Flooding in Houston: A Warning about Costs and Benefits

Flooding in Houston: A Warning about Costs and Benefits

Four thousand dollars per square meter. Three hundred and seventy dollars a square foot.

That’s pretty pricey real estate.

According to one analysis, the average price per square foot of a home in Hillsborough County (recently sold) is about $126. If I was in the market for office space, I could rent in downtown Tampa for $23/sqft per year.

What in the world could possibly cost $370/sqft?

According to Dr. Samuel Brody, director of the Center for Texas Beaches and Shores, that’s the cost in flood damage for an additional square foot of pavement in Houston.

Dr. Brody’s analysis is one more fascinating example of what we are able to do with the large volume of data we have collected as a society (and the computing power to crunch it).

And it’s an indication that, in one sense at least, the development of real estate in Houston has gotten really expensive.

We’ve been watching the struggles of this famous Texas town as it has been forced to absorb as much as  20 inches of rain in a 24-hour period (compared to the four inches typical for the entire month of April). The city lies barely above sea level, making low lying areas into murky ponds as the rainwater poured in.

One can say, with justification, that no one is to blame. The weather event is outside the norm, the consequences a surprise.

But Dr. Brody would suggest otherwise. His research translates the mundane and historic weather events into dollars and cents. It’s a sweepingly broad brush, to be sure. The “cost” of new pavement, in flooding, undoubtedly varies to some extent with one’s exact location in the city.

Still, it’s a wakeup call, not only for Houston, but for other cities, especially those (like most Florida cities) sitting at low elevations and prone to receive intense rain events.

If I add to my porch, or my driveway, I won’t pay anything like $370/sqft. I won’t even pay a significant fraction of that cost.

But if my neighborhood shares certain traits with Houston (like low elevation, soil with a slow percolation rate and inadequate drainage), the real cost of my home improvement might be close to that stunning mark.

Multiply my little project by a major office or retail development with thousands of square feet of impervious surface, and that increased cost seems even more likely.

But the cost is born by others, not just (or not even) the one adding the asphalt. It’s also born over time, not in neat monthly installments, but in periodic and to some extent unpredictable events. Mother Nature is an irregular bill collector . . . but one can be certain she will have her due.

This is one of the many reasons we need government.

Government, by regulation, can reduce the indirect costs of individual activity (the “spillover” effects of development, for example) by requiring the one engaging in the “costly” behavior to absorb more of the cost. By taxation and fee collection, government also can spread indirect costs across a larger community with common interests, providing needed assistance to those whose property is damaged and businesses disrupted.

Because one person’s actions (or one business’s actions) can have this sort of outsized effect on others without their consent, we need institutions and policies that reassert a just and equitable distribution of burdens. No private sector entity can or would do this; it’s not what they are built for.

But cities and counties and states? Exactly what they are there for.

So the next time someone complains about development rules about impervious surfaces or the rate of a storm water fee, perhaps we can remind them that these modest expenses are nothing compared to the cost of . . . well, doing nothing.

Somebody pays the price. Government is our means of ensuring those costs are justly distributed.