Playing the odds on flooding

One of the things that Casey Braun says helps her sleep at night is that the deluge that ended up burying the back of her house might be a 1,000-year storm.

Fred Stodieck joked in February that he must be 400 years old because he’s seen four 100-year floods. After last winter, he should probably revise his age to the full half-millennium.

Calling something a this-many year storm is a little misleading. The phrase specifically refers to the odds of a given size flood occurring in any given year.

So, it isn’t that we’ve had five 100-year floods in a person’s lifetime, but that the reels on the big weather slot machine have aligned five times.

If someone had a one in 100, or even one in 1,000, chance of winning a big pot of money, they would be placing bets all the time.

And that’s the bet people make when they build their homes on an alluvial plain or next to a stream or river.

A home isn’t a one-off bet, either. There are homes in the Valley that are around 170 years old, far longer than the lifespan of any one person.

Last week, the county released a study conducted on Pine Nut Creek, a couple of weeks after discussing one for Buckeye Creek. Between the two, it would cost $122 million to reduce the flows from the Pine Nut Mountains on this side. There’s another $7 million or so just to fix the damage from the flooding in Topaz Ranch Estates, much less do anything to slow it down in the future. That’s more than twice the cost of building Muller Lane Parkway and a new judicial center, combined.

One wager we wouldn’t take would be the chances of success for any sort of bonding, even with significant federal aid, passing the electorate. More than one effort to establish some sort of flood district in Douglas County has evaporated after a few years of drought. It took two years of significant flooding in a row in the north Valley before residents sued. The folks we’ve talked to weren’t particularly happy with the resolution of that effort, which settled for $1.3 million, with $850,000 actually going for some infrastructure.

There are places across the country that experience far more dangerous weather than Douglas County, so there are definitely worse bets to make.