A sign of post-Harvey times. © Houston Chronicle
The collision of big data with Hurricane Harvey could unleash a free-market reappraisal of floodplain development that would make the most draconian of floodplain ordinances look like a 90-lb weakling. The signs are already on the horizon.
Interestingly, resistance to limiting development in floodplains has until now most often been associated with an appeal to free-market principles. Basically a caveat emptor approach. But when the “emptors” or buyers shopping for houses don’t have much information on where and how often it floods, the caveats don’t have quite as much meaning as perhaps they should.
This situation may soon be turned on its head. Harvey and other large floods are about to collide with the flood of “big data.” Big data refers to the ability to mine large and unwieldy arrays of information, such as regional data sets of where and how often flooding has occurred. Apps and programs are already appearing that allow buyers to click on a particular parcel or house and find out whether or not a structure has flooded, and what the likelihood of further flooding might be. Buyers will instantaneously have this information at their fingertips. Buyers thus really can beware if they know exactly what to be wary of. This is far more powerful than a “never flooded” sign atop the for-sale sign.
Harvey in particular feeds into this emerging mash-up because Harvey impacted so much of our area. It is true that Harvey impacted overall a relatively small fraction of structures in our area, but the impacts where so widespread across the region that the majority of us that did not flood very likely know someone who was affected by Harvey. Everyone has been affected one way or another. This flood will not leave our memory any time soon. Flooding will be a major factor for anyone buying a house in the next 5 or maybe even 10 years. People buying houses will want to know whether a house flooded. This may become even more important than what school serves the neighborhood. Flooding will emerge as a major issue for people moving to Houston. They will be able to see from afar whether or not there are large swaths of land that don’t flood—with great neighborhoods and good schools.
If buyers can effortlessly know if a house has been flooded, what will that do to property values? If this information doesn’t drive values down, it will certainly keep property values from rising very much at all. And as houses in floodplains (100 year, 500 year, or even a Harvey-year floodplain) begin to lose their value, with each new flood more and more high-flood-risk dwellers will want to take advantage of buyouts and get out of floodplains altogether. Importantly, floodplains will be much less attractive to developers. Who is going to want to risk a multi-million dollar development in an area known to flood? Known to real people and buyers, that is. Not just industry insiders. Development can be a high risk venture—you need every edge you can get. “Doesn’t flood” will be a major edge.
It is indeed ironic that floodplain development could be curtailed in Houston by market forces. The flow of information will not be stopped. And there is no reason we should try to stop it. We should, however, be concerned about the quality of the data. Transparency will be critical. Agencies that have the information need to share it , and they need to be generous in helping the public to understand the data.
No dataset is going to be completely accurate. But it is one thing to be off by a half-foot deep in the floodplain where the water was up to the eaves during Harvey, and quite a different thing to be that much off at the shallow edge of the flooding.
The stickiest question of all will be that of fairness. If easy-to-use apps do indeed materialize and have the effects described here, many thousands of families will lose their only purchase on the American dream, the equity in their house, largely through no fault of their own. There is no easy answer to this question. But Harvey is not giving us easy answers. Only hard questions –the kind that must be answered for Houston to become a resilient urban beacon.
John Jacob
Steven Mikulencak
Charriss York
Watershed Texas 
my house didn’t flood since its built high along with neighbors who have houses built up like mine.the only way im selling if someone give me an offer i cant refuse and homes that didn’t flood close to downtown are a hot commodity and those homes are gonna get even more pricey.
“If this information doesn’t drive [AVERAGE] values down, it will certainly keep [AVERAGE] property values from rising very much at all.”
Slight modification proposed. Houses that flooded will see prices driven down, though I think in a couple of years, will begin to regain value assuming these epic floods end. We have a lot of transient workers who will look for a location for a couple of years, and may be willing to take on the risk of a borderline place that flooded only in Harvey.
Meanwhile, places that never flooded will see a spike in value. In most cases these are already going to be highly-developed neighborhoods, as the older neighborhoods are often the ones built on the highest ground. The lack of flooding will add a premium to the already higher-priced properties. I expect this will average out over the entire metro region.
If possible please cite an example of an app or website that allows prospective homebuyers to check the flooding history of a property.
From my research I have found it to be quite difficult to obtain that information for a specific address.
It would be very informative to see who is compiling that information and how they are doing so.