"Fort Bend County Judge Robert Hebert stated that Hurricane Harvey is more like a 800-year event"

500 years, 800 years ... even 1000 years - none of those are timetables that planning for city ^H^H^H^H region the size of Houston should be operating on.

A city that large, that populous and with that much economic activity that is crucial to the world should be using risk models to 10k year events.

This is not unprecedented - Holland's dykes are designed and built to withstand 10k year events:

https://www.nytimes.com/interactive/2017/06/15/world/europe/...

Which American city, if any, plans for anything close to that time scale?

Seems like every city, county, state, etc. screw up planning on less than human time scales - pensions and infrastructure maintenance for instance.

It isn't planning for a time scale though, it is a level of immediate risk mitigation.

Sounds like the city fell asleep at the wheel, or rolled the dice and didn't want to pay for proper drainage. Now the citizens get to pay.

Sounds like the Judge is preparing the country for the fact that nothing will still be done about it.

There was an article from 2016 also on HN today about the risk. Three different experts were quoted saying something along the lines "nothing will be done now, we need to wait for the big flood and 2-4 years after we will build a wall".

The "wall" (actually a more complex thing) was projected to cost 8 bil. A bad flood like the one from today was projected to cost 70+, but people were hoping that we have around 10-20 years to prepare

Models actually showed a disaster of this scale as far back as 2005: http://www.chron.com/news/houston-texas/article/Models-show-...

The City of Houston, which votes Democrat, has actually done a reasonable job of upgrading its infrastructure over the years. For example all roads built/upgraded since the 90s are designed to act as drainage systems.

The problem is that Houston is a big city and its population has been rising very quickly, and the city government's efforts have been insufficient. And since the Texas state government is dominated by gotta-keep-government-small-and-taxes-low Republicans, Houston has received almost no assistance from the state in this regard. We are seeing the results of that today.

Coastal protections are under the purview of the Army Corps of Engineers, a federal institution, one of the most sclerotic of the government institutions, and one of the rare beasts that actually deserve the common cynicism with government action.

There is no way to credibly make this kind of claim. We don't have the data to quantify the recurrence rate of low-probablity events like this, nor can we be sure the the underpinning mechanism isn't changing with time.

If we have a baseline of 500 year flood level at 0.2% and it's well over that then yes there is a basis for making this claim.

I wouldn't make this claim though...

> If we have a baseline of 500 year flood level at 0.2%

That's exactly the point. We don't have that baseline, despite acting as if we do. We would need data going back 5,000 years to do that.

You're right.

But he's going off of what is established, whether that is faulty or not.

So his claim is based on something faulty, but it is based on something.

Your qualm is not with him or his statements, rather with the standards for current 10 year/100 year/500 year estimates.

I don't think I understand what you're saying. To be able to say things about 0.2%/year events, we would need many thousands of years of data on an unchanging system.

This is not true. You can assume a uniform prior and run your model through bayes law and come up with an estimate.

That's called "making things up", but sure.

And why would a judge (And not someone in environmental sciences) be making that claim anyway?!

He's the chief county administrator.