Zoning Wouldn’t Have Saved Houston

The rain hadn’t stopped falling before numerous commentators blamed Houston’s flooding on a lack of zoning. This is simply untrue.

First, flood-plain zoning focuses on “high-risk” areas, which by definition means areas in the 100-year floodplain. Fannie Mae and Freddie Mac require that homes they mortgage be covered by flood insurance if they are in zone A or V, which means the 100-year floodplain.

But the Houston flooding resulting from tropical storm Harvey was a 1,000-year flood. That means neither zoning nor insurance would have made a difference for the homes outside the 100-year floodplain. At least half of all the homes damaged by Harvey flooding were in the “moderate-risk” zone in the 500-year floodplain but outside the 100-year floodplain, and more were in the low-risk area outside the 500-year floodplain.

Second, zoning is no guarantee that areas will avoid flood damage. Miami-Dade County has zoning. Yet nearly half of the population lives in the 100-year floodplain, and most of the rest live in the 500-year floodplain. No city is going to zone itself out of existence by forbidding development in most of its land area.

Third, as the Antiplanner noted last week, Houston’s low-density development actually makes it less susceptible to flooding. This is supported by my colleague, Vanessa Calder, who observes that more than 60 percent of Houston is permeable, compared with less than 50 percent of New York, Chicago, or Los Angeles. This assumption of many urban planners that low-density suburbs have high rates of impervious development is wrong.

Harvey deluged Houston with trillions of gallons of water, making it the “most extreme rain event” in American history. Given that much rain, says Houston’s Mayor Sylvester Turner, “zoning wouldn’t have changed anything.” If Houston had been zoned, he argues, “We would have been a city with zoning that flooded.” But urban planners have never been shy about twisting the facts to justify their desire to control how everyone else lives.

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7 thoughts on “Zoning Wouldn’t Have Saved Houston

  1. LazyReader

    Texas is the land of virtually no regulations and zoning laws, you can literally build just about anything you want, and wherever you want and the state government cannot interfere. For most Texans this is a nice luxury. Factories and chemical plants can be built by neighborhoods so there isn’t a need to drive several miles out of the urban areas for work. Some can literally walk. Owners are free to run their plants however they see fit and as cheap as possible. With no state regulations, it isn’t illegal to build whatever,
    wherever, whenever. Texas isn’t no stranger to tropical storms, they have had many this current decade, so no one really batted an eye against regulations. However, now that Harvey wreaked it’s wrath…..were shit out of luck, that’s what you get for building a house on a floodplain made of chickenwire and plywood. We can debate zoning and authority issues all we want, but common sense laws save a lot of lives and BILLIONS AND BILLIONS OF DOLLARS. YOU LIVE IN A FLOOD PLAIN YOU BUILD FOR A FLOOD PLAIN Houses on stilts.
    https://i.pinimg.com/736x/83/0b/3e/830b3edd69f26b1520eb754a77afc85d–home-design-software-house-front.jpg
    You live in a windy area, fortified roofs and windows.
    https://i.pinimg.com/originals/2b/f1/5d/2bf15d0fbc5da5fdc5137eafb2364044.jpg
    FOREST FIRES……….concrete doesn’t burn, it’s hard to renovate but doesn’t burn.
    https://static.concretenetwork.com/photo-gallery/images/1200x625Exact_0x75/concrete-homes_16/stone-concrete-home-fox-blocks_771.JPG
    I especially like this house, this house’s foundation and the building are separated by a column sunk into the earth. The house, floats like a barge. So when the flood comes, the house rises with the Water level and is guided back down when the water recedes. Utilities, water, sewage are fed though the column, not via underground.
    https://i.pinimg.com/originals/50/79/ec/5079ec0c4af0e9b71f2b42f2904c0336.jpg

  2. The Antiplanner Post author

    LazyReader said, “Texas is the land of virtually no regulations and zoning laws, you can literally build just about anything you want, and wherever you want and the state government cannot interfere.”

    That’s far from true. Every major city in Texas but Houston and Houston’s largest suburb, Pasadena, has zoning. Houston (and presumably Pasadena) have land-use regulation governing heights, set-backs, etc., they just don’t try to control what use can take place where.

    Texas counties can’t zone. But almost all new development outside of incorporated cities uses deed restrictions (CC&Rs) to limit uses of individual lots. A little more than half the housing in Houston is also under such restrictions. If you live in a neighborhood with such restrictions, you won’t get a chemical plant next to your house.

