Tongan Tsunami Inundates Santa Cruz Harbor

Following last weekend’s tsunami we spoke with Port of Santa Cruz harbormaster Blake Anderson to see how the harbor fared now that they’ve had a few days to assess the damage. The good news is that the main harbor is in decent shape, the entrance is open, and life in the harbor is quickly returning to normal. The bad news is that there’s still quite a bit of damage that will take time to repair. The list ranges from minor inconveniences to some major expenditures. The North Harbor took the brunt of the surge. Flooding damaged 16 vehicles in the parking lot. Flooding in the upper harbor damaged restrooms and electrical equipment and washed soil out of embankments, harming roadbeds and shoreline protection. Three pilings broke. There’s damage to the UCSC rowing docks, and more. But it’s all much better than after the 2011 tsunami.

Joe Donatini of Johnson Hicks Marine Electronics caught this video of the surge invading the upper harbor.

Water drowned the transformers for the upper harbor, so some docks and liveaboards lost electrical power. Importantly, the dredge that keeps the harbor entrance open all season sustained damage, though apparently it should be back up and running early next week. Walking by or sailing into the harbor, visitors wouldn’t notice much amiss, but the current estimate to fix the damage from the tsunami is about $6.5 million.

Anderson said that after the extreme damage from the 2011 tsunami, about 20 boat owners decided to leave the harbor and head offshore before the arrival of this tsunami. Heading for deep water during a tsunami is often a wise move. It turned out fine for the boats that went out. But because of the damage to the dredge, it was difficult to return to the harbor. Some boats ended up having to stay out all night.

Anderson reported that it was likely fortunate that the tsunami came ashore at high tide. Because the tide was high, the parking lots acted more like a flood plain, allowing water to flow over the banks. At low tide the flooding would have been more constrained by the narrow walls of the harbor, potentially causing more damage to boats, docks and the embankment. Anderson estimates the harbor got about 4 to 5 feet of sea-level rise due to the tsunami. The parking lot ‘flood plain’ may have been good for the harbor, but not for the cars in the lot!

The tsunami warning stretched from Alaska to Chile, with only small pockets of damage along that enormous coastline. 99.99% of the coast experienced very minor effects from the tsunami. As in many natural disasters, local impacts can vary widely and be severe. In fact, we’re collecting some information from Tonga, where communications were largely cut off. It sounds as though The Boatyard in Vava’u, Tonga, was largely unscathed and may actually have suffered less damage than Santa Cruz, nearly 5,300 miles away. Unfortunately, that can’t be said for all the Tongan islands. Many are in dire circumstances. If you have more information on Tonga, let us know here.