Watershed Texas

The author’s son Daniel holds the line level with the first floor of our house in Eastwood.

Staying out of the floodplain is the number one measure that Houston needs to take to reduce impacts from flooding. Overbank flooding from the creeks and bayous is the deepest and most serious kind of flooding. But anywhere in Houston is subject to street or sheet flooding, the kind that occurs when the amount of rain exceeds the capacity of the storm drains. If an Allison lands in your neighborhood–40 inches in ONE day, not 4 like Harvey –and you are not elevated above the level of street flooding, you will get water in your house even if you are far from a bayou or a floodplain. A storm well short of Allison could do the same.

Our forebears knew what to do. They elevated their homes. They built with pier and beam construction 3-4 feet above the grade of their lot. And they very frequently elevated their lots above the grade of the street with fill dirt.

I live in this kind of neighborhood. Just over two years ago I finished building a house in Eastwood (see photo above), a subdivision built about 100 years ago in Houston’s East End.  I am a watershed scientist –thinking about flooding is a habit. I selected Eastwood for the same reason the original developers did –high ground that drains well. We are right in between Buffalo Bayou and Brays Bayou –sounds like an area that should flood right?  Not at all –it is on a ridge in between these two waterways. (OK—you won’t get a nose bleed way up on this ridge—but water knows where to go: away from the ridge!).

The builders of Eastwood took the dirt from the excavation of the streets and piled it on the lots. They then took some of the very first dredge spoil from the first dredging of the Houston Ship Channel and also put that on the lots above the streets. Our lots are still today a good 2 ½ to 3 feet above the street.

The original house on the lot I bought was beyond repair and had been removed. But I elected to build following the pattern of the original houses in Eastwood –most of these old Craftsman are still intact. I put my house on 4-ft beams above the grade of the lot. That gives me a total of over 6 ft above the street.

Six feet—that’s a real buffer, especially considering that I am already on high ground. So when something like Harvey or even a direct hit by an Allison comes along, I am not too worried about my house. This is what piece of mind is all about. Folks in low lying areas get nervous when any rain is forecast. Ask anyone who lives in Meyerland.

Does this cost more than a slab?  Yes it does, but as best I can figure it only added about $5,000 to the cost of my house. The house cost me about $300,000 to build—so the pier and beam added about 1.5% to the cost of the house. Flood insurance is going to cost me at least $12,000 over 30 years. Which gives me greater piece of mind? Which way might be safer from a community perspective?

Now does this add a ridiculous amount of elevation to this house? Not at all. You can see from the picture that the elevation does not distract from the esthetics in the least. And I get one very important additional safety feature—foundation stability.  We have one of the highest concentrations of world-class gumbo clay in Houston. Gumbo clay is a shrinking, swelling foundation-eating monster.  The volume changes effected by these clays can easily crack a slab foundation. With pier and beam—a simple adjustment every 20 years or so is all you need if the doors wont close. If you plant a tree next to a slab foundation on gumbo clay, just go ahead and factor in $20,000 in foundation repair 15-20 years out.  If you live in Houston, you know you want a tree right next to your house!

A pier and beam house is not going to take care of overbank flooding. So just don’t build in the floodplain. For everwhere else—there’s pier and beam.