    So there is lots of regulation at various levels. You are right that the state has little regulation, but that’s not unusual: as far as I know, other than states that border on the Pacific Ocean or are in the Northeast, no state regulates land use; they leave it to cities and counties.

  3. prk166


    But the Houston flooding resulting from tropical storm Harvey was a 1,000-year flood. That means neither zoning nor insurance would have made a difference for the homes outside the 100-year floodplain. At least half of all the homes damaged by Harvey flooding were in the “moderate-risk” zone in the 500-year floodplain but outside the 100-year floodplain, and more were in the low-risk area outside the 500-year floodplain.
    ” ~ anti-olanner

    I’m not sure exactly what you mean by that 2nd statement. Flood insurance would have made a difference for homes that were flooded regardless of their location. Maybe you’re trying to touch on that given the extreme size of the rain fall, most people that were flooded would’ve assumed they were plenty high to remain dry?

    We tend to do things like that. In Grand Forks, I remember before the flood when we had all the snow people were talking about how they were safe since they didn’t get water in the last big flood that was a generation or two ago. Of course they turned out to be wrong. They were bound to be wrong later or sooner. In this case they had record snow falls for the winter combined with a blizzard right before an unusually fast spring melt. There was a record amount of water, it materialized almost all at once and quickly filled all the low spots.

    Bam! Next thing you know 80+% of the city is flooded. Once it drained, they built some new dikes, didn’t rebuild in some low spots that became park land, and moved on in life.

    Fargo’s had their once in a lifetime flood. They didn’t get hit as bad as Grand Forks. They’ve learned their lesson though and are pushing forward with a floodway that would help ensure the Red River doens’t flood the city again.

    Houston’s in a tough spot. They have a lot of development in low areas but haven’t adequately protected them yet. Hopefully they’ll use this as a chance to prevent major (re)building in those low areas. Moving forward they’ll want to find ways of moving that water to places that have room for it so it doesn’t flood homes and businesses.

  4. CapitalistRoader

    We can debate zoning and authority issues all we want, but common sense laws save a lot of lives and BILLIONS AND BILLIONS OF DOLLARS. YOU LIVE IN A FLOOD PLAIN YOU BUILD FOR A FLOOD PLAIN Houses on stilts.

    Even more sensible is to not build on a flood plain unless you can afford to rebuild without other people’s money:

    If Texans living in flood prone areas refuse to tax themselves enough to protect themselves and their property that means that it doesn’t make economic sense to live and work there. One proof of the adequacy of their coastal and flood defenses would be the willingness of private insurers to offer flood policies to residents. The same logic applies to all coastal counties. Ultimately, ending flood insurance subsidies will reduce property losses and put fewer lives at risk.

    Hurricane Harvey and the National Flood Insurance Fiasco: Don’t build in flood plains, and especially don’t rebuild in flood plains
    Ronald Bailey| Reason | Aug. 28, 2017

  5. notDilbert

    The Permeability of the land really has very little to with the risk of flooding. The primary factor is the volume of water involved and time to took to accumulate that water and the size of the total watershed.

    so a typical thunderstorm may have a rainshield that is 25% the size of the watershed and it cross the watershed in 30 minutes even if it dumps rain at 3 in an hour . the drainage system can handle it. BUT if there is a tropical storm that covers the entire watershed for 48 hours and drops rain at 4 inches a hour, the drainage cant keep up and you have massive flooding. It doesn’t matter if its a corn field or a Paved Unban jungle. The math is the same. Too much water in minus the ability of the watershed to absorb or flush the water equals flood.

    SEE Hydrology isn’t that tough …….

  6. prk166


    But the Houston flooding resulting from tropical storm Harvey was a 1,000-year flood.
    ” ~the anti-planner

    I suspect it’s far more rare than that. It looks like some estimates are saying that 10 to 20 trillion cubic feet of water fell on metro Houston in that relatively short period of time.

    BTW, that volume of water is about 300 – 700 times greater than the volume that Texas A & M study so many story tellers cited, 300 – 700 times more water fell on Houston than Texas A & M estimmates that additional storm water / rain gardens / low lands was lost.

    This is storm that was bound to F* things up. As we’ve seen with other similar events, it overwhelms everything.

    For example, in 2000 Hilo got something like 22″ of rain in just 6 hours

    http://hilo.hawaii.edu/~nat_haz/floods/gallery.php

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