not add to potential traffic tie-ups, he said.

Hirai also reminded people that those in high-rise areas can evacuate “vertically.” The third floor or higher of buildings six stories high or taller are considered safe so long as they are made of reinforced concrete or structural steel, he said.

Residents should check online or in telephone books to see whether their homes, work places, schools and other areas they frequent are inside or outside of tsunami evacuation zones. he said.

People with smartphones and computers are also advised to sign up to receive the department’s alerts via text messaging or email from Nixle.com.

For more tsunami preparation information, go to www1.honolulu.gov/dem.