CAMANO ISLAND — They call it the Tsunami House.

If high waves ever hit the north side of Camano Island, Brenda and Mike Adams believe their house would withstand the blast.

When the Adams family bought the island property nearly 10 years ago, it was home to a small 1937 cabin. At first the Adams sought to repair the place.

Soon they were deluged with requirements from the Army Corps of Engineers and the Federal Emergency Management Agency to make changes to the structure because it sits on Skagit Bay.

Architect Dan Nelson and his team at Designs Northwest Architects in Stanwood encouraged the Adams family to consider building a new home, one that would weather high velocity tides, high winds and seismic activity.

It wasn’t cheap and it wasn’t easy, but the new house is one that will stay in the Adams family for generations, Brenda Adams said.

“It’s everything we envisioned it would be,” Mike Adams said of the completed house. “Those involved in the design and construction paid particular attention to detail. We really love living here.”

Historically, there are examples of tsunamis in the Salish Sea. In about 1820, according to Tulalip Tribes history and the late local historian Colin Tweddell, an earthquake caused a large portion of Camano Head to slough off into Possession Sound, which in turn caused a tsunami that nearly covered Hat Island and killed many Snohomish Indian people.

About 10 years ago, the Army Corps upgraded a section of Camano Island to FEMA’s stringent V rating — high velocity flood zone. The theory was, if it happened once, it could happen again, Nelson said.

At the time, a Whidbey Island bluff near Oak Harbor was poised for a collapse similar to Camano Head. With such a landslide, a fast-moving tidal wave could have crossed to Camano. The Corps calculated that the neighborhood would have to withstand 7-foot waves and 5 feet of standing water.

It was within those boundaries that Nelson began his work.

Houses in tsunami zones are best built above the ground so that water can flow under them, and the new house’s living quarters had to be at least 7 feet up. (The Corps has since lowered the height requirements for new construction on the same beach.)

Along with project architect Tom Rochon and structural engineer Jason Lindquist, Nelson designed a “floating” concrete foundation slab to which concrete columns were tied with rebar and capped by concrete beams, also tied in with rebar.

Basically, it’s a concrete box. The entire box is designed to move together instead of shimmying and twisting apart, Nelson said.

Contractor JP Land Builder Inc. of Camano built the house, complete with break-away glass doors that open to the water and slide up like a garage door. The “flood room” isn’t considered living space, but it can be used as a cabana. It opens on the street side, too, so the family can walk from the beach side to the entry on the courtyard side.

The foundational concrete is covered with a polished slab that includes radiant heat for the 887-square-foot living quarters. The ceiling and walls are planked with Western red cedar.

The master bedroom opens through sliding, translucent glass doors. Family members climb up a ship ladder to the 198-square-foot sleeping loft.

The house has an industrial look, but it blends in well with the beach and its iconic Northwest setting and is sure to age beautifully, Nelson said.

Because it’s on the beach, the house couldn’t have a traditional below-ground septic system. Instead, it uses an above-ground sand-filter in an architectural concrete sandbox with 3-foot high walls. Septic waste flows into pipes buried in the sand, trickles out and is filtered before dispersing into the ground.

The sand-filter drain field system stole space from the small lot, so a southern-exposure deck was built on top of it. The border is planted with saltwater-tolerable native sea grass.

“We like the sustainable aspects and the environmentally friendly factors,” Nelson said. “But we are most happy that, if lateral waves were to slam against the structure, it wouldn’t crumble.”

Gale Fiege: 425-339-3427; gfiege@heraldnet.com. Twitter: @galefiege.