When disaster strikes, people who have stored drinking water will be at a huge advantage, and potentially some risk as neighbors around them search for sustenance.

On any island – Vashon, Bainbridge, or Mercer Island – that crisis is even more dire, because there’s no way to get fresh water onto the island.

In fact, Mercer Island will be one of the most vulnerable cities in the entire Pacific Northwest. It’s a 5-mile long by 2-mile wide suburban oasis, sitting right in the middle of Lake Washington.

That nakedness is also the biggest reason its citizens have made it among the most-prepared cities in the region.

Sue Robboy is one of the Island’s 711 volunteers – 200 of which are Community Emergency Response Team trained, or CERT trained. And those are enormously high numbers for a small city.

“We keep them engaged throughout the year with drills, education,” said Robboy. “So we dive pretty deep on things like search and rescue and what to do in different kinds of emergencies.”

The residents on Mercer Island have to be prepared. Most of the city’s staff don’t live on the island, so if an earthquake hits overnight, the paid professionals won’t be around.

Maps: Mercer Island seismic hazard assessment | Seattle Fault Zone impact on Mercer Island

The seclusion of living on an island is of course part of the appeal of living on Mercer Island, but the reality is, what if the floating bridge that connects Mercer Island to Seattle and the east channel bridge to Bellevue collapse? Tens of thousands of people could be stuck for weeks.

“It forces people to be a little more aware that we’re going be on our own if something happens,” Robboy said. “I explain to them, we only have six police and three fire on duty at any time, and they’re not going to be able to rescue everybody.”

And it’s not just getting help onto the island. Getting off the Island by boat? Don’t plan on it.

“You have something called a seiche. It’s kind of a bathtub effect in Lake Washington,” said Mercer Island Emergency Manager Jennifer Franklin. “And even though it’s not a tsunami, it can damage your boats. It can lower the lake level. And then on top of that, you’re right. Where you going to go? All the other cities are devastated as well. In fact, Mercer Island is one of the best-prepared cities, so I think in some ways, your best bet is here. Yes, if you can get to Eastern Washington, go for it. But you can’t get there by boat.”

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