Flooding/Storm Surge (insurance, houses, buy)

[Talesin]

It's Washington ~ so you take the bad with the good.

Question: is it historically the same areas year to year, or does it vary widely dependent on the weather patterns?

I saw the warning for the San Juans that the tide was going to be about 1-1/2' higher due to the current storm incoming. Not good if you live on no bank waterfront.

[jacqueg]

Originally Posted by Talesin

It's Washington ~ so you take the bad with the good.

Question: is it historically the same areas year to year, or does it vary widely dependent on the weather patterns?

I saw the warning for the San Juans that the tide was going to be about 1-1/2' higher due to the current storm incoming. Not good if you live on no bank waterfront.

Tides and storm surges, like river flooding, are governed by topography and probability. I believe most states regulate building where "floods" (including tides and storm surges) can be expected to occur. Depending on the state, you may be able to get a waiver to these regs. Rest assured, even if the state is OK with you building a house where flooding is possible, your insurance rates will reflect that geographical fact.

Of course, there are older houses built before such regs. But fewer and fewer all the time...

[pikabike]

Unusual rainfall patterns affect flooding potential, of course, but some places are more vulnerable to start with, as you alluded to with the no-bank comment.

That said, some things are fairly predictable. Tidal range is greater around the times of full or new moons. In addition, around the solstices, tidal ranges are more extreme regardless what year it is, or what the weather is doing. Add both a new or full moon AND a solstice, and the effect is even greater. Now throw in the weather factor: Winter seems to be worse for bringing so-called king tides, probably because the greater precip in November and December combine with the solsticial factor.

Since you cannot move a house uphill during the high-risk times, the way to avoid the problem is to not build in no-bank or low-bank sites in the first place. Even then, soil saturation from tremendous precipitation can damage houses on higher ground, a.k.a. mudslides.

[Ruth4Truth]

Don't forget, the oceans are expanding as they warm, even without polar ice melt. Miami Beach and other parts of Florida are now finding themselves under water more routinely. Though there are other contributing factors in Florida, that process is taking place worldwide. Water expands when it warms. Bear that in mind when you choose a building site or buy a waterfront home. The San Juans are getting dryer, too. The fresh water supply is getting short